Note: Descriptions are shown in the official language in which they were submitted.
CA 02805543 2013-02-12
Porphyrin Compounds and Their use as MRI Contrast Agents
FIELD OF THE INVENTION
The present invention relates to water soluble porphyrin compounds useful in
the
field of magnetic resonance imaging (MRI) as contrast agents.
BACKGROUND OF THE INVENTION
Developed in the 1970'0, MRI has rapidly grown into an indispensable and
increasingly popular imaging modality. Owing to its deep tissue penetration,
non-
invasiveness, excellent soft tissue contrast and high spatial resolution, MRI
is used for
diagnosis and treatment monitoring of a wide variety of diseases.
In conventional MRI scans, signals are mainly derived from 1H-NMR peaks of
water and fat molecules present in the body being imaged. The image contrast
of the
tissues is determined by a number of factors, such as proton density, spin-
lattice
relaxation time (T1), and the spin-spin relaxation time (12). Ti is a measure
of how
quickly the longitudinal magnetization vector (Me) of spinning nuclei recovers
towards
the equilibrium direction after a resonant radio frequency (RF) pulse6. T2
relaxation time
is a time constant that describes the dephasing of the transverse nuclear
magnetization.
Since Ti and T2 relaxations vary from tissue to tissue, acquisition parameters
can be
adjusted to differentiate among tissues. For example, dipoles in fats or
hydrocarbon rich
environments have much shorter T1 relaxation times than those in aqueous
environments.
Despite its increasing number of applications, MRI is impeded by its intrinsic
low
detection sensitivitP compared to imaging modalities that use ionizing
radiation such
as Positron Emission Tomography (PET), hampering its ability to detect certain
pathologies, such as small tumors or differentiating post therapy tumor
progression.
Governed by the thermal equilibrium polarization of the nuclei, e.g. at room
temperature
and magnetic field of 1.5 Tesla (T) (commonly used in most clinical MR
scanners), only
5 out of 1 million 1H spins are polarized9. According to Curie's Law,
macroscopic
magnetization is directly proportional to the magnetic field strength10.
Increasing the
field strength can partly compensates for this loss in sensitivity and improve
signal-to-
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CA 02805543 2013-02-12
noise ratio (S/N)11. However, other than the cost of ultrahigh field scanners
(higher than
7 T), there is a major concern relating to tissue overheating due to
overexposure of
radiofrequency12 and technical issues such as coil design13.
Currently, the widely applied method of increasing MRI SIN, hence contrast and
specificity, is the use of relaxation contrast agents, which can accelerate
the relaxation
rate of surrounding waters' nuclei spins. MR1 CAs are categorized into Ti and
T2 agents.
Ti agents are mainly based on paramagnetic metal ions with unpaired valence
electrons which can effectively shorten mainly the T1 relaxation time of the
nearby water
nuclei via electron-nuclear spin-spin coupling6. Clinical Ti CAs predominantly
utilize
Gd(III) which is chelated by different ligands to reduce the toxicity of free
Gd(III) in vivo.
Typical ligands include diethylene-triamine-penta-acetic acid (DTPA; Gd-DTPA
is sold
under the name Magnevist ) and 1,4,7,10-tetraazacyclododecane-1,4,7,10-
tetraacetic
acid (DOTA; Gd-DOTA is sold under the name Dotarem ) and their derivatives.
T2
agents, which are mostly superparamagnetic particles, disrupt the homogeneity
of the
magnetic field causing predominant decreases in T2 and 12* due to diffusion of
water
through field gradients. Ti agents are able to generate positive contrast
(increased
signal intensity) in T1 weighted images while T2 agents such as
superparamagnetic iron
oxide nanoparticles (SPIONs), generate negative contrast in T2 weighted
images. For
clinical diagnostic applications, T1 agents are usually preferred because a
number of
natural sources (tissues with low signal intensity) also generate negative
contrast,
complicating the analysis of the MRI image. In fact, most FDA approved 12
agents were
discontinued. Therefore the focus of this patent is on Ti agents.
A number of Gd-based CAs have been approved for clinical applications, such as
ProHance and Magnevist , which are currently dominating the CA market. At
least two
problems exist with small Gd-based CAs. The relaxivity of Gd-based contrast
agents
could be higher, particularly at high magnetic fields e.g., at 3 T or higher.
Further there
is a problem of toxicity that results from free Gd(III) i.e., which escapes
the chelating
agent in certain patients with renal dysfunction. These two issues are
interrelated.
Small Gd-based CAs have relatively low relaxivity (about 3-4 mtV1-1s-1 at 1 T,
37 C) and as a result, gram quantities are typically injected into a patient
for generating
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CA 02805543 2013-02-12
an image with reasonable quality. In recent years, MRI scanners are moving to
higher
magnetic fields (mainly 3 T) in order to perform scans with improved
signal/noise ratio,
shorter acquisition times and better image resolution. Since the relaxivity of
the
commercially available Gd-based CAs decreases at higher magnetic fields, even
larger
quantities of CAs would be required for adequate contrast enhancement14. In
addition,
studies such as contrast-enhanced MR angiography and delayed contrast-enhanced
myocardinal viability examinations require even higher CA doses and thus,
further
increase the risk of metal toxicity15. Although many in vitro studies have
indicated that
these Gd-based CAs are thermodynamically stable, the emergence and
proliferation of
nephrogenic systemic fibrosis (NSF) cases correlated to the usage of Gd-based
CAs
since the late 1990s suggests in vivo release and accumulation of toxic free
Gd(III) in
certain patients with renal dysfunction. Symptoms of NSF include severe skin
induration,
muscle restlessness and sometimes, physical disability. To address the
severity of this
safety issue, the FDA requires a "Black Box" warning label to be attached to
all Gd-
based CAs indicating possible adverse effects.
Various attempts have been made to improve the relaxivity mainly by Increasing
the size and thus rotational diffusion time (TR) of Gd-based CAs, based on the
Solomon-
Bloembergen-Morgan (SBM) theory. Common strategies include attachment of Gd
CAs
to proteins, dendrimers or polymers. Notably, at high magnetic fields (>1.5
T), the
electron spin relaxation of Gd(III) dominates the inner-sphere relaxivity,
therefore, the
strategy of increasing TR becomes much less efficient to improve ri for Gd-
based CAs at
high fields than low fields. Despite the moderate relaxivity increase, Gd
toxicity is likely
to persist In these macromolecular CAs16. In fact, because most of the
conjugation
chemistry involves the chelation sites, the Gd affinity will be lowered,
contributing to
higher risk of heavy metal leakage. In addition, the internal flexibility of
these aliphatic
dendrimers or polymers also contributed to the less than expected increase in
relaxivity
per Gd. Lastly, these large CAs are retained in the body for a longer period
of time,
leading to higher chance of Gd release than small Gd-based CAs.
There is thus a need to create a new generation of As that is more efficient
and
avoids the adverse effects of Gd toxicity. It will be desirable if the new
generation of
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CA 02805543 2013-02-12
CAs are free of toxic heavy metals such as Gd(III)and exhibit high
Tlrelaxivity at high
field.
SUMMARY
The invention includes a water soluble porphyrin compound of formula (A), or a
salt thereof:
\N N"--
\
NN'
/
G Ft' (A)
wherein one or more of D, E and F is defined as in paragraphs (a) to (c):
(a) (i) D is of the formula (LD):
=,. =
R \
\N \N
/
L0' \ /14\
04
N\ N N
Ft= / Wow N. Ra4
R. Dz (LD)
wherein:
each LD and LDI is independently a covalent bond or a rigid bivalent
linker;
one or the other or both of DI and D2 is a water-solubilizing group;
one or more of D3, D4 and Ds is a water-solubilizing group; and
mD has a value of from 0 to 20; or
(ii) D is of the formula (LW):
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CA 02805543 2013-02-12
Rss = l=
= 134
R,' N
IN====¨"Li¨ N I
/ I \
R??
.===,"
= it
-
Lo?
Rss "
RI3 X
/ I \
R,4
R. "
Lo\
Los
\ Ds
R. 23
4.47.44. N
433
-=5
FrP?
Los
Rs, " Dia
Rs? \
, ,,,r_N, ,
Rss Rss
Ds D,
(LD')
wherein:
LD is a rigid trivalent linker;
each LD1 is, independently of any other 1. 1, a covalent bond or a rigid
bivalent linker;
each LD2 is, independently of any other 1.1)2, a covalent bond or a rigid
bivalent linker;
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CA 02805543 2013-02-12
each 03 is, independently of any other L 3, a covalent bond or a rigid
bivalent linker;
each L 4 is, independently of any other 04, a covalent bond or a rigid
bivalent linker;
one or the other or both of D1 and D2 is a water-solubilizing group;
one or more of D3, D4 and D6 is a water-solubilizing group;
one or the other or both of D6 and DT is a water-solubilizing group;
one or more of 1)8, 03 and D1 is a water-solubilizing group;
MD1 has a value of from 0 to 20; and
mD2 has a value of from 0 to 20;
(b) (I) E is of the formula (LE):
1151
R R.+ R fta
N N N
\ NK / / \ N N X /
N
R . \I / Raft \I
R4e E, All R" El R" (LE)
wherein:
each LE and LE.' is, independently, a covalent bond or a rigid bivalent
linker;
one or the other or both of E1 and E2 is a water-solubilizing group;
one or more of E3, E4 and E3 is a water-solubilizing group;
mE has a value of from 0 to 20; or
(ii) E Is of the formula (LE'):
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CA 02805543 2013-02-12
E.
R63 / \
R.
N I
/ I \
LE2
fi*
mf R5
Fi15 \ = t2
I N I
/ \
R. R4,
R." R.
.""'" LE\ to
E,
Rez R11
-
E=
m" Is4
Fin "
Ro* N
R.15
I N N I
E0
R>, (LE')
wherein:
LE is a rigid trivalent linker;
each LEI is, independently of any other LEI, a covalent bond or a rigid
bivalent linker;
each LE2 is, independently of any other LE2, a covalent bond or a rigid
bivalent linker;
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CA 02805543 2013-02-12
each LE3 is, independently of any other Lc3, a covalent bond or a rigid
bivalent linker;
each LE4 is, independently of any other LE4, a covalent bond or a rigid
bivalent linker;
one or the other or both of El and E2 is a water-solubilizing group;
one or more of E3, E4 and E is a water-solubilizing group;
one or the other or both of E6 and E7 is a water-solubilizing group;
one or more of E8, E and El is a water-solubilizing group;
mEl has a value of from 0 to 20; and
mE2 has a value of from 0 to 20;
(c) (i) F is of the formula (LF):
Rtt F' /4 12.3 = t4
\ R" Ng,
\ N W====== \ N
IF
\ X /
X N N i+1 N
RI4R \ .0" / "
p p (LF)
wherein:
each LF and LFI is, independently, a covalent bond or a rigid bivalent
16 linker;
one or the other or both of Fl and F2 is a water-solubilizing group;
one or more of F3, F4 and F6 is a water-solubilizing group;
L" Is a covalent bond or a rigid bivalent linker; and
mE has a value of from 0 to 20; or
(ii) F is of the formula (IF'):
- 8 -
CA 02805543 2013-02-12
-.4 = oi
jr
Res / \
Roo
N I
/ I \
Rot RAI
1474 - /6
Fo
" Ro7 MTh
I N I
/ I \
Rio
fln
¨
X== = a
= 01
P
Roo
IN.===¨"M=¨= N I
/ I \
Re4
Roo
""=====.
= no
rrtz
R" N Po
Rol N
Re'
R,o2 Roo
Fo Fo
Ries Fttor (LF')
wherein:
LF is a rigid trivalent linker;
each LF1 is, independently of any other LFI, a covalent bond or a rigid
6 bivalent linker;
each LF2 is, independently of any other LF2, a covalent bond or a rigid
bivalent linker;
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CA 02805543 2013-02-12
each I-F3 is, independently of any other LF3, a covalent bond or a rigid
bivalent linker;
each LF4 is, independently of any other LF4, a covalent bond or a rigid
bivalent linker;
one or the other or both of F1 and F2 is a water-solubilizing group;
one or more of F3, F4 and F5 is a water-solubilizing group;
one or the other or both of Fe and F7 is a water-solubilizing group;
one or more of F8, F9 and F19 is a water-solubilizing group;
mF1 has a value of from 0 to 20; and
M F2
has a value of from 0 to 20; and wherein:
when D, E and F are all defined as in paragraphs (a) to (c), G is a water-
solubilizing
group, or G is defined as in paragraph (d):
(d) (i) G is of the formula (LG):
.õ, G. = 114
R \ RIOS " RIO
N N
( Le \ < L
N N N N
1
..õe R",,,
R1,0 R", R"0 60 Rim (LG)
wherein:
each L and 01 is, independently, a covalent bond or a rigid bivalent
liner;
one of the other or both of G1 and G2 is a water-solubilizing group;
one or more of G3, G4 and G5 is a water-solubilizing group;
LG1 is a covalent bond or a rigid bivalent linker; and
m has a value of from 0 to 20; or
(ii) G is of the formula (LG.):
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CA 02805543 2013-02-12
ri,
R112
I N I
\
mei R.
No. 1
N I
1
R
R" GI
113
G,
Fo$ N
.132
R. f
.132
171" ISA
R122 R4. Gio
Ro3 N
-
I N\ I
it I
RI$4 F1',0
Go
Ri3s Roe
wherein:
19 is a rigid trivalent linker;
each 191 is, independently of any other 191, a covalent bond or a rigid
bivalent linker;
each L.G2 is, independently of any other LG2, a covalent bond or a rigid
bivalent linker;
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CA 02805543 2013-02-12
each 03 is, independently of any other 03, a covalent bond or a rigid
bivalent linker;
each 04 is, independently of any other 04, a covalent bond or a rigid
bivalent linker;
one or the other or both of G1 and G2 is a water-solubilizing group;
one or more of G3, G4 and G5 is a water-solubilizing group;
one or the other or both of G6 and G7 is a water-solubilizing group;
one or more of G8, G6 and Gi is a water-solubilizing group;
mG1 has a value of from 0 to 20; and
mG2 has a value of from 0 to 20; and
the sum of m13, m1)1, mD2, mE, mEl, mE2, mF mF1, mF2, mG, -G1
m and IT1G2 is from 0 to 30;
and
M is a paramagnetic metal ion present in at least one porphyrin ring, and may
be the
same or different when present in a plurality of porphyrin rings.
In embodiments of a compound having formula (A), G can be a water-solubilizing
group selected from:
(I) carboxyl, sulfonate, phosphate (-0P03H2), alkylphosphate (-0P03R1-
1),
phosphonate (-P03H2), alkylphosphonate (-P03RH), phosphinate (-P02H),
alkylphosphinate (-P02R), amino, alkylamino (-NHR), dialkylamino (-NR2),
alkylammonium (-N R3), aminoalkyl (-(C1-C20 alkyl)NH2), guanidine
(-NHC(NH)NH2), alkyl guanidine (-NHC(NH)NRH), amido (-C(0)NH2, a C3-
C20 cycloalkyl group containing a nitrogen atom in its ring wherein the
cycloalkyl group is bonded to the porphyrin ring by a carbon or nitrogen
atom, a C3-C20 aryl group containing a nitrogen atom in its ring, and
OH
V
14,
OH
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CA 02805543 2013-02-12
wherein n is from 1 to 20;
C1-C20 alkyl substituted with one or more of sulfonate, phosphate (-0P031-12).
alkylphosphate (-0P03RH), phosphonate (-P03H2), alkylphosphonate
(-P03RH), phosphinate (-P021-J), alkylphosphinate (-P02R), amino,
alkylamino (-NHR), dialkylamino (-NR2), alkylammonium (-NR), aminoalkyl
(-(C1-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl guanidine
(-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted with up to 4
of any of hydroxyl, halogen, thiol, cyano, nitro, oxo (=CI);
C3-C20 cycloalkyl substituted with one or more of sulfonate, phosphate
(-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P03F12),
alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate
(-P02R), amino, alkylamino (-NHR), dialkylamino (-NR2), alkylammonium
(-NR3+), aminoalkyl (-(C1-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl
guanidine (-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted
with up to 4 of any of hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
C3-C20 heterocycloalkyl substituted with one or more of sulfonate, phosphate
(-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P03H2),
alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate
(-P02R), amino, alkylamino (-NHR), dialkylamino (-NR2), alkylammonium
(-NR3+), aminoalkyl (-(C1-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl
guanidine (-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted
with up to 4 of any of hydroxyl, halogen, thin!, cyano, nitro, oxo (=0);
alkenyl substituted with one or more of sulfonate, phosphate (-0P03H2),
alkylphosphate (-0P03RH), phosphonate (-P03H2), alkylphosphonate
(-P03RH), phosphinate (-P02H), alkylphosphinate (-P02R), amino,
alkylamino (-NHR), dialkylamino (-NR2), alkylammonium (-NR34), aminoalkyl
((C1-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl guanidine
(-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted with up to 4
of any of hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
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C3-C20 cycloalkenyl substituted with one or more of sulfonate, phosphate
(-0P03112), alkylphosphate (-0P03RH), phosphonate (-P031-12),
alkylphosphonate (-P03RH), phosphinate (-P021-1), alkylphosphinate
(-P02R), amino, alkylamino (-NHR), dialkylamino (-NR2), alkylammonium
(-NR3+), aminoalkyl (-(C1-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl
guanidine (-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted
with up to 4 of any of hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
C3-C20 heterocycloalkenyl substituted with one or more of sulfonate, phosphate
(-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P03H2),
alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate
(-P02R), amino, alkylamino (-NHR), dialkylamino (-NR2), alkylammonium
(-NR3+), aminoalky (-(C1-C20 alkyl)NH2)I, guanidine (-NHC(NH)NH2), alkyl
guanidine (-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted
with up to 4 of any of hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
Cg to C20 aryl substituted with one or more of sulfonate, phosphate (-0P03H2),
alkylphosphate (-0P03RH), phosphonate (-P03112), alkylphosphonate
(-P03RH), phosphinate (-P02H), alkylphosphinate (-P02R), amino,
alkylamino (-NHR), dialkylamino (-NR2), alkylammonium (-NR3+), aminoalkyl
(-(C1-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl guanidine
(-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted with up to 4
of any of hydroxyl, halogen, thiol, cyano, nitro;
C3 to C20 heteroaryl substituted with one or more of sulfonate, phosphate
(-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P03H2),
alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate
(-P02R), amino, alkylamino (-NHR), dialkylamino (-NR2), alkylammonium
(-NR3+), aminoalkyl (-(C1-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl
guanidine (-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted
with up to 4 of any of hydroxyl, halogen, thiol, cyano, nitro;
to C20 arylalkyl substituted with one or more of sulfonate, phosphate
(-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P031-12),
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CA 02805543 2013-02-12
alkylphosphonate (-P03R1-I), phosphinate (-P02H), alkylphosphinate
(-P02R), amino, alkylamino (-NHR), dialkylamino (-NR2), alkylammonium
(-NR), aminoalkyl (-(C1-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl
guanidine (-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted
with up to 4 of any of hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
C4 to C20 heteroaryialkyl substituted with one or more sulfonate, phosphate
(-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P03H2),
alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate
(-P02R), amino, alkylamino (-NHR), dialkylamino (-NR2), alkylammonium
(-NR34), aminoalkyl (-(C 4-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl
guanidine (-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted
with up to 4 of any of hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
C2 to C20 alkynyl substituted with one or more of sulfonate, phosphate
(-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P03112),
alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate
(-P02R), amino, alkylamino (-NHR), dialkylamino (-NR2), alkylammonium
(-NR3+), aminoalkyl (-(C1-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl
guanidine (-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted
with up to 4 of any of hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
C1 to C20 heteroalkyl substituted with one or more of sulfonate, phosphate
(-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P03112),
alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate
(-P02R), amino, alkylamino (-NHR), dialkylamino (-NR2), alkylammonium
(-NR3+), aminoalkyl (-(C1-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl
guanidine (-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted
with up to 4 of any of hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
C2 to C20 heteroalkenyl substituted with one or more of sulfonate, phosphate
(-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P03H2),
alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate
(-P02R), amino, alkylamino (-NHR), dialkylamino (-NR2), alkylammonium
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CA 02805543 2013-02-12
(-NR3+), aminoalkyl (-(C1-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl
guanidine (-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted
with up to 4 of any of hydroxyl, halogen, thiol, cyano, nitro, oxo (=0); and
C2 to C20 heteroalkynyl substituted with one or more of sulfonate, phosphate
(-0PO4-12), alkylphosphate (-0P03RH), phosphonate (-P03F12),
alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate
(-P02R), amino, alkylamino (-NHR), dialkylamino (-NR2), alkylammonium
(-NR3+), aminoalkyl (-(C1-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl
guanidine (-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted
with up to 4 of any of hydroxyl, halogen, thiol, cyano, nitro, oxo (=0),
wherein each R is independently straight or branched C1-C20 alkyl;
In such embodiments, one or more of i.e., at least one of D, E and F can be
defined as in foregoing paragraphs (a) to (c) in which:
(A) the one or the other or both of 01 and 02 that is a water-solubilizing
group is,
independently of the other, as defined in paragraph (I), and the other of D1
and
D2 is selected from the group consisting of:
(II) hydrogen;
C1-C20 alkyl optionally substituted with up to 4 of any of hydroxyl, halogen,
thiol, cyano, nitro, oxo (=0);
C3-C20 cycloalkyl optionally substituted with up to 4 of any of hydroxyl,
halogen, thiol, cyano, nitro, oxo (=0);
C3-C20 heterocycloalkyl optionally substituted with up to 4 of any of
hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
Ci-C20 alkenyl optionally substituted with up to 4 of any of hydroxyl,
halogen, thiol, cyano, nitro, oxo (=0);
C3-C20 cycloalkenyl optionally substituted with up to 4 of any of hydroxyl,
halogen, thiol, cyano, nitro, oxo (=0);
C3-C20 heterocycloalkenyi optionally substituted with up to 4 of any of
hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
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C6 to C20 aryl optionally substituted with up to 4 of any of hydroxyl,
halogen, thiol, cyano, nitro;
C3 to C20 heteroaryl optionally substituted with up to 4 of any of hydroxyl,
halogen, thiol, cyano, nitro;
C7 to C20 arylalkyl optionally substituted with up to 4 of any of hydroxyl,
halogen, thiol, cyano, nitro, oxo (=0);
C4 to 020 heteroarylalkyl optionally substituted with up to 4 of any of
hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
C2 to 020 alkynyl optionally substituted with up to 4 of any of hydroxyl,
halogen, thiol, cyano, nitro, oxo (=0);
C1 to 020 heteroalkyl optionally substituted with up to 4 of any of hydroxyl,
halogen, thiol, cyano, nitro, oxo (=0);
C2 to C20 heteroalkenyl optionally substituted with up to 4 of any of
hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
C2 to C20 heteroalkynyl optionally substituted with up to 4 of any of
hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
(B) the one or more of D3, D4 and D5 that is a water-solubilizing group is,
independently of the others, as defined in paragraph (I), and the other of D3,
D4
and D5 is, independently of the others, as defined in paragraph (II);
(C) the one or the other or both of D6 and D7 that is a water-solubilizing
group is,
independently of the other, as defined in paragraph (I), and the other of D6
and
D7 is, independently of the others, as defined in paragraph (II);
(D) the one or the other or both of El and E2 that is a water-solubilizing
group is,
independently of the other, as defined in paragraph (I), and the other of El
and
E2 is, independently of the others, as defined in paragraph (II);
(E) the one or more of E3, El and E5 that is a water-solubilizing group is,
independently of the others, as defined in paragraph (I), and the other of E3,
E4
and E5 is, independently of the others, as defined in paragraph (II);
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CA 02805543 2013-02-12
(F) the one or the other or both of E6 and E7 that is a water-solubilizing
group is,
independently of the other, as defined in paragraph (I), and the other of E6
and
E7 is, independently of the others, as defined in paragraph (II);
(G) the one or the other or both of F1 and F2 that is a water-solubilizing
group is,
independently of the other, as defined in paragraph (I), and the other of F1
and
F2 is, independently of the others, as defined in paragraph (II);
(H) the one or more of F3, F4 and F5 that is a water-solubilizing group is,
independently of the others, as defined in paragraph (I), and the other of F3,
F4
and F5 is, independently of the others, as defined in paragraph (II);
(I) the one or the other or both of F6 and F7 that is a water-solubilizing
group is,
independently of the other, as defined in paragraph (I), and the other of F6
and
F7 is, independently of the others, as defined in paragraph (II); and
the other(s) of said one or more of D, E and F can be as defined in paragraph
(I) or (II);
and
each of R1 to R107 can be, independently of the others, as defined in
paragraph (I) or
paragraph (II).
In particular embodiments, each said rigid bivalent linker is, independently,
selected from the group consisting of:
,
,
¨"X
3
/""14 , (X, - 0, S (X, V. Z 0,
or 1=111) s 20 wherein a said linker is
optionally substituted with one or more water-solubilising groups
and a said linker is optionally substituted with one or more of the
substituents defined by
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CA 02805543 2013-02-12
paragraph (II). It is preferred that the one or more water-solubilising groups
with which
such a linker is optionally substituted is selected from the group defined by
foregoing
paragraph (I).
In such embodiments, each of E and F can be, independently of the other, a
6 water-solubilizing group selected from:
carboxyl, sulfonate, phosphate (-0P03H2), alkylphosphate (-0P03RH),
phosphonate
(-P03H2), alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate
(-P02R), amino, alkylamino (-NHR), dialkylamino (-NR2), alkylammonium (-
NR31.),
aminoalkyl (-(C1-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl guanidine
(-NHC(NH)NRH), amido (-C(0)NH2, a C3-C20 cycloalkyl group containing a
nitrogen atom in its ring wherein the cycloalkyl group is bonded to the
porphyrin
ring by a carbon or nitrogen atom, a C3-C20 aryl group containing a nitrogen
atom
in its ring, and
0
o 0
0
OH
Oli
wherein n is from 1 to 20, and each R is independently straight or branched
Cl"
C20 alkyl; and
D can be of the formula (LD) wherein m has a value from 0 to 10.
According to particular embodiments of the compound, or a salt thereof, each L
and L 1 is a covalent bond,
, Or
=
each of D1, D2, D3, D- 5
, E, F and G is p-sulfonated phenyl or carboxyl;
each of R1 to R24 is H;
m is 8; and
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CA 02805543 2013-02-12
and M is manganese for each porphyrin ring.
In a particular embodiment of the compound, or a salt thereof, D is of the
formula
(LO);
mD = 0;
01 is:
/
each of D3, D4, 05, E, F and G is p-sulfonated phenyl;
each of R*1 to R8 and R17 to R24 is H; and
each M is manganese.
Other embodiments include a compound, or a salt thereof, wherein D, E, F and G
are as defined as in paragraphs (a) to (d) in which:
(aa) the one or the other or both of 01 and 02 that is a water-solubilizing
group is,
independently of the other, selected from the group consisting of:
(1) carboxyl, suifonate, phosphate (-0P03H2), alkylphosphate (-0P03RH),
phosphonate (-P03H2), alkylphosphonate (-P03RH), phosphinate
(-P021-0, alkylphosphinate (-P02R), amino, alkylamino (-NHR),
dialkylamino (-NR2), alkylammonium (-NR34), aminoalkyl (-(C1-C20
alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl guanidine
(-NHC(NH)NRH), amido (-C(0)NH2, a C3-C20 cycloalkyl group
containing a nitrogen atom in its ring wherein the cycloalkyl group is
bonded to the porphyrin ring by a carbon or nitrogen atom, a C3-C20
aryl group containing a nitrogen atom in its ring,
ptc_Lck,
.)1-1YH
0
0
Off
- 20 -
CA 02805543 2013-02-12
wherein n is from Ito 20;
C1-C20 alkyl substituted with one or more of sulfonate, phosphate
(-0P03H2), alkyiphosphate (-0P03RH), phosphonate (-P03H2),
alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate
(-MR), amino, alkylamino (-NHR), dialkylamino (-NR2), aminoalkyl
(-(Ci-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl guanidine
(-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted with up
to 4 of any of hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
C3-C20 cycloalkyl substituted with one or more of sulfonate, phosphate
(-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P03H2),
alkylphosphonate (-P03RH), phosphinate (-P021-1), alkylphosphinate
(-P02R), amino, alkylamino (-NHR), dialkylarnino (-NR2), aminoalkyl
(-(Ci-C20 alkyl)NH2), guanidine (-NHC(NH)NH2)1 alkyl guanidine
(-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted with up
to 4 of any of hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
C3-C20 heterocycloalkyl substituted with one or more of sulfonate,
phosphate (-0P03H2), alkylphosphate (-0P03RH), phosphonate
(-P03H2), alkylphosphonate (-P03RH), phosphinate (-P02H),
alkylphosphinate (-P02R), amino, alkylamino (-NHR), dialkylamino
(-NR2), aminoalkyl (-(C1-C20 alkyl)NH2), guanidine (-NHC(NH)NH2),
alkyl guanidine (-NHC(NH)NRH), amido (-C(0)NH2), and optionally
Substituted with up to 4 of any of hydroxyl, halogen, thiol, cyano, nitro,
oxo (=0);
C1-C20 alkenyl substituted with one or more of sulfonate, phosphate
(-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P03H2),
alkylphosphonate (-P03RH), phosphinate (-P021-0, alkylphosphinate
(-P02R), amino, alkylamino (-NHR), dialkylarnino (-NR2), aminoalkyl
(-(C1-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl guanidine
(-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted with up
to 4 of any of hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
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CA 02805543 2013-02-12
C3-C20 cycloalkenyl substituted with one or more of sulfonate, phosphate
(-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P031-12),
alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate
(-P02R), amino, alkylamino (-NHR), dialkylamino (-NR2), aminoalkyl
(-(C1-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl guanidine
(-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted with up
to 4 of any of hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
C3-C20 heterocycloalkenyi substituted with one or more of sulfonate,
phosphate (-0P03H2), alkylphosphate (-0P03RH), phosphonate
(-P03H2), alkylphosphonate (-P03RH), phosphinate (-P02H),
alkylphosphinate (-P02R), amino, alkylamino (-NHR), dialkylamino
(-NR2), aminoalkyl (-(C1-C20 alkyl)NH2), guanidine (-NHC(NH)NH2),
alkyl guanidine (-NHC(NH)NRH), amido (-C(0)NH2), and optionally
substituted with up to 4 of any of hydroxyl, halogen, thiol, cyano, nitro,
oxo (=0);
C6 to C20 aryl substituted with one or more of sulfonate, phosphate
(-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P03H2),
alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate
(-P02R), amino, alkylamino (-NHR), dialkylamino (-NR2), aminoalkyl
(4Ci-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl guanidine
(-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted with up
to 4 of any of hydroxyl, halogen, thiol, cyano, nitro;
C3 to C20 heteroaryl substituted with one or more of sulfonate, phosphate
(-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P03H2),
alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate
(-P02R), amino, alkylamino (-NHR), dialkylamino (-NR2), aminoalkyl
(-(C1-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl guanidine
(-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted with up
to 4 of any of hydroxyl, halogen, thiol, cyano, nitro;
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CA 02805543 2013-02-12
1
07 to 020 arylalkyl substituted with one or more of sulfonate, phosphate
(-0P03112), alkylphosphate (-0P03RH), phosphonate (-P03H2),
alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate
(-P02R), amino, alkylamino (-NHR), dialkylamino (-NR2), aminoalkyl
(-(C1-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl guanidine
(-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted with up
to 4 of any of hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
04 to 020 heteroarylalkyl substituted with one or more sultanate,
phosphate (-0P03H2), alkylphosphate (-0P03RH), phosphonate
(-P03H2), alkylphosphonate (-P03RH), phosphinate (-P021-1),
alkylphosphinate (-P02R), amino, alkylamino (-NHR), dialkylamino
(-NR2), aminoalkyl (-(C1-C20 alkyl)NH2), guanidine (-NHC(NH)NH2),
alkyl guanidine (-NHC(NH)NRH), amido (-C(0)NH2), and optionally
substituted with up to 4 of any of hydroxyl, halogen, thiol, cyano, nitro,
oxo (=0);
C2 to 020 alkynyl substituted with one or more of sulfonate, phosphate
(-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P03H2),
alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphwhinate
(-P02R), amino, alkylamino (-NHR), dialkylamino (-NR2), aminoalkyl
(-(01-C20 alkyONH2), guanidine (-NHC(NH)NH2), alkyl guanidine
(-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted with up
to 4 of any of hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
C1 to C20 heteroalkyl substituted with one or more of sulfonate, phosphate
(-0P03H2), alkylphosphate (-0P03RH), phosphonate
alkylphosphonate (-PO3RH), phosphinate (-P02H), alkylphosphinate
(-P02R), amino, alkylamino (-NHR), dialkylamino (-NR2), aminoalkyl
(-(01-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl guanidine
(-NHC(NH)NRH), amido (-C(0)NH2), and optionally substituted with up
to 4 of any of hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
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CA 02805543 2013-02-12
C2 to C20 heteroalkenyl substituted with one or more of sulfonate,
phosphate (-0P03H2), alkylphosphate (-0P03RH), phosphonate
(-P03H2), alkylphosphonate (-P03RH), phosphinate (-P02H),
alkylphosphinate (-P02R), amino, alkylamino (-NHR), dialkylamino
(-NR2), aminoalkyl (-(Ci-C20 alkyONH2), guanidine (-NHC(NH)NH2),
alkyl guanidine (-NHC(NH)NRH), amido (-C(0)NH2), and optionally
substituted with up to 4 of any of hydroxyl, halogen, thiol, cyano, nitro,
oxo (=0); and
C2 to C20 heteroalkynyl substituted with one or more of suffonate,
phosphate (-0P03H2), alkylphosphate (-0P03RH), phosphonate
(-P03H2), alkylphosphonate (-P03RH), phosphinate (-P02H),
alkylphosphinate (-P02R), amino, alkylamino (-NHR), dialkylamino
(-NR2), aminoalkyl (-(C1-C20 alkyl)NH2), guanidine (-NHC(NH)NH2),
alkyl guanidine (-NHC(NH)NRH), amido (-C(0)NH2), and optionally
substituted with up to 4 of any of hydroxyl, halogen, thiol, cyano, nitro,
oxo (=0),
wherein each R is independently straight or branched Ci-C20 alkyl;
(bb) the other of 01 and 02 is selected from the group consisting of:
(2) hydrogen;
Ci-C20 alkyl optionally substituted with up to 4 of any of hydroxyl, halogen,
thiol, cyano, nitro, oxo (=0);
C3-C20 cycloalkyl optionally substituted with up to 4 of any of hydroxyl,
halogen, thiol, cyano, nitro, oxo (=0);
C3-C20 heterocycloalkyl optionally substituted with up to 4 of any of
hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
Ci-C20 alkenyl optionally substituted with up to 4 of any of hydroxyl,
halogen, thiol, cyano, nitro, oxo (=0);
C3-C20 cycloalkenyl optionally substituted with up to 4 of any of hydroxyl,
halogen, thiol, cyano, nitro, oxo (=0);
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CA 02805543 2013-02-12
C3-C20 heterocycloalkenyl optionally substituted with up to 4 of any of
hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
Ce to C20 aryl optionally substituted with up to 4 of any of hydroxyl,
halogen, thiol, cyano, nitro;
C3 to C20 heteroaryl optionally substituted with up to 4 of any of hydroxyl,
halogen, thiol, cyano, nitro;
to C20 arylalkyl optionally substituted with up to 4 of any of hydroxyl,
halogen, thiol, cyano, nitro, oxo (=0);
C4 to C20 heteroarylalkyl optionally substituted with up to 4 of any of
hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
C2 to C20 alkynyl optionally substituted with up to 4 of any of hydroxyl,
halogen, thiol, cyano, nitro, oxo (=0);
C1 to C20 heteroalkyl optionally substituted with up to 4 of any of hydroxyl,
halogen, thiol, cyano, nitro, oxo (=0);
C2 to C20 heteroalkenyl optionally substituted with up to 4 of any of
hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
C2 to C20 heteroalkynyl optionally substituted with up to 4 of any of
hydroxyl, halogen, thiol, cyano, nitro, oxo (=0);
(cc) the one or more of D3, D4 and D5 that is a water-solubilizing group is,
independently of the others, as defined in paragraph (1), and the other of D3,
D4 and D5 is, independently of the others, as defined in paragraph (2);
(dd) the one or the other or both of De and 07 that is a water-solubilizing
group is,
independently of the other, as defined in paragraph (1)3 and the other of 06
and D7 is, independently of the others, as defined in paragraph (2);
26 (se) the one or the other or both of El and E2 that is a water-
solubilizing group is,
Independently of the other, as defined in paragraph (1), and the other of El
and E2 is, independently of the others, as defined in paragraph (2);
(if) the one or more of E3, E4 and E5 that is a water-solubilizing
group is,
independently of the others, as defined in paragraph (1), and the other of E3,
E4 and E5 is, independently of the others, as defined in paragraph (2);
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CA 02805543 2013-02-12
(gg) the one or the other or both of E6 and E7 that is a water-solubilizing
group is,
independently of the other, as defined in paragraph (1), and the other of E5
and E7 is, independently of the others, as defined in paragraph (2);
(hh) the one or the other or both of F1 and F2 that is a water-solubilizing
group is,
independently of the other, as defined in paragraph (1), and the other of FI
and F2 is, independently of the others, as defined in paragraph (2);
(ii) the one or more of F3, F4 and F5 that is a water-solubilizing
group is,
independently of the others, as defined in paragraph (1), and the other of F3,
F4 and F5 is, independently of the others, as defined in paragraph (2);
Up the one or the other or both of F6 and F7 that is a water-solubilizing
group is,
independently of the other, as defined in paragraph (1), and the other of F6
and F7 is, independently of the others, as defined in paragraph (2);
(10 the one or the other or both of GI and G2 that is a water-
solubilizing group is,
independently of the other, as defined in paragraph (1), and the other of GI
and G2 is, independently of the others, as defined in paragraph (2);
(II) the one or more of G3, G4 and G5 that is a water-solubilizing
group is,
Independently of the others, as defined in paragraph (1), and the other of G3,
G4 and G5 is, independently of the others, as defined in paragraph (2); and
(mm) the one or the other or both of G5 and G7 that is a water-solubilizing
group is,
independently of the other, as defined in paragraph (1), and the other of 56
and G7 is, independently of the others, as defined in paragraph (2), and
each of RI to R136 is, independently of the others, as defined in paragraph
(1) or
paragraph (2).
Preferred aspects of such embodiments are compounds or their salts, in which:
D is of the formula (LD'), E is of the formula (LE'), F is of the formula
(LP), G is of the
formula (LG');
DI 02 ... El E2 Fl F2 Gl G2 .
m - m - m rn mrn rn 1= n1 -0,
each of 02, 04, LE2, 04, LF2 LF4, LG2 and I.G4 is a covalent bond,
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CA 02805543 2013-02-12
, or
; and
each of D3, D4, D5, D8, D9, D10, E3, E4, E5, E8, E9, El , F3, F4, F5, F8, F9,
F19, G3, G4, G5,
G8, G9 and G19 is p-sulfonated phenyl or carboxyl
In a preferred aspect of the compound, or a salt thereof,each of LD, LE, LF
and LG
is:
IP
each of L02, 04, LE2, LE.4, LF2 LF4, L2 and LG4 is:
each of D3, D4, Ds, Da, De, Ea, E4õ Es, Ea, Ea,E10,Fa, F4, Fs, Fa,
Fe,F10Ga, G4, Gs,
G8, G9 and G19 is p-sulfonated phenyl;
each of RI to R8, R17 to R24, R33. to R40, R49 to R56, R65 to R72, RII3 to
R128 and RI29 to
R138 is H; and
each M is manganese.
A second broad aspect of the invention is a water soluble porphyrin compound
of
formula (A), or a salt thereof:
R.
N
F D
N
Ft4 \ Re
G IV (A)
wherein:
each of RI to R8 and D, E, F and G is independently selected from the group
consisting of:
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CA 02805543 2013-02-12
1
hydrogen, halogen, thiol, cyano, nitro, amido (-C(0)NH2), carboxyl, sulfonate,
phosphate (-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P03H2),
alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate (-P02R),
amino, alkylamino (-NHR), dialkylamino (-NR2), alkylammonium (-NR3+),
aminoalkyl (-(Ci-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl guanidine
(-NHC(NH)NRH), amido (-C(0)NH2, a C3-C20 cycloalkyl group containing a
nitrogen atom in its ring wherein the cycloalkyl group is bonded to the
porphyrin ring by a carbon or nitrogen atom, a C3-C20 aryl group containing a
nitrogen atom in its ring, and
0
w 0
0
H
0
wherein n is from 1 to 20;
C1-C20 alkyl, optionally substituted with up to 4 of any of hydroxyl,halogen,
thiol,
cyano, nitro, oxo (2=0), carboxyl, sulfonate, phosphate (-0P03112),
alkylphosphate (-0P03RH), phosphonate (-P03H2), alkylphosphonate
(-P03RH), phosphinate (-P02H), alkylphosphinate (-P02R), amino, alkylamino
(-NHR), dialkylamino (-NR2), aminoalkyl (-(C1-C20 alkyl)NH2), guanidine
(-NHC(NH)NH2), alkyl guanidine (-NHC(NH)NRH), amido (-C(0)NH2);
C3-C20 cycloalkyl, optionally substituted with up to 4 of any of
hydroxyl,halogen,
thiol, cyano, nitro, oxo (=0), carboxyl, sulfonate, phosphate (-0P031-12),
alkylphosphate (-0P03RH), phosphonate (-P03H2), alkylphosphonate
(-P03RH), phosphinate (-P02H), alkylphosphinate (-P02R), amino, alkylamino
(-NHR), dialkylamino (-NR2), aminoalkyl (-(C1-C20 alkyl)NH2), guanidine
(-NHC(N11)NH2), alkyl guankline (-NHC(NH)NRH), amido (-C(0)NH2);
C3-C20 heterooycloalkyl, optionally substituted with up to 4 of any of
26 hydroxyl,halogen, thiol, cyano, nitro, oxo (=0) , carboxyl,
sulfonate,
- 28 -
CA 02805543 2013-02-12
phosphate (-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P031-12),
alkylphosphonate (-P03RH), phosphinate (-P02H), alkyiphosphinate (-P02R),
amino, alkylamino (-NHR), dialkylamino (-NR2), aminoalkyl (-(C1-C20
alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl guanidine (-NHC(NH)NRH),
amido (-C(0)NH2);
C1-C20 alkenyl, optionally substituted with up to 4 of any of
hydroxyl,halogen,
thiol, cyano, nitro, oxo (=0) , carboxyl, sulfonate, phosphate (-0P03H2),
alkylphosphate (-0P03RH), phosphonate (-P03H2), alkylphosphonate
(-P03RH), phosphinate (-P02H), alkylphosphinate (-P02R), amino, alkylamino
(-NHR), dialkylamino (-NR2), aminoalkyl (-(C1-C20 alkyONH2), guanidine
(-NHC(NH)NH2), alkyl guanidine (-NHC(NH)NRH), amido (-C(0)N1-12);
C3-C20 cycloalkenyl, optionally substituted with up to 4 of any of
hydroxyl,halogen, thiol, cyano, nitro, oxo (=0) , carboxyl, sulfonate,
phosphate (-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P031-12)i
alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate (-P02R),
amino, alkylamino (-NHR), dialkylamino (-NR2), aminoalkyl (-(C1-C20
alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl guanidine (-NHC(NH)NRH),
amido (-C(0)NH2);
C3-C20 heterocycloalkenyl, optionally substituted with up to 4 of any of
hydroxyl,halogen, thiol, cyano, nitro, oxo (=0) , carboxyl, sulfonate,
phosphate (-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P03H2),
alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate (-P02R),
amino, alkylamino (-NHR), dialkylamino (-NR2), aminoalkyl (-(C1-C20
alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl guanidine (-NHC(NH)NRH),
amido (-C(0)NH2);
Ce to C20 aryl, optionally substituted with up to 4 of any of
hydroxyl,halogen, thiol,
cyano, nitro, carboxyl, sulfonate, phosphate (-0P03H2), alkylphosphate
(-0P03RH), phosphonate (-P03112), alkylphosphonate (-P03R1-1), phosphinate
(-P02H), alkylphosphinate (-P02R), amino, alkylamino (-NHR), dialkylamino
-29-
CA 02805543 2013-02-12
(-NR2), aminoalkyl (-(C1-C20 alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl
guanidine (-NHC(NH)NRH), amido (-C(0)NH2);
C3 to C20 heteroaryl, optionally substituted with up to 4 of any of
hydroxyl,halogen, thiol, cyano, nitro, carboxyl, sulfonate, phosphate
(-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P03H2),
alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate (-P02R),
amino, alkylamino (-NHR), dialkylamino (-NR2), aminoalkyl (-(C1-C2o
alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl guanidine (-NHC(NH)NRH),
amido (-C(0)NH2);
C7 to C20 arylalkyl, optionally substituted with up to 4 of any of
hydroxyl,halogen,
thiol, cyano, nitro, oxo (=0) , carboxyl, sulfonate, phosphate (-0P03H2),
alkylphosphate (-0P03RH), phosphonate (-P03112), alkylphosphonate
(-P03RH), phosphinate (-P02H), alkylphosphinate (-P02R), amino, alkylamino
(-NHR), dialkylamino (-NR2), aminoalkyl (-(C1-C20 eilkyONH2), guanidine
(-NHC(NH)NH2), alkyl guanidine (-NHC(NH)NRH), amido (-C(0)NH2);
C4 to C20 heteroarylalkyl, optionally substituted with up to 4 of any of
hydroxyl,halogen, thiol, cyano, nitro, oxo (=0) , carboxyl, sulfonate,
phosphate (-0P03H2), alkyiphosphate (-0P03RH), phosphonate (-P03112),
alkyiphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate (-P02R),
amino, alkylamino (-NHR), dialkylamino (-NR2), aminoalkyl (-(C1-C20
alkyONH2), guanidine (-NHC(NH)NH2), alkyl guanidine (-NHC(NH)NRH),
amido (-C(0)NH2):
C2 to C20 alkynyl, optionally substituted with up to 4 of any of
hydroxyl,halogen,
thiol, cyano, nitro, oxo (=0) , carboxyl, sultanate, phosphate (-0P03112),
alkylphosphate (-0P03RH), phosphonate (-P03H2), alkylphosphonate
(-P03RH), phosphinate (-P02H), alkylphosphinate (-P02R), amino, alkylarnino
(-NHR), dialkylamino (-NR2), aminoalkyl (-(C1-C20 alkyONH2), guanidine
(-NHC(NH)NH2), alkyl guanidine (-NHC(NH)NRH), amido (-c(0)N Ho;
Ci to 020 heteroalkyl, optionally substituted with up to 4 of any of
hydroxyl,halogen, thiol, cyano, nitro, oxo (0), carboxyl, sulfonate,
- 30 -
phosphate (-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P031-12),
alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate (-P02R),
amino, alkylamino (-NHR), dialkylamino (-NR2), aminoalkyl (-(C1-020
alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl guanidine (-NHC(NH)NRH),
amido (-C(0)NH2);
C2 to C20 heteroalkenyl, optionally substituted with up to 4 of any of
hydroxyl,halogen, thiol, cyano, nitro, oxo (=0), carboxyl, sulfonate,
phosphate
(-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P03H2),
alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate (-P02R),
amino, alkylamino (-NHR), dialkylamino (-NR2), aminoalkyl (-(C1-C20
alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl guanidine (-NHC(NH)NRH),
amido (-C(0)NH2); and
C2 to C20 heteroalkynyl, optionally substituted with up to 4 of any of
hydroxyl,halogen, thiol, cyano, nitro, oxo (=0) , carboxyl, sulfonate,
phosphate
(-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P031-12),
alkylphosphonate (-P03RH), phosphinate (-P02H), alkylphosphinate (-P02R),
amino, alkylamino (-NHR), dialkylamino (-NR2), aminoalkyl (-(C1-C20
alkyl)NH2), guanidine (-NHC(NH)NH2), alkyl guanidine (-NHC(NH)NRH),
amido (-C(0)NH2),
wherein each R is independently straight or branched C1-C20 alkyl,
wherein at least one of R1 to R8 and D, E, F and G is carboxyl, sulfonate,
phosphate
(-0P03H2), alkylphosphate (-0P03RH), phosphonate (-P03H2), alkylphosphonate
(-P03R1-1), phosphinate (-P02H), alkylphosphinate (-P02R), amino, alkylamino
(-NHR), dialkylamino (-NR2), aminoalkyl (-(C1-C20 alkyl)NH2), guanidine
(-NHC(NH)NH2), alkyl guanidine (-NHC(NH)NRH).
According to an embodiment, each of D, E, F and G is selected from the group
consisting of: carboxyl, sulfonate, phosphate (-0P03H2), alkylphosphate (-
0P03RH),
phosphonate (-P03H2), alkylphosphonate (-P03RH), phosphinate (-P02H),
alkylphosphinate
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CA 2805543 2019-10-15
CA 02805543 2013-02-12
(-P02R), amino, alkylamino (-NHR), dialkylamino (-NR2), alkylammonium
(-NR34)õ guanidine (-NHC(NH)NH2), alkyl guanidine (-NHC(NH)NRH), and
0
N co 11
...e"
OH 0 n
In preferred aspects,each of D, E, F and G is carboxyl, each of R1 to R8 is
hydrogen; and M is manganese. 1
Compounds and salts find use as CAs in MR1. in an aspect, the invention
includes a pharmaceutical formulation containing a compound or salt thereof,
as
described herein. Such a formulation includes a pharmaceutically acceptable
carrier,
wherein the formulation is suitable for administration as an imaging enhancing
agent
and the contrast agent is present in an amount sufficient to enhance a
magnetic
resonance image.
According to another aspect, the invention is a method of generating an image
of
at least a part of a subject. The method includes administering a compound or
salt
thereof, as described herein, to a subject, and generating an image of at
least a part of
said subject to which said compound has been distributed.
According to an embodiment, the invention includes a method of imaging a tumor
and surrounding tissue in a subject comprising administering to the subject a
composition comprising a compound or salt thereof, as described herein, and
imaging
the tumor and surrounding tissue in said subject.
The invention includes a composition containing a compound or salt thereof, as
described herein, and a pharmaceutically acceptable carrier, excipient or
diluent,
suitable for administration to a subject.
The invention is also a method for imaging a patient. The method includes
administering a composition comprising a compound or salt thereof, as
described herein,
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CA 02805543 2013-02-12
as a blood-pool imaging agent, and obtaining a magnetic resonance angiography
(MRA).
BRIEF DESCRIPTION OF DRAWINGS
Embodiments will now be described, by way of example only, reference being
made to the accompanying drawings, in which:
Figure 1 shows chemical structures of MnTCP, MnTPPS (prior art) and
(MnTPPS3)2.
Figure 2 shows NMRD of, in ascending order along the left-hand side of the
plots, (MnTPPS3)2, MnTCP, MnTPPS (prior art), and Gd-DTPA (prior art). T1
relaxivity
values were measured per Mn(III) or Gd(III) up to 1 T.
Figure 3 shows Ti weighted spin echo phantom images (TR = 122 ms, TE =
18.5 ms ) of Gd-DTPA, MnTCP, MnTPPS and (MnTPPS3)2 at 3 T and 25 C. (A) A
schematic diagram of how the solutions are placed. (B) The corresponding
phantom
Images produced by the 3 T scanner.
Figure 4 shows Ty-weighted spin-echo MR's at 31. A dose of 0.05mmo1 Mn/kg
of MnTCP, MnTPPS, and (MnTPPS3)2 was introduced into rats via tail vein
injection.
DETAILED DESCRIPTION
An embodiment of the invention is represented by a porphyrin compound of
formula (A), exemplified here by MnTCP:
E R2 c02-
\ R1
N N N
F / 10C /7\ CO r
N N N N
/
Re R7 co
(A) MnTCP
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CA 02805543 2013-02-12
In MnTCP, each of R1 to R8 of a compound of formula (A) is a hydrogen atom,
and each
of 0, E, F and G is a carboxyl group, shown in the ionized form for
convenience, and
the metal complexed by the porphyrin ring is manganese, which is Mn(111) in
the
exemplified embodiment, described below.
Another embodiment of the invention is represented by a porphyrin compound of
formula (A-LD) exemplified by (MnTPPS3)2:
-"
-R Ra R
N N Nr=¨=.
F /1,A\
N N
N\
R. \ / 72 / "R2
G R" R14 1122 133 R"
A-LD
S. . =
\ \
1 1
N N N"*"=
/\N 404 \ *
N N
SOr 10 (MnTPPS3)2
in (MnTPPS3)2, substituent 0 of compound A is LD in which mc) = 0 and I-D1 is
a
biphenyl group in which each phenyl group is para-substituted, each of R1 to
R8 and R17
to R24 is a hydrogen atom, and each of D3, D4, D5, E, F and G is a para-
sulfonated
phenyl group, shown in the ionized form for convenience, and the metal
complexed by
- 34-
CA 02805543 2013-02-12
each porphyrin ring is manganese, which is Mn(III) in the exemplified
embodiment,
described below.
Embodiments of the invention include compounds of formula (A) similar to
(MnTPPS3)2 in which aromatic rings of the linkers bear solubilising groups,
such as
sulfonate groups:
N N.¨ N N"'"'
411 SOr
= * \ /A\ 411
N N N\
1 1
SO,- so,
õ
N N "==== """
/N
-04 itA \ õA\ / SOr
N N N
101 401
SO,- SOr
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CA 02805543 2013-02-12
0 0
-.
\ N\ /r4.- \ N / N''''.
'W'N N \
N N
1
\ / 1
S03
110 1
,
,
so, sch
Another polyporphyrin related to (MnTPPS3)2, is one in which substituent 0 of
compound A is LD and LD and LD1 are biphenyl groups, m is from 1 to 30, each
of R1 to
R24 is a hydrogen atom, and each of Dl, D2, D3, D4, D5, E, F and G is a para-
sulfonated
phenyl group:
40 411/ 410
-,õ =-. \ -, --- \ -.
a lit \ i >1( / 0 0.
...._.=. " N N
1
\ ,./. /
11101 110 1110
so. so. .
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CA 02805543 2013-02-12
An embodiment of the invention is a compound of formula (A) in which
substituent D is LD and m = 0 and L 1 is a phenyl group linking porphyrin
rings by
through covalent bonds at para-positions, each of R1 to R24 is a hydrogen
atom, and
each of D3, D4, D5, E, F and G is a para-sulfonated phenyl group, shown in the
ionized
form for convenience, and the metal complexed by each porphyrin ring is
manganese,
which is Mn(III):
=
N N N N"--
\
" / 110 N" N 411
N N
11101
803. $O3
- 37 -
CA 02805543 2013-02-12
Another embodiment of the invention is a compound of formula (A) in which
substituent D is LD and MD :"-= 0 and L01 is a covalent bond, each of R1 to
R24 is a
hydrogen atom, and each of D3, D4, D5, E, F and G is a para-sulfonated phenyl
group,
shown in the ionized form for convenience, and the metal complexed by each
porphyrin
ring is manganese, which is Mn(III):
SO3
S.
\ \
\N N
N\ """==
\"
N N
S.
SO 3 SON
Another embodiment of the invention is (MnTCP)2:
cor co2-
N N N
-20C \ )A /Mkµ
Nf\ N
\ 40/ /
co CO2-
(NinTCP)2 is thus a compound of formula (A) in which substituent D is LD and m
= 0
and LD1 is a covalent bond linking mesa-positions of porphyrin rings, each of
R1 to R7
and R17 to R24 is a hydrogen atom, and each of D3, D4, D5, E, F and G is a
carboxyl
group, shown above in the ionized form for convenience, and the metal
complexed by
each porphyrin ring is manganese,
- 38-
CA 02805543 2013-02-12
A related polyporphyrin is one in which substituent D of compound A is LD and
L and L 1 are covalent linkages between meso-positions of porphyrin rings, m
is from
I to 30, each of R1 to R24 is a hydrogen atom, and each of DI, D2, D3, D4, D5,
E, F and
G is a carboxyl group:
CO2COr
\ N \ N N"'"` \ N\ /N
\
= \ 1,4s /14Q\ CO2
N N N N N
\ /
1
c(x coz co2
-39 -
CA 02805543 2013-02-12
Embodiments of the invention include polyporphyrins in which each of D, E, F
and G includes a porphyrin ring. In one such embodiment, D, E, F and G are LD,
LE, LF,
and LG, respectively in which m , mE, mF and mG are all equal to zero; each of
D3, D4,
D5, E3, E4, E5, F3, t" -4,
F5, G3, G4 and G5 is a para-sulfonated phenyl group; each of 01,
E1,
L LFI and LG1 is a biphenyl group; and all a-positions of the porphyrin
rings are
unsubstituted i.e., R1 to R8, R17 to R24, R49 to R58, R81 to R88, and R113 to
R12 are all
hydrogen atoms:
60,
N 44^=-
411
C
OPP
+4 N N N
\\. \
* 40 " \ SO>
N N
N
\ /
I NI
00
\
N N
"
N
110
NOI
- 40 -
CA 02805543 2013-02-12
In another such embodiment, in which each of D, E, F and G includes a
porphyrin ring, D, E, F and G are LD', LE', LF' and LG' wherein 171D1, mD2,
mE1, mE2, mF1,
mF2, m31 and mG2 are all equal to zero; each of 03, D4, D5, DB, D9, Dio, E3,
E4, E5, Es, E9,
Eio, F3, F4, F5, Fs, F9, F10, G3, G4, G5, u- =-=8, G9 and G18 is a para-
sulfonated phenyl group;
and all fl-positions of the porphyrin rings are unsubstituted i.e., R1 to R8,
R17 to R24, R33
to R40, R49 to R88, R88 to R72, R81 to R88, R97 to R184, R113 to R129 and R129
to R138 are all
hydrogen atoms:
S.' 0 a
ar
-Ca a
a
a=A'
4111W 11,
0111.1
's*
a
=== ". 0 a-
One can thus see that disclosed embodiments encompass monomeric, dimeric
and oligomeric porphyrins. In preferred embodiments, the molecules are free of
gadolinium, and M can be manganese, either Mn(II) or Mn(III), preferably
Mn(III). Useful
as contrast agents, compounds of the invention include substituent groups that
render
the compound soluble in water i.e., a biological medium provided by the human
body in
the context of clinical examinations, particularly, plasma, blood and
biological fluids.
Field-dependent-T-1 relaxivities of MnTCP and (MnTPPS3)2 were examined and
compared to known agents, IVInTPPS and Gd-DTPA. Chen at al. first reported the
relaxivity of MnIPPS at -0.5 1 (20 MHz)17, and Konieg and colleagues
subsequently
measured the T1 Nuclear Magnetic Resonance Dispersion (NMRD) profile (field-
dependent relaxivity) of this monomeric MnP18 and found that it exhibits
"anomalous
high relaxivity", considering there are only four unpaired electrons (S = 4/2)
in Mn(III)
relative to seven in Gd(III),
- 41 -
CA 02805543 2013-02-12
The relaxivity of MnTPPS peaks at 0.2 T at 37 C and plateaus at > 10 mhes"1 up
to 11.15 The rigidity of the porphyrin scaffold reduces internal rotation and
efficiently
lowers the rotational diffusion rate of the CM. The electron configuration of
the complex
is important to determining relaxivity. Since porphyrins have large conjugated
TT systems,
electronic properties at the paramagnetic center can be tuned by introducing
different
functional groups on the porphyrin ring. Structural modifications made
available by
approaches described herein, such as appending polar groups to the porphyrin
ring can
not only optimize the electronic properties but also be made to tune the CA's
pharmaco-
kinetics. Small and polar porphyrins can be used as extracellular fluid CAs
since they
tend to be cleared rapidly by the kidney. Large porphyrins that have
relatively high
relaxivity and longer retention times in the body can be used for targeted
imaging.
Porphyrin chelates can have extended applications such as PET imaging
(replacing
Mn(III) with a radioactive isotope 51Mn. Moreover, fluorescence imaging and
photo-
dynamic therapy (PDT) can be performed if diamagnetic versions, such as metal-
free or
16 Za(11) ¨inserted porphyrins are used19.
NMRD profiles were obtained to demonstrate continuous field-dependent T1
relaxivities. These were recorded using a field cycling NMR relaxometer
covering
magnetic fields from 0 to 1 T. As shown in Figure 2, compared to MnTPPS,
MnTCP,
and Gd-DTPA, the dimeric (MnTPPS3)2 exhibited the highest relaxivity per Mn at
fields
above ¨ 0.2 T. The relaxivity peak of (MnTPPS3)2 occurs close to 1 T and this
broad
peak extends to higher fields of 3 T and above, favoring high relaxivity at
high magnetic
fields. Although MnTCP displayed a lower relaxivity than MnTPPS at clinical
field
strengths, it was still found to be substantially higher than Gd-DTPA at
fields above 0.2
T.
26 Relaxivities of MnPs at 3 T were measured on a clinical MRI scanner
(Philips
Achieve). Each of the four CAs were prepared in a series of increasing
concentrations,
0, 0.05, 0.1, 0.2 and 0.5mM, and imaged using an inversion-recovery spin-echo
pulse
sequence with varied inversion times T1 and a multi-echo spin-echo sequence
with
varied echo times TE. As demonstrated in Figure 3, by comparison of samples at
the
same concentration, (MnTPPS3)2 shows the highest signal intensity on T1
weighted
-42-
CA 02805543 2013-02-12
images due to highest T1 relaxivity, and MnTCP exhibits significantly higher
relaxivity
than Gd-DTPA at 3 T. The ri values, listed in Table 1, also confirmed the high
efficacy
of MnPs at high field and increased high-field T. relaxivity per Mn with
increased
porphyrin size. The r1 values in Table 1 were derived by calculating Ti
relaxation times
from the inversion-recovery images and then linearly fitting the Ti relaxation
rates to
obtain the relaxivity ri. T2 relaxivities of the MnPs were also calculated and
are listed in
Table 1. The relatively weak T2 effect (negative contrast enhancement) does
not
significantly compromise positive contrast enhancement. Overall, in vitro
characterizations suggest that all MnPs are efficient Ti agents and useful for
high field
applications.
Table 1: Ti and T2 relaxivities for the Mn-Porphyrins
Porphyrin r1 (m1V1-1 s') r2 (mlµe s"1)
MnTCP 7.90 9.11
MnTPPS 8.63 10.4
(MnTPPS3).2 14.1 18.0
MnPs MnTCP and (MnTPPS3)2 were administrated in rats and submitted for MR1
studies on a 31 clinical scanner (Philips Achieve), with MnIPPS as a
reference, and
found to be efficient Ti CAs for in vivo applications, MnTCP and (MnIPPS3)2. A
relatively low dose, 0.05 mmol Mn/kg (typical dose for clinical Gd-based As is
¨ 0.1
.. mmol Gd/kg) was chosen based on the in vitro relaxivity values described
above. All
MnPs were found to exhibit significant Ti contrast enhancements in vivo after
intravenous injection, allowing the pharmacokinetic properties of MnPs,
including tissue
distribution, metabolic pathway and clearance rate to be analyzed from the in
vivo MRI
data.
As shown in the whole body images of the rats, Figure 4, the small and polar
MnTCP rapidly accumulated in the kidney within 10 minutes post injection and
the
majority of kidney enhancement was quickly relocated into the bladder within
an hour.
The desired rapid clearance of MnTCP via renal filtration was further
confirmed by urine
sample analysis. The characteristic reddish color of MnPs was clearly visible
by eye in
the urine samples. The concentrations of MnPs can be accurately quantified by
both
UV-vis and Mn atomic absorption (Mn AA) spectroscopic analyses. Very high
concen-
- 43 -
CA 02805543 2013-02-12
trations of Mn? were detected in urine 60 minutes (11.7 1,1M) after injection.
Absence of
MnTCP in urine sample collected about 24 h post injection suggested complete
clearance, similar to Gd-DTPA. In contrast, although MnTPPS showed similar
kidney Ti
enhancement 10 minutes post injection, the signal lasted significantly longer
than
MnTCP and was still visible in the image 1 day post-injection. In the same
image, the
clear liver enhancement suggested a dual-metabolic pathway through both
kidneys and
liver for MnTPPS, as reported in the literature25. The significantly slower
renal clearance
process of MnTPPS vs MnTCP was confirmed by urine sample analysis. The concen-
tration of MnTPPS 60 min post injection, was 4.41 j.tM in the urine sample,
lower than
that of MnTCP. Moreover, a significant amount of MnTPPS (1.12 uM) could still
be
detected in urine 24 hours post-injection. For the dimeric porphyrin,
(MnTPPS3)2, no
bladder enhancement was detected over the three days of the experimental
period.
Although accumulation was observed in the kidney, the dimer did not cross the
glomerulus and did not collect in urine on the tubular side. The exclusion of
the renal
metabolic pathway for (MnTPPS3)2 was further confirmed by urine sample
analysis. No
MnP signal was found by either Mn-AA or UV-vis in urine over the 72 hour post-
injection
period. The significant liver enhancement suggests that (MnTPPS3)2 was mainly
metabolized by the liver. Noticeably, (MnTPPS3)2 exhibited relatively long-
lasting
enhancement in the blood vessels and in the heart. Overall, these observations
demonstrated the feasibility of (MnTPPS3)2 as a blood-pool CA as well as a
tissue-
selective agent for liver imaging.
As Ti agents, polyporphyrins (two or more covalently linked porphyrin rings)
have
multiple paramagnetic centers per molecule, and have slower rotational
reorientation
rates (TR) to increase the T1 relaxivity, particularly at high magnetic fields
according to
the SBM theory. For in vivo applications, relatively low doses are needed,
reducing toxic
exposure of a subject. The size and geometry of a polyporphyrin can be
tailored to
adjust the pharmacokinetic properties, including diffusion rate, tissue
specificity and
metabolic pathway to match the different criteria for different applications,
such as
tissue-specific targeted imaging or dynamic contrast-enhanced (DCE) MRI.
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CA 02805543 2013-02-12
Monomeric water soluble porphyrins can be rapidly cleared through renal
filtration after in vivo administration, reducing the exposure time and thus
toxicity risk.
Monomeric orphyrins can be structurally modified to positively influence the
effect of
electron configuration on relaxivity. The optimized monomers can then be used
directly
for in vivo applications or as described herein as building blocks or
precursors to dimeric
and oligomeric porphyrins.
As indicated above, porphyrin compounds described herein are encompassed by
the family of compounds represented by formula (A):
R3 ER2
R4 R1
N\
F /M\
N
R6 0 (A)
Ring substituents D, E, F and G are covalently bonded to the mesa-positions of
the
porphyrin ring. The R-groups are covalently bound to the 3- and 4-positions of
pyrrole
groups of the porphyrin ring.
The compounds are water soluble, so contain at least one water-solubilizing
group. Water-solublizing groups of the invention render a compound suitably
soluble in
an aqueous medium for use as a CA agent.
Examples of water-solubilizing groups include the anionic groups carboxyl,
sulfonate, phosphate (-0P03H2), alkylphosphate (-0P03RH), phosphonate (-
P03H2),
alkylphosphonate (-P03R11), phosphinate (-P02H) and alkylphosphinate (-P02R).
The
alkyl group of the of an alkylphosphate or alkylphosphonate is typically a
straight chain
or branched C1-C10 alkyl group, e.g., methyl, ethyl, propyl, butyl, pentyl or
hexyl.
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CA 02805543 2013-02-12
Examples of water-solubilizing groups include the cationic groups amino,
alkylamino, dialkylamino, alkylammonium (-NR3+), aminoalkyl, guanidine
(-NHC(NH)NH2), alkyl guanidine (-NHC(NH)NRH), amido (-C(0)NH2, heterocyclic
cations. A heterocylic cation is a cycloalkyl or aryl group containing a
nitrogen atom in
its ring, e.g. alkyl pyridiums such as methyl pyridiniums:
CH
¨
b+ + ,
A porphyrin compound such as the MnTCP of the examples can include multiple
water-solubilizing groups. Such groups can be anionic, such as the carboxyl
group of
MnTCP, cationic, or can be a mixture of both, so that the compound can be
viewed as
zwitterionic. A carbon-based substituent e.g. alkyl containing a water-
solubilizing group
such as a carboxyl can also contain an amino group and thus also be
zwifterionic.
A water-solubizing group can also be a neutral hydrophilic group, which can be
instead of, or in addition to one or more ionic water-solubilizing groups.
Such groups
include polyols, polyethylene oxides (PEG), diethylene glycol (-
0CH2CH2OCH2CH2OH)
carbohydrates e.g., glucose, polysaccharides, dextrins, cylclodextrins, amino
sugar,
glucosamine, giucamine, their deravatives, and the following groups:
0 0
where n = 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,
or 20.
Water-solubilizing groups that are referred to as ionic are groups are charged
at
physiological pH. By "physiological pH" or "physiological conditions" is meant
water at a
pH of about 7.5 and about 37 C, and an ioinic strength of about 150 mM. Basic
groups,
such as amino groups that are converted to positively charged groups under
physio-
logical conditions, and acidic groups, such as carboxyl groups that exist as
negatively
-46 -
CA 02805543 2013-02-12
charged groups under physiological conditions are water-solubilizing groups.
Under
such conditions, at least 10%, but more preferably at least 20%, or at least
30%, or at
least 40%, or at least 50%, or at least 60%, or at least 70%, or at least 80%,
or at least
90%, or at least 96%, or at least 96%, or at least 97%, or at least 98%, or at
least 99%
of the water-solubilizing group exists in its charged Le. ionic form under
physiological
conditions. Such positively charged groups bearing a proton such as a
protonated
amino group (ammonium), have a pKa under such conditions that is less than
about 8.5.
More preferably, the pKa is less than 8, or less than 7.5, and more preferably
less than
7,0, more preferably still less than 6.5. Likewise, negatively charged groups
that are
unprotonated under physiological conditions, such as a carboxyl group
(carboxylate in
unprotonated form), have a plc, under such conditions that is less than about
8.5. More
preferably, the pKa is less than 8, or less than 7.5, and more preferably less
than 7.0,
more preferably still less than 6.6.
It is also to be understood that terms such as carboxyl encompass such groups
whether or not in ionized form as part of the compound, so cover salts Stich
as sodium
carboxyiate (-0O2"Na+), etc.
As describe elsewhere, in embodiments, carbon atoms of a polyporphyrin ring or
rings of a compound can bear one or more substituents have one or more
hydrogens replaced by e.g., an alkyl, aryl group, etc. When such a substituent
of a
polyporphyrin bears a water solubllising group such as an ionic or hydrophilic
group e.g.,
carboxyl or sulfonate, then the substituent is itself a water solubilising
group.
Of course, a monoporphyrin compound can also include one or more
substituents such as alkyl groups covalently linked to carbon atoms of the
porphyrin ring,
and these substituents can bear ionic or hydrophilic water-solubilizing
groups,
For use as an MRI agent, a compound is typically soluble in amount of between
10 pM to at least 1 M. Other minimum solubility ranges include from 0.0001 M
to 1 M,
0,001 M, 0.01 M to 1 M, 0.1 M to 1 M, or the minimum solubility could be at
least 0.0001
M, 0.001 M,0.01 M or 0.1.
The metal "M" is a paramagnetic metal ion, and includes Mn(II), Mn(III),
Fe(II),
Fe(III), Gd(III), Cu(I), Cu(II), Ni(II), Ni(I) and Ni(III). Advantageously,
the ion can be Mn(II)
-47-
CA 02805543 2013-02-12
and Mn(111), also referred to as Mn2+ and Mn3+, respectively, due to its
relatively low
toxicity. Mn(111) is preferred among the two oxidation states, due to the
higher stability. It
is possible for there to be more than one type of metal ion, paramagnetic or
diamagnetic
to be incorporated as part of a compound. At least one porphyrin ring of a
polyporphyrin
compound of the invention is metalated with paramagnetic ion, but it is
thought
preferable that all porphyrin rings of a polyporphyrin compound be metalated
for use as
an MR1 contrast agent.
Porphyrin substituents appended by covalent linkages to the porphyrin rings,
when specifically defined, are designated as R-groups, R1, R2, etc., and the
letters D, E,
F, G, D1, D2, etc. When so-defined, such substituents are monovalent radicals,
and it is
understood by the skilled person that such groups may be denoted for example
as "R"
or "-R". So a fluorine radical, for example, may be designated as "F" or "-F"
without
confusion.
An "alkyl" group indicates the radical obtained when one hydrogen atom is
removed from a hydrocarbon. An alkyl group has 1 to 20, 1 to 12, such as 1 to
6, 1 to 5,
1 to 4, 1 to 3, 1 or 2 carbon atoms, or 1 carbon atom. The term includes the
subclasses
normal alkyl (n-alkyl), secondary and tertiary alkyl, such as methyl, ethyl, n-
propyl,
isopropyl, n-butyl, isobutyl, sec.-butyl, tert.-butyl, pentyi, isopentyl,
hexyl and isohexyl.
A "cycloalkyl" group indicates a saturated cycloalkane radical having 3 to 20
.. carbon atoms, so can have 3 to 10 carbon atoms, in particular 3 to 8 carbon
atoms,
such as 3 to 6 carbon atoms, or 6 carbon atoms and includes fused monocyclic,
bicyclic, polycyclic, fused, bridged, or Spiro polycyclic ring structures, for
example,
cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, or cycloheptyl.
A "heterocydoalkyl" denotes a cycloalkane radical as described above in which
one or more CH2 groups atoms e.g., 1, 2, 3 or 4 CH2 groups are replaced by
corres-
ponding heteroatoms, 0 or S, or in which one or more CH groups are replaced by
a
corresponding heteroatom N, an example of which is piperazinyl.
An "alkenyl" group indicates an alkyl group in which 1, 2, 3, 4 or 5
unsaturations
(double bonds) replace a corresponding number of -CHCH- groups, examples being
ethenyl, propenyl, butenyl, pentenyl or hexenyl.
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CA 02805543 2013-02-12
A "cycloalkenyl" group indicates mono-, di- tri- or tetraunsaturated non-
aromatic
cyclic hydrocarbon radicals such as containing 3 to 20 carbon atoms, including
fused
monocyclic, bicyclic, polycyclic, fused, bridged, or spiro polycyclic ring
structures, and
include groups containing 3 to 10 carbon atoms, such as 3, 4, 5 or 6 carbon
atoms, e.g.
cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, cylcoheptenyl.
A "heterocycloalkenyl" indicates a cycloalkene radical (cycloalkenyl group) in
which one or more CH2 groups atoms e.g., 1, 2, 3 or 4 CH2 groups are replaced
by
corresponding heteroatoms, 0 or S, or in which one or more CH groups are
replaced by
a corresponding heteroatom N, examples being dihydrofuranyl and 2,5-dihydro-1H-
pyrrolyl.
An "aryl" group is a radical of aromatic carbocyclic rings having 6 to 20
carbon
atoms, such as 6 to 14 carbon atoms, or 6 to 10 carbon atoms, particularly 5-
or 6-
membered rings, that can be fused carbocyclic rings with at least one aromatic
ring,
such as phenyl, naphthyl, indenyl and indanyl.
A "heteroaryl" group is a radical containing at least one aromatic ring having
1 to
6 0, S and or N heteroatoms, and 1 to 20 carbon atoms, such as 1 to 5
heteroatoms
and 1 to 10 carbon atoms, or 1 to 5 heteroatoms and 1 to 6 carbon atoms, in
particular
5- or 6-membered rings with 1 to 4 heteroatoms, and can include fused bicyclic
rings
with 1 to 4 heteroatoms, and wherein at least one ring is aromatic, such as
pyridyl,
triazolyl, ouinolyl, isoquinolyl, indolyl, tetrazolyl, thiazolyl, imidazolyl,
pyrazolyl, oxazolyl,
isoxazolyl, thienyl, pyrazinyl, isothiazolyl, benzimidazolyi and benzofuranyl.
"Arylalkyl" denotes an aryl radical covalently joined to an alkyl group such
as a
benzyl group.
A "heteroarylalkyl" group indicates a heteroaryl radical covalently joined to
an
alkyl group.
An "alkynyl" group is a hydrocarbon radical having 1 to 5 triple C--C
bonds -CC-) and 2 to 20 carbon atoms, typically having 2 to 10 carbon atoms,
or 2 to 6
carbon atoms, such as 2 to 4 carbon atoms, examples being ethynyl, propynyl,
butynyi,
pentynyl or hexynyl.
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CA 02805543 2013-02-12
"Heteroalkyl, heteroalkenyl, heteroalkynyl" refer to alkyl, alkenyl and
alkynyl
groups, respectively, in which one or more of the carbon atoms (and any
associated
hydrogen atoms) are each independently replaced with the same or different
heteroatoms 0, S or N.
6 "Halogen" indicates a substituent from the seventh main group of the
periodic
table: fluoro, chloro, bromo and ioclo.
The term "haloalkyl" indicates an alkyl group substituted with one or more
halogen atoms as defined above, e.g. difluoromethyl. An alkyl optionally
substituted with
halogen is a haloalkyl when so substituted.
In general, an optional substitution with specified groups, radicals or
moieties
means that the subsequently described substitution may or may not occur, so
that the
description includes instances where the circumstance occurs and instances
where it
does not. An atom with unsatisfied valence(s) is assumed to have the hydrogen
atom(s)
to satisfy the valences.
*Phosphate" refers to a radical -0P(0)(OR)(OR") where R` and R" are each
independently hydrogen, alkyl, cycloalkyl, cycloheteroalkyl, aryl, arylalkyl,
heteroalkyl,
heteroaryl or heteroarylalkyl.
"Sulfonate" refers to a radical -S(0)(0)OR', where R' is hydrogen, alkyl,
cycloalkyl, cycloheteroalkyl, aryl, arylalkyl, heteroalkyl, heteroaryl or
heteroarylalkyl.
"Carboxy" or "carboxyl" means the radical -C(0)0H.
The term "hydroxyalkyr denotes an alkyl group substituted with one or more
hydroxyl groups such as hydroxymethyl, hydroxyethyl, hydroxypropyl.
An "alkoxy" group indicates a radical of the formula -OR' in which R' is alkyl
such
as methoxy, ethoxy, n-propoxy, isopropoxy, butoxy, etc.
The term "alkoxycarbonyl" indicates a radical of the formula -C(0)-0-R' in
which
R' is alkyl, such as methoxycarbonyl, ethoxycarbonyi, n-propoxycarbonyl,
isopropoxy-
carbonyl, etc.
The term "alkylcarbonyr indicates a radical of the formula -C(0)-R' in which
R' is
alkyl, such as acetyl.
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CA 02805543 2013-02-12
A "heterocyclic ring" includes heteroaryl, heterocycloalkyl and
heterocylcoalkenyl
and further includes annelated ring systems with each other or with cyclic
hydrocarbons.
The term "pharmaceutically acceptable salt" indicates salts formed by reacting
a
compound of formula (A) with a suitable inorganic or organic acid, such as
hydrochloric,
hydrobromic, hydroiodic, sulfuric, nitric, phosphoric, formic, acetic, 2,2-
dichloroaetic,
adipic, ascorbic, L-aspartic, L-glutamic, galactaric, lactic, maleic, L-malic,
phthalic, citric,
propionic, benzoic, glutaric, gluconic, D-glucuronic, methanesulfonic,
salicylic, succinic,
malonic, tartaric, benzenesulfonic, ethane-1,2-disulfonic, 2-hydroxy
ethanesulfonic acid,
toluenesulfonic, sulfamic or fumaric acid. Pharmaceutically acceptable salts
of
compounds of formula (A) may also be prepared by reaction with a suitable base
such
as sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium
hydroxide,
silver hydroxide, ammonia or the like, or suitable non-toxic amines, such as
lower
alkylamines, for example triethylamine, hydroxy-lower alkylamines, for example
2-
hydroxyethylamine, bis-(2-hydroxyethyl)-amine, glucamine, N-Methylglucamine
cycloalkylamines, for example dicyclohexylamine, or benzylamines, for example
NN-
dibenzylethylenediamine, and dibenzylamine, or L-arginine or L-lysine. Salts
obtained
by reaction with a suitable base include, but are not limited to sodium salts,
choline
salts, 2-(dimethylamino)-ethanol salts, 4-(2-hydroxyethyl)-morpholin salts, L-
lysine salts,
N-(2-hydroxyethyl)-pyrrolidine salts, ethanolamine salts, potassium salts,
tetrabutyl-
ammonium salts, benzyltrimethylammonium salts, cetyltrimethylammonium salts,
tetramethylammonium salts, tetrapropylammonium salts, tris(hydroxymethyl)amino-
methane salts, N-methyl-D-glucamine salts, silver salts, benzethonium salts,
and
triethanolamine salts.
According to various embodiments, a covalent linkage within a compound of
formula (A) is provided by, for example, Lip, where LD may be a covalent bond
or a
bivalent radical that provides the linkage. So here L is a "linker" that links
two groups
directly covalently as through a bond, or indirectly via a chemical moiety
i.e., bivalent
radical. Such a bivalent radical corresponds to a monovalent radical obtained
when a
hydrogen atom is removed therefrom. Where, for example, an aryl or cycloalkyl
group
provides such linkage and is therefore bivalent, the bivalent aryl or
cycloalkyl is referred
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CA 02805543 2013-02-12
to as "arylene" or "cycloalkylene", respectively. Examples of these respective
groups
are thus -C6H4- and -C6H10-, based on the phenyl and cyclohexyl groups. The
terms
"alkylene", "alkenylene", "heterocycloalkylene", "cycloalkenyiene",
"heterocyclo-
alkenylene", "heteroarylene", "arylalkylene", "heteroarylalkylene",
"alkynylene",
"haloalkylene" etc. are similarly derived terms. Other bivalent linkers are -X-
C(Y)- in
which X and Y are independently selected from the group 0, S and NH,
and -XC(Y)-2,- in which X, Y and Z are independently selected from the group
0, S and
NH.
According to various embodiments, a covalent linkage within a compound of
formula (A) by L where the linker covalently links three groups, as in the
moiety (ED'),
so the linker is a trivalent radical. Such a trivalent radical corresponds to
a bivalent
radical obtained when a hydrogen atom is removed therefrom, examples of which
are:
and
These linkers are referred to herein as "trivalent cyclohexyl" and "trivalent
phenyl"
groups, respectively, and other trivalent linkers are correspondingly termed.
Linkers, such as those illustrated above, can also bear water-solubilizing
groups.
It will thus be appreciated that a variety of water soluble porphyrin
compounds
useful as MR1 contrast agents are made available through this disclosure. In
addition to
monomeric porphyrins described herein, there are a number of polyporphyrins in
which
porphyrin rings are covalently linked to each other. As described in greater
detail
elsewhere herein, one general example is a diporphyrin in which porphyrin
rings are
directly covalently linked to each other through the meso-positions of the
peripheral
twenty carbon ring:
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CA 02805543 2013-02-12
N 14¨""" N
\ \
Here, for the sake of simplicity, substituents of porphyring rings are
omitted, be
they hydrogen atoms, water-solubilizing groups, etc. Porphyrin ring-
subsitutents can be
the same or different from ring to ring of a compound, as can be the
paramagnetic metal,
M.
Covalent linkage of porphyrin rings can also be provided by a covalent linker:
N N-- N\
./K \ X
N N N
\
Bivalent covalent linkers, illustrated above as the boxed 'V, are described in
greater detail elsewhere herein, Again, as for other polyporphyrins described
herein, it is
possible that porphyrin subsitutents be the same or different from ring to
ring of a
compound, as can be the paramagnetic metal, M.
Particular bivalent linkers include:
-CL, ¨d
s
or NIO S NEI)
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CA 02805543 2013-02-12
The linkers provide a rigid link between the porphyrin rings Le., have
relatively
high conformational rigidity and examples are aromatic ring(s), conjugated or
partially
conjugated (hyperconjugated) n-bond(s), or rigid systems with saturated bonds,
to
reduce internal motion.
A rigid linker covalently connects sites in the porphyrin rings, such as
carbon
atoms in meso-positions of neighboring porphyrin rings, so as to confine
movement of
those sites with respect to each other within the molecule. So, in aqueous
solution at
room temperature (21 C) two porphyrin rings directly connected to each other
by a
covalent bond between meso-carbons can rotate to some extent with respect to
the axis
defined by that bond, but the distance between those meso-carbons themselves
remains essentially unchanged. The degree to which such distance can vary is
possible
to determine by molecular modeling methods, such as molecular mechanics
calculation.
Two such covalently linked porphyrin rings, be it through a bond or linker
such as para-
carbons of phenyl ring (-C6114-), etc., are rigidly linked if the distance
between the linking
sites does not vary significantly due to conformational changes.
Polyporphyrins can have more than two porphyrin rings c,ovalently linked:
N N-""" N N-- N
rs
\ A / A / \
N N N N n N\
\ I \ \
Here, the linker can instead be a covalent bond, and such linkages can be
different between rings so that a compound includes different linkers between
porphyrin
rings, and/or covalent bonds acting as linkages. The number "n" in the
foregoing is a
whole number used to designate the number of porphyrin rings between the end
rings.
Various values of n, i.e., 0, 1, 2, 3 ... etc. are described in greater detail
elsewhere
herein.
Other arrangements of porphyrin rings are possible, such as:
- 54 -
CA 02805543 2013-02-12
/1\
N N
,00#
N\ /N NN N
\Aim\ \
N N
\
111
N
\ .0/
In such configuration, one, two, three or all of the four external porphyrins
can
have additional porphyrin rings covalently appended thereto as described
immediately
above. It is also possible that any one of the above-illustrated porphyrin
rings be omitted
to obtain a configuration in which three porphyrin rings are coviently linked
to three
meso-positions of a single porphyrin ring, again such linkages being provided
by any
combination or bivalent linkers or direct covalent bonds. Two of the
illustrated porphyrin
rings in neighboring positions can be omitted such that a porphyrin ring is
linked to a
pair of porphyrins through neighboring or vicinal meso-positions of its
peripheral carbon
ring. Additional porphyrin rings can be appended to one or more meso-positions
of the
illustrated porphyrins. In the foregoing example of a polyporphyrin, the
porphyring ring
bound to four porphyrins does not necessarily bear a water-solubilizing group.
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CA 02805543 2013-02-12
Additionally, neighboring porphyrin rings in a compound can be linked by a
trivalent linker:
N\ \/M\/
1
N
tkr
\ 1
N. N
Again, one, two or all three of the illustrated porphyrin rings can further
have
additional porphyrin ring(s) covalently appended thereto as described for the
above-
illustrated configurations.
The foregoing examples illustrate polyporphyrin compounds in which all the
porphyrin rings are shown as being metalated i.e., containing a paramagnetic
metal ion
"M". It is possible for one to all of the porphyrin rings to be metalated.
Bivalent and trivalent linkers themselves can bear one or more water-
solubilizing
groups as well as other substituents.
Compounds of the invention are particularly useful as CAs at relatively high
magnetic fields, for example at 1 -I or higher, 1.5 T or higher, 3 T or
higher, 4.31 or
higher, 7 T or higher, 9.4 T or higher, 11.7 T or higher, and up to 21 T.
As described above, particular compounds exhibit ri above 4 mrvtl s' at IT or
higher fields.
The present invention provides CAs that can be used to generate an image of a
human or non-human subject involving administering the contrast agent to the
subject
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CA 02805543 2013-02-12
e.g., vascularly, via the gastrointestinal tract, etc. and generating an image
of at least a
part of the subject to which the contrast agent has been distributed.
Known methods for administering diagnostics can be used to administer CAs.
For example, fluids that include pharmaceutically and physiologically
acceptable fluids,
including water, physiological saline, balanced salt solutions, buffers,
aqueous dextrose,
glycerol or the like as a vehicle, can be administered by any method used by
those
skilled in the art. These solutions are typically sterile and generally free
of undesirable
matter. The compositions may contain pharmaceutically acceptable auxiliary
substances as required to approximate physiological conditions such as pH
adjusting
and buffering agents, toxicity adjusting agents and the like, for example,
sodium acetate,
sodium chloride, potassium chloride, calcium chloride, sodium lactate and the
like. The
concentration of active agent in these formulations can vary widely, and will
be selected
primarily based on fluid volumes, viscosities, body weight and the like in
accordance
with the particular mode of administration and imaging modality selected. The
invention
16 further provides formulations comprising CA and a pharmaceutically
acceptable
excipient, wherein the CA is formed according to any of the embodiments
described
herein, and wherein the formulation is suitable for administration as an
imaging
enhancing agent and the CA is present in an amount sufficient to enhance an
MRI
image. These agents can be administered by any means in any appropriate
formulation.
Detergents can also be used to stabilize the composition or the increase or
decrease
the absorption of the composition. Other physiologically acceptable compounds
include
Wetting agents, emulsifying agents, dispersing agents or preservatives that
are
particularly useful for preventing the growth or action of microorganisms. One
skilled in
the art would appreciate that the choice of acceptable carrier, including a
physiologically
a acceptable compound depends, e.g. on the route of administration and on
the particular
physio-chemical characteristics of any co-administered agent.
Methods of introduction include, but are not limited to, intradermal,
intramuscular,
intraperitoneal, intravenous, subcutaneous, intranasal, rectal, vaginal, and
oral routes. A
CA composition may be administered by any convenient route, for example by
infusion
or bolus injection, by absorption through epithelial or mucocutaneous linings
e.g., oral
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CA 02805543 2013-02-12
mucosa, vaginal, rectal and intestinal mucosa, etc., and may be administered
together
with other biologically active agents. Administration can be systemic or
local. In addition,
a CA composition may be introduced into the central nervous system by any
suitable
route, including intraventricular and intrathecal injection; intraventricular
injection may
be facilitated by an intraventricular catheter, for example, attached to a
reservoir, such
as an Ommaya reservoir. A CA composition can be delivered by any means known
in
the art systematically e.g., intra-venously, regionally or locally e.g. intra-
or pad-tumoral
or intra-cystic injection, e.g. to image bladder cancer by e.g., intra-
arterial, intra-tumoral,
intra-venous, parenteral, intra-pneural cavity, etc. For example, intra-
arterial injections
can be used to have a regional effect e.g. to focus on a specific organ (e.g.
brain, liver,
spleen, lungs), For example intra-hepatic artery injection or intra-carotid
artery injection
may be used. If it is decided to deliver the preparation to the brain, it can
be injected into
a carotid artery or an artery of the carotid system of arteries e.g., ocipital
artery,
auricular artery, temporal artery, cerebral artery, maxillary artery, etc. The
present
invention includes pharmaceutical compositions which include a CA alone or
with a
pharmaceutically acceptable carrier.
An embodiment of the invention is a method of detecting a condition in which
cells express a characteristic surface protein. The method includes
administering to the
cells a CA comprising a compound of the invention that is coupled to an agent
which
binds to the protein, and obtaining an MRI image of the cells. The condition
can be a
lung disease, emphysema, asthma, a cancer, particularly breast, prostate, or
brain
cancer, ischemia, particularly stroke, cardiac infarct, muscle ischemia,
chronic kidney
disease, or liver disease, particularly cirrhosis or cancer of the liver.
Administering the
CA to cells can be in vivo or in vitro.
The invention is also a method for monitoring transport of an effector agent
to a
target found within a cell. This aspect includes contacting the cell with a
delivery vehicle
encapsulating the agent and a CA described herein, and obtaining an Mill image
of the
cell. The delivery vehicle can be a nanoparticle, a nanocapsule or a liposome.
The invention is also a method of labeling a cell. The method includes
administering to the cell a CA comprising a compound of the invention coupled
to an
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CA 02805543 2013-02-12
agent which binds to cell. The method can further include detecting the
labeled cell by
obtaining an MRI image thereof. The agent can be an antibody.
The invention includes amethod of screening for therapeutic agents useful in
the
treatment of a disease. This can include contacting a molecule comprising a
test
compound coupled to a CA disclosed herein and contacting the molecule with a
target
cell, and detecting the labeled cell by obtaining an MRI image thereof.
A CA and agent that includes coating material may be made up of, for example,
nanoparticles or nanocapsules, liposomes and the like. A suitable means is the
encap-
sulation in biodegradable polymers with controllable release, such as
polylactide and/or
polyglyoolide. In this context, the coating material may be chosen such that
the agent is
released in a predetermined manner. Such coating materials have been described
in
the literature and the skilled worker can select, from a multiplicity of
materials, the
material best suited to the purpose in hand.
The agent and CA are encapsulated with the encapsulation material, or coated
therewith, in a known manner. Encapsulation means that the agent is shielded
by the
polymer from the physiological environment, such that it is not altered or
degraded until
It arrives at the target. The encapsulation may be only one layer which
surrounds the
CA and agent, but it may also be a liposome or nanoparticle or microparticle
in which
the agent is embedded or enclosed. It may also be enclosed by complexing. A CA
and
agent may be covalently coupled to each other prior to encapsulation. A person
skilled
in the art is familiar with various forms of encapsulation or coating of
agents, which can
be employed as long as they do not interfere with the binding of e.g., the
target-finding
agent to its receptor and the introduction of the agent into the cell, and
release the
agent in the cell. The encapsulation of the agent with the encapsulation
material, and/or
the preparation of suitable particles, can be done using customary methods. In
the
simplest embodiment, the active agent is mixed with the encapsulation
material, for
example a cationic polymer, such as polyethyleneimine, if appropriate in
dissolved form.
Liposomes may comprise a lipid such as phosphatidylcholines (lecithins) (PC),
phosphatidylethanolamines (PE), lysolecithins, lysophosphatidylethanolamines,
phosphatidylserines (PS), phosphatidylglycerols (PG), phosphatidylinositol
(PI),
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CA 02805543 2013-02-12
sphingomyelins, cardiolipin, phosphatidic acids (PA), fatty acids,
gangliosicles,
glucolipids, glycolipids, mono-, di or triglycerides, ceramides, cerebrosides
and
combinations thereof; a cationic lipid (or other cationic amphiphile) such as
1,2-
dioleyloxy-3-(trimethylamino)propane (DOTAP); N-cholesteryloxycarbary1-3,7,12-
triaza-
pentadecane-1,15-diamine (CTAP); N41-(2,3,-ditetradecyloxy)propyll-N,N-
dimethyl-N-
hydroxyethylamm- onium bromide (DMRIE); N41-(2,3,-dioleyloxy)propyll-N,N-
dimethyl-
N-hydroxy ethylammonium bromide (DOME); N41-(2,3-dioleyloxy)propyll-N,N,N-
trimethylammonium chloride (DOTMA); 3 beta [N-(N',Nt-dimethylaminoethane)
carbamolylcholesterol (DC-Choi); and dimethyldioctadecylammonium (DDAB);
dioleoylphosphatidyl ethanolamine (DOPE), cholesterol-containing DOPC; and
combinations thereof; and/or a hydrophilic polymer such as
polyvinylpyrrolidone,
polyvinylmethylether, polymethyloxazoline, polyethyloxazoline,
polyhydroxypropyl-
oxazoline, polyhydroxypropylmethacrylamide, polymethacrylamide, polydimethyl-
acrylamide, polyhydroxypropylmethacrylate, polyhydroxyethylacrylate,
hydroxylmethyl-
cellulose, hydroxyethylcellulose, polyethyleneglycol, polyaspartamide and
combinations
thereof.
EXAMPLES
In general, monomeric porphyrins can be synthesized based on the Lindsey
method2 from pyrrole and the corresponding aldehydes. Monomers can then be
used
directly, or after necessary functional group transformations, to build
dimeric, oilgomeric
or polymeric porphyrins using coupling reactions. After installation of water
solubilizing
groups, paramagnetic ions e.g., manganese ions are inserted into the porphyrin
cores
to generate the final products. The sequence of these reaction steps can be
varied in
certain cases. Examples for reaction steps are described below.
Synthesis of Porphyrin Building Blocks
Using different compositions of aldehydes and pyrrole, different porphyrin
monomers can be obtained by a Lindsey reaction20, as exemplified in Scheme 1.
Both
symmetric (Ri = R2 = R3 = R4) or non-symmetric (at least two R groups are
different)
porphyrins can be obtained.
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CA 02805543 2013-02-12
R2
\
0
N a) Lindsey rxn \ NHN"--
RAH + '17 R\ / R3
N HN
R4
Scheme 1: General method for synthesis of symmetric or non-symmetric porphyrin
monomers.
For certain porphyrin building blocks, protection or functional group trans-
formation is necessary before they can be coupled together. Two examples are
shown
in Scheme 2, including protection of the porphyrin core by zinc insertion and
bromination on the porphyrin mesa-position.
=
100
\ NH N¨ N
b) ZnpAct2
111
r CAW
\ I \
1 Zn-f
= 110 110
\ \
\ NH N¨ MS \ NH N¨ b)Zn(00µ0)2 N \
\ H _________________ Br * /26\ ;
N HN N HN DMF N N
\ 1 /
\
\
011 40 40
2 3 2n-3
Scheme 2: Zinc insertion and bromination of porphyrins.
Coupling of Porphyrins
In principle, coupling chemistry can be applied to porphyrin building blocks
with
complimentary functional groups. Scheme 3 shows examples of three different
coupling
reactions, including oxidative coupling reaction with hypervalent iodine,
Suzuki coupling,
and Pd(II)-catalyzed homolytic coupling that could be applied for linking
porphyrin rings.
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CA 02805543 2013-02-12
(A)
Ra 82 R2 83 R R 83 82
\ R, R, Rs% -=== 83
N Pre \ N /N a) PWA =¨ \
\ 2 \ / \ / 812
N N N N N 14
/ RI fts \ / R3R3 / 14,,
R. R. Rs, RN Re Re R. R. Rs
4 8
(B)
82 8, R, Re 82 82 83 83 R R Rf 82
Rs ss tee, \ R, Re / Rf Rs
/ \ el er¨ N = * elõ,
e \ p4" R12 b) Suzuki Coupling R
\ N b Br / 0 12 \ ;10/s, \ RA I
RI2
N N N N t4/ Nel
RI, \ / 87 8, \ t / 8,, RI, \ eNs j / 8,
83 \ / RI
RR Rs Re R* Re Rio 8,0 - R.R Ro Rio
6 4-Br 7
(C)
83 R. Re 8, 8, 8, R, R. 82
RI Rs Rõ R,
\ /N c) IBA F N N N \
8.N/1% / = tE(0 X 2 _____ RI2 \ io A ,
N N N N
\ 143 8,, \ I / Ri 87
RI, Re Re Rs, Re Rs Ro Rio
8
Scheme 3: coupling reactions for the synthesis of porphyrin aligomers.
a)PhI(OCO-
CF3)2 (PIFA), b) Suzuki coupling: 2:1 Tol:DMF, Cs2CO3, Pd(PPh3)4, c) Tetra-n-
butylammonium fluoride (TBAF), Pd(PPh3)2Cl2, THF:H20 4:12 air, RT
Installation of Water Solubillzing Groups and Mn-Insertion
The final MnPs should be water-soluble for in vivo applications. The polar and
water-solubilizing groups, such as sulfonates or carboxylates can be
introduced by
different methods. By sulfonation reaction with concentrated sulfuric acid,
the sulfonates
can be installed on the phenyl groups attached to the porphyrin mesa-position;
the
carboxylate groups can be generated from the hydrolysis of ester groups pre-
installed
on the porphyrins. Mn can be inserted into the porphyrins, either before or
after the
introduction of water-solubilizing groups, as exemplified in Scheme 4.
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CA 02805543 2013-02-12
503- 803'
NH N - N H
IIEM N HN aI "12S 4 N N Link
\ 11 803
N HN NH N N HN NH N
N ,
1111
9
sr03- 903-
S03- 903-
N N õN
b) Mn(0A02 -03S =, Mn. , Mn$03-
N N
110
503- SO3-
Mn-10
0 = R 0 OR 0 a
RO NH N ________ 0 b) Mna2 RO N õ-N C) HydrOlysis '0 0
iriln
0 N NH OR 0 N OR
RO 0 RO 0 '0 0
11 Mn-11 12: MnTCP
Scheme 4 Examples of introducing sulfonates or carboxylates, and the insertion
of Mn
in porphyrins. a) Sulfonation: conc. H2S0480 C, 9h; b) Mn insertion:
lvin(0Ac)2 or
MnC12, DMF, reflux c) 2 M NaOH, THF, Et0H, reflux, 12 h
5 Synthetic Procedures
All reagents and solvents were of commercial reagent grade and were used
without further purification except where noted. 1H NMR spectra were performed
at 500
MHz. Mass spectra were obtained on electron-spray ionization mode. UV-vis
spectra
were recorded on an Agilent 8453 UV-Visible Spectroscopy Systems. Column
10 Chromatography was carried out using Caledon Silica Gel 60; 50-200
microns 70-300
mesh, or using Sephadex TM LH-20 with dry bead size of 18-111 pm from GE
Health
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CA 02805543 2013-02-12
Care Dialysis was performed with Sigma Aldrich Pur-A-LyzerTM Mega 3500/1000
MWCO. Reverse Phase column was loaded with Agela Technologies C18 Flash 40-60
pm. Cation ion exchange was performed using an Amberlite IR120, H resin,
(a) Synthesis of porphyrin 121
2.31 g (9.9 mmol) of 4-boronopinacolbenzaldehyde was added to a RB flask. 3.0
ml (30
mmol) of benzaldehyde was then added followed by 400 ml of anhydrous
dichloromethane. The flask was sealed and N2 was bubbled through for 20 min.
2.79 ml
(40.2 mmol) of freshly distilled pyrrole was added together with 0.63 ml of
BF3.0Et2
(12.4 mM). After 1 h of reflux in the dark, 7.94 g (35 mmol) of DDQ was added
and the
reaction was allowed to reflux for another 1 h. The solution was filtered with
basic
alumina and column chromatography with 6:4 dichloromethane-hexane solvent
system
was run through silica to remove TPP. The solvent was switched to 8:2 dichloro-
methane-hexane to elute the product. The product (30mg) was isolated with 4%
yield,
characterized by NMR and MS. 1H NMR (500 MHz, CDCI3): 6 8.84 (8H, s, por-11),
8.18-
8.25 (10H, m, Ph), 7.72-7.78 (9H, m, Ph), 1.50 (12H, s, alkyl), -2.78 (2H, s,
NH). ES!
MS found m/z = 741.3 ([M+Hr), calcd for C30H42BN.402+, m/z = 741.3.
(b) Synthesis of porphyrin (TPP)222.
73.6 mg (1 eqv) of 1, 9.0 mg of Pd(PPh3)2Cl2(0.1 eqv), 35 mg of
tetrabutylammonium
fluoride (leqv), were added to a pear shaped flask. 10 ml of 2:8 water and THF
solvent
mixture was added and allowed to stir at room temperature and opened to
oxygen. After
5.5 h, the reaction was stopped and dried by rotavap. The product is barely
soluble in
chloroform and diethyl ether, thus hexane:chloroform 7:3 and diethyl ether
were used to
rinse off porphyrin impurities. Filtration was performed and the purple
crystals residue
were rinsed with cold CHCI3. 48.5 mg of product was obtained (80 %). 1H NMR
(500
MHz, CDCI3): 6 9.06 (4H, d, J = 4.7 Hz, por-11), 8.94 (4H, d, J = 4.7 hz, por-
11), 8.88 (8H,
s, por-(1), 8.47 (4H, d, J = 8.1 Hz, Ph), 8. 35 (4H, d, J = 8.1 Hz, Ph), 8.30-
8.21 (6H, m,
Ph), 7.84-7.72 (9H, m, Ph), -2.71 (2H, s, NH). ES! MS found m/z= 1227.5
([M+Hr),
calcd for C881158N8 , rig& = 1227.5
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(c) Sulfonation of porphyrin (TPP)2 to produce (TPPS3)2, modified from the
literature
method23.
30 mg of (TPP)2 was allowed to react in 2 ml of conc. Sulfuric acid at 80 C
for 9 h. The
solution turned from red to green upon acidifying. After the reaction, the
porphyrin
solution was poured into a beaker of ice, diluted and neutralized with 1 M
NaOH until
the solution turned deep red. The solution was concentrated and the porphyrin
solution
was rinsed off from Na2SO4 salt with cold water. The porphyrin solution was
dialyzed
using a 3500 MWCO membrane to remove the excess salt. 40 mg of product was
obtained (96 %).111 NMR (500 MHz, DMSO-d5): 59.06 (4H, d, J = 4.6 Hz, por-I1),
8.98
411, d, J = 4.6 Hz, por-11), 8.87 (8H, s, 8.49 (811, m, Ph), 8.25-8.15
(12H, m, Ph),
8.12-8.00(12H, m, Ph), -2.86 (4H, s, NH). ESI MS found mlz= 283.4 ((Mr), calcd
for
C88H48N8018S66" , rn/z = 283.4.
(d) Mn insertion into porphyrin (TPPS3)2 to produce (MnIPPS3)2.
10.7 mg (5 eqv) of Mn(OAc)2 and 10 mg (1 eqv) of (TPPS3)2 was used for Mn
insertion.
The reaction occurred for overnight at 115 C with stirring in 3 ml of DMF.
DMF was
removed by distillation. The crude product was dried and dissolved in pure
water.
Dialysis was used to separate bulk excess salt. RP column was subsequently
used to
remove excess salt. Ion-exchange column was used to replace possible Mn2+
counter
ions into Na s ions. 11 mg (97%) of dark green solid product was obtained. ESI
MS
found m/z= 451.5048 ((MP"), calcd for C88H481\18018S6Mn24" , m/z = 451.5047.
UV-vis
(HEPES buffer, pH =7.0) Aabs = 382, 402, 421, 469, 569, 602 nm.
(e) The synthesis of 5,10,15,20-tetrakis(ethoxycarbonyl)porphyrin, 11.
The procedure was performed with a slight modification of the literature
method.24 Ethyl
*oxalate (50 % in toluene, 1.88 ml, 9.4 mmol) in dichloromethane and pyrrole
(0.65 ml,
9.4 mmol) were stirred at room temperature, in the dark and under an argon
atmo-
sphere. After 10 min BF3.0Et2 (42 ml, 3.10mmol) was added drop wise. The
reaction
was stirred at room temperature for 1.25 h followed by the addition of MX)
(1.5999 g,
7.05 mmol). After a stirring period of 2.25 h NEt3 (0.43 ml, 3.06 mmol) was
added via
syringe and the reaction mixture was concentrated on a rotary evaporator. The
crude
solution was suction filtered over sealite using DCM as an elution solvent.
The solution
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CA 02805543 2013-02-12
was concentrated on a rotary evaporator. Purification by column chromatography
(DCM)
on silica gel gave 169.2 mg (12 %) of compound 7 as a black-purple solid. 1H
NMR (500
MHz, CDCI3) 9.52 (811, s, pot-0), 5.11 (8H, q, J = 7.2 Hz), 1.81(12H, t, J =
7.2 Hz), -3.33
(2H, s, NH). UV-vis (DCM) Amax = 409 nm.
(f) The synthesis of [5,10,15,20-
tetrakis(ethoxycarbonyl)porphyrinatolmanganese(III)
chloride, Mn-11,
The current step was performed according to the literature method.24 Compound
11
(17.8 mg, 29.7 pmol) was dissolved in 2 ml of DMF. MnC12.4H20 (17.7mg, 89.2
pmol)
was added and the reaction was refluxed open to air for 5 h. The reaction was
stirred at
room temperature open to air for a further 11.5 h. Distillation of DMF
resulted in a black-
purple solid. Purification by stepped gradient column chromatography (eluting
with DCM
to 7 % Me0H in DCM) on silica gel gave 16.5 mg (85 /0) of compound Mn-11 as a
black-purple solid. ESI MS found miz = 651.1 ([10) , calcd for C32H28MriN408+,
m/z =
651.1. UV-vis (Me0H)
¨alas 328, 366, 387, 413, 456, 552 nm.
(g) Synthesis of [5,10,15,20-tetrakis(carboxy)porphyrinato}manganese(III)
chloride,
MnTCP.
Ethanol (10 ml) and 2 M Na011(a,4) (10 ml) were added to a solution of 7(14.3
mg, 21.9
pmol ) in 6 ml of THF. The reaction was refluxed for 12 h followed by
neutralization with
3 M H2S040co. Purification by sephadex LH-20 chromatography with ultrapure
water
gave the desired product in 85 % yield. ESI MS found m/z = 539.0030 pin, calcd
for
C24H12MnN408+, m/z = 539.0034. UV-vis (Hepes buffer, pH = 7.0) )tabs = 325,
377, 397,
421, 465, 561, 592 nm.
-66 -
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