Note: Descriptions are shown in the official language in which they were submitted.
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. ' ACETYLDICARNITINE
1 The,present invention refers to an intermolecular
ester of dicarnitine having a therapeutic action.
More particularly, the present invention refer$ to
Acètyldicarnitine dichloride having the following general
formula:
, CH3 '
CH3~-CH2-CH-CH2-cOOH ICH3 2 C1
, ' CH3 1_lCI_CH2_CIH CH2 CH 3
O O-C-CH3 3
_ ' _
Further object of the present invention is a process
for the preparation of Acetyldicarnitine dichloride.
According to the present invention, the preparation
Of Acetyldicarnitine dichloride of formula I is essen-
tially based on two alternative reactions. The former
consists in transforming the acetylcarnitine chloride in
the corresponding acyl chloride by treatment with thionyl
chloride and further esterification with carnitine
chloride in a single step.
According to the alternative reaction the starting
compound is dicarnitine dichloride intermolecular ester
of carnitine, obtained in a single step by treatment of
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; 1 carnitine chloride with thionyl chloride and further
acetylation of the secondary free alcoholic group, in
known manner, by reaction with acetic anhydride or acetyl
chloride as an acylating agent.
The use of thionnyl chloride as acid catalyst and
dehydrating agent is known in the literature.
The transformation of the carboxyl group into the
corresponding acyl halide and the consequent easier
esterification with the alcoholic substratum present in
the reaction mixture, represents a very peculiar and
important synthesis capable to promote both the
condensation of the two moles of carnitine and the
acetylation of the obtained dicarnitine by further
addition of acetic anhydride or acetyl chloride.
The reaction may be carried out in a single step
starting from carnitine chloride or from acetylcarnitine,
without isolation of the intermediate compounds so
obtained.
An important object of the present invention consists
2Q in having found the peculiar conditions of the process of
the invention. Consequently, an optimal control of these
conditions is very important and critical. Furthermore,
it has been found that an extended heating or high
temperature cause the dehydration to ~-trimethylamino
crotonic acid.
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1 Moreover, the compound obtained by the process of the
invention is rather labile and it is easily hydrolized in
acidic medium, so that its separation from the reaction
mixture is very critical. It has been found that the
isolation is preferably carried out immedia~ely and very
accurately. On th`e other hand, also the processes known
in the literature require special accuracy.
Preferably, the process for preparing Acetyldicarni-
tine dichloride of the invention is carried out starting
from a mixture of acetylcarnitine chloride and freshly
distilled thionyl chloride,in a molecular ratio of 1:1.5.
The mixture is allowed to stand under stirring for a
period of 0.5-2 hours at room temperature. The acyl
chloride of acetyl carnitine so obtained, dissolved in
methylene chloride, is added with an equivalent quantity
of carnitine chloride and allowed to stand for a period
of 18-36 hours at 380-420C. The raw product so obtained
is separated and purified in known manner.
Acute toxicity: Acetyldicarnitine dichloride of the
invention is pratically a non toxic compound.
It has been found that LD50 by oral administration is
higher than 20g/kg (body weight) in mice and higher than
15g/kg in rats. By intravenous administration, LD50 is
higher than 0.75gikg in mice, higher than 1g/kg in rats
and higher than 2.5g/kg in dogs.
, - 4 - 12 ~ 9
l Pharmacody amics
By oral administration of Acetyldicarnitine
dichloride at the dose of 100 mg/kg (body weight) in mice
and senile rats (about 20 months aged) it was noticed an
increase of curiosity and reactivity and an improvement
of the motory coordination.
On the ground of the pharmacological trials carried
out to establish the pharmacokinetic characteristics of
the product of the invention and to study its meta-
l~ bolism, it has been found that Acetyldicarnitinedichloride spilts off into L-acetyl-carnitine and
L-carnitine in the organism.
Consequently, the compound of the present invention,
. in addition to the pharmacological properties of L-carni-
tine which, as known to the experts, activates the
proteic metabolism and stimulates the digestive secre-
tions with an anabolic and antianorexic action, shows
some original and unexpected properties.
More particularly, the compound of the invention is
expecially active in the treatment of the senile and
pre-senile cerebral involution syndromes of primary and
secondary etiology tvasculoPaties) and in cases of alte-
ration of memory and attention in elderly men.
Furthermore, the compound of the present invention is
active in the therapy of cardiopahies~ such as, for
~256119
1 example, acute and chronic myocardic ischemia, angina
pectoris, latent and clear cardiac insufficiency and
arhytmias~ L-acetildicarnitine is also endowed of a
cardioprotective effect against damages on the heart
induced by the use of anthracyclines antitumor drugs.
Furthermore, due to its most favourable pharmaco~inetic,
the product has a higher bioavailability, resulting in a
better effect in comparison with other available drugs.
Further scope of the present invention are the
pharmaceutical compositions containing acetyldicarnitine
dichloride.
The pharmaceutical compositions, administrable
by oral or parenteral route, are active therapeutic agents
for the treatment of the senile and pre-senile cerebral
involution syndromes of primary Or secondary etiology, for
the treatment of alteration of the memory and attention
in elderly patients as well as of vascular diseases. The
pharmaceutical compositions comprise a therapeutically
effective amount of acetyldicarnitine dichloride and a
pharmaceutically acceptable carrier and/or diluent for
oral or intramuscular~ administration.
The suggested amount of acetyldicarnitine dichlo-
ride for human patients is between 0.5 and 2.0 g pro die.
The following non-limitative examples illustrate
the invention.
125~
1 'EXAMPLE 1
Prep'a'ration o'f L'-'a'cetylcarnitine chloride
According to the method described in the litera-
ture (Zegler et al. J. Org. Chem., 1967, p.3989) 50 ml of
acetic acid were added with 8 g of acetyl chloride and
maintained under stirriny for 3 hours, at 80C. After
addition of 9.9 g of carnitine, the reaction mixture was
allowed to stand under stirring for 1 hour, at 80C. A
very thick liquid obtained by distillation, in vacuo, was
then added with 40 ml of boiling isopropanol.
The reaction mixture was filtered to remove the
non-reacted carnitine and the product of the title
precipitated slowly by addition of 50 ml of acetone. A
white crystalline solid was obtained.
(yield of 98~), m.p. 180-182C.
Ace*y'ldica'rnitine' dich'lo'r'ide
0.15 moles of freshly distilled thionyl chloride
were added to 0.1 mole of L-acetylcarnitine chloride.
The mixture was allowed to stand under stirring
for about 1 hour, at room temperature.
A~ter having removed the excess thionyl chloride
by distillation under reduced pressure, the corresponding
acyl chloride was obtained as a white spongy solid, which
can be easily hydrolyzed in the air.
The acyl chloride so obtained was dissolved in
30 ml of anhydrous methylene chloride and then added with
0.105 moli of L-carnitine chloride. The resulting mixture
~2S6119
1 was allowed to stand under stirring for 24 hours at 40 C.
The reaction was followed by thin layer chromatography up
to L-acetylc~rnitine acyl chloride completely disappeared.
After removing the solvent by evaporation unaer
reduced pressure, the raw product was washed many times
with small amounts of methylene chloride.
The white, spongy, very hygroscopic solid
compound so obtained was dissolved in the minimum quantity
of isopropanol (about 150 ml) and then filtered to remove
the unreacted carnitine and acetyl carnitine.
From the filtrate the product precipitated by
addition of acetone (300 ml) in the form of white, very
hygroscopic solid which was washed more times wi~h small
amounts of acetonitrile (about 20 ml) to remove all traces
of esters.
The title compound was obtained (yield 90%):
IR (DMSO) ~max 1740, 1715 cm
IR (KBr) ~max 3550, 2995, 2950, 2900, 1730 cm
MS (field desorption) 347, 305, 287, 204, 162 m/e
'H-NMR (200 MHz, DMSO-d6, 22 C)
2.02 (s, 3H, COCH3)
2.7-2.8 (m, 4H, CH-CH2-COO-CH-CH2-COOH)
OCOCH~
3.20 (s, 18H, 2 x N (CH3)3
3.8-4.1 (m, 4H, N -CH2-CH-CH2-COOCH-CH2-N
I
OCOCH3
OCOCH3
5.43 (m, 2H, -CH-CH2-COO-CH-CH2COOE~)
125S~l~
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l EXAMPLE 2
.
Acetytdicarnitine dichloride
19.7 9 (0.1 moles) of carnitine~chloride and 35.7 9
(0.3 moles) of thionyl chloride were allowed to stand in
a flask, under stirring, for about 8 hours, at 30C.
The excess thionyl chloride was removed under reduced
pressure. After addition of 10 ml of water the reaction
mixture was evaporated to dryness.
The raw product was taken up with hot isopropyl
alcohol, filtered and after removing the unreacted
carnitine and ~-trimethylamino-crotonic acid, if
present, the fiItrate was allowed to crystalli~e.
The precipitate so obtained was then dissolved in
10.2 9 (0.1 moles) of acetic anhydride and the solution
was allowed to stand under stirring for about 12 hours,
at 40C~
The excess acetic anhydride and acetic acid was
removed by distillation under reduced pressure on a water
bath (40C).
2~ The viscous residue was dissolved in hot isopropyl
alcohol and from the reaction mixture the title product
was separated in known manner in the form of hygroscopic,
white so!id.
EXAMPLE 3
.
25 Preparation of an injectable pharmaceutical composition
_ 9 _ ~2 ~61 1~
l The preparation is carried out according to the
conventional processes well known per se to those skilled
in the art.
The preferred composition of an injectable form is:
acetyldicarnitine dichloride 500 mg
glycine 750-mg
distilled water 5 ml
EXAMPLE 4
Preparation of an oral pharmaceutical composition
1~ The preparation is carried out according to the
conventional processes well known per se to those skilled
in the art.
The preferred composition of an orally administrable
form tbottle of about 15 ml) is:
acetyldicarnitine dichloridel 9
70% sorbitol aqueous solution5 9
methyl p-hydroxybenzoate0,010 9
apricot essence 0,015 9
orange essence 0,025 9
distilled waterup to 10 ml vol.
