Note: Descriptions are shown in the official language in which they were submitted.
NAPHl~IALENEPROPIONIC ACID DERIVAl~V~S ~ ~ -
AS ANT[-lNELAM~q~TORY/ANT~ALLE12GIC AG13NTS
This invention relates to novel naphthalenepropionic acid ~ ;
derivatives possessing lipoxygenase inhibitory and leukotriene antagonist
5activity, which are useful as anti-inflamrnatory and antiallergic agents. ~ ;
It is known that arachidonic acid (AA) is metabolized in mammals
by two distinct pathways. The metabolism of arachidonic acid by cyclooxy-
genase enzymes results in the production of prostaglandins and thromboxanes.
The physiological activity of the prostaglandins has already been amply
10elucidated in recent years. The other pathway of AA metabolism involves
lipoxygenase enzymes and results in the production of a number of oxidative
products called leukotrienes. The latter are designated by the LT
nomenclature system, and the most significant products of the lipoxygenase
metabolic pathway are the leukotrienes B4, C4, D4 and E4. The substance
denominated slow-reacting substance of anaphylaxis (SRS-A) has been shown
to consist of a mixture of sulfidopeptide leukotrienes, C4, D4 and E4 [see Bach - -
et al., J. Immun., 215, 115-118 (1980); Biochem. Biophys. Res. Commun. 93,
1121-1126 (1980) ] . -~
The significance of these leukotrienes is that a great deal of
20evidence has been accumulated showing that leukotrienes participate in
inflammatory reactions, exhibit chemotactic activities, stimulate lysosomal
enzyme release and act as important factors in the immediate hypersensitivity
reaction. It has been shown that LTC4 and LTD4 are potent broncho~
constrictors of the human bronchi [see Dahlen et al., Nature 288, 484-486
25(1980) and Piper, Int. Arch. Appl. Immunol., 76, suppl. 1, 43 (1985)] which
stimulate the release of mucus from airways in vitro [Marom et al., Am. Rev.
Resp. Dis., 126, 449 (1982)], are potent vasodilators in skin [see Bisgaard et al,
Prostaglandins, 23, 797 (1982)], and produce a wheal and flare ~esponse [Camp
et al., Br. J. Pharmacol" 80, 497 (1983)]. The nonpeptide leukotriene, LTB4,
30is a powerful chemotactic factor for leukocytes [see A.W. Ford-Hutchinson, J.
. Soc. Med.~ 74, 831-833 (1981)], which stimulates cell accumulation and ;
affects vascular smooth aluscle [see Bray, Br. Med. Bull., 39, 249 (1983)]. The
activity of leulcotrienes as mediators of inflammation and hypersensitivity is
extensively reviewed in Bailey and Casey, Ann. Reports Med. Chem., 17, 203-
35217 (1982) and in Bray, Agents and Actions, ~, 87 (1986).
~ ' ~
-" L 3 3 ~
Acco~dingly, the biological activity of the leukotrienes and SRS's,
and of lipoxygenase as the enzyme leading to the metabolism of AA to
leukotrienes, indicates that a rational approach to drug therapy to prevent,
remove or ameliorate the symptoms of allergies, anaphyIaxis, asthma and
5 inflammation must focus on either blocking the release of mediators of these
conditions or antagonizing their effects. Thus compounds, which inhibit the
biological effects of the leukotrienes and SRS's and/or which control the
biosynthesis of these substances, as by inhibiting lipoxygenase, are considered
to be of value in treating such conditions as allergic bronchial asthma, allergic
10 rhinitis, as well as in other immediate hypersensitivity reactions.
It has now been found that certain noveI naphthalenepropionic acid
derivatives inhibit lipoxygenase and antagonize products of the lipoxygenase
pathway, and so are useful as antiinflammatory and anti-allergic agents. The
present invention provides novel compounds having the following formula~
CH3
;~ CHCOOH
~CH20 ~1
wherein
X is N or CR;
Z is -Cl - I -, -C=N-, -N= IC-, -N-, S or O;
R R R R R
R is hydrogen or lower alkyl;
Rl is hydrogen or lower alkyl;
R2 is hydrogen or lower aL'cyl; or
Rl and R2 taken together form a benzene ring;
and the pharmaceutically acceptable salts thereof. ~ ;
The term "lower alkyl" refers to moieties having 1 to 6 carbon
25 atoms in the carbon chain.
1 3 3 ~
- 3 -
The compounds of the invention can be readily prepar~d according
to the following reaction sequence~
f H3
CHCOOH :
R2~C--Z ~ NaOCH
', "-~
2 ~C Dl~ I OC--
CH3
HCOOH
NnOII > ~ ~CN20
R.
The starting materials used in the above reaction sequence are
available commercially or can be prepared by known methods conventional in
~` ~ the art. Thus, for example, the benzo-fus:e: heterocyclic compounds such as
l-methyl-2-chloromethylbenzimidazole, 2-chloromethylbenzthiazole and 2-
10 chloromethylbenzoxazole can be prepared by the following reaction scheme:
~ Cl 112C--OCR3 ~ ~C112CI
wherein X is O, S or NCH3. The reaction is preferably carried out at a ;
controlled low temperature in an organic solvent, such as methylene chloride. .:
,; ;~
., ~ .-,.
: -:.-: : :.
~'.,~
~ ~ 3 3 ~
- 4-
Compounds of the invention which contain a basic nitrogen are
capable of forming pharmaceutically acceptable salts, including the salts of
pharmaceutically acceptable organic and inorganic acids such as hydrochloric,
hydrobromic, sulfuric, nitric, phosphoric, methanesulfonic, benzenesulfonic,
5 acetic, citric, fumaric, maleic, succinie and the like.
The compounds of the invention, by virtue of their ability to inhibit
the activity of lipoxygenase enzyme and to antagonize mediators arising from
this enzymatic pathway, are useful in the treatment of inflammatory
conditions. Accordingly, the compounds are indicated in the treatment of such
10 diseases as rheumatoid arthritis, osteoarthritis, tendinitis, bursitis and similar
conditions involving inflammation. Moreover, by virtue of their ability to
inhibit the activity of lipoxygenase enzyme and by their ability to antagonize
the effect of LTC4, LTD4 and LTE4 which are the constituents of SRS-A, they
are useful for the inhibition of symptoms induced by these leukotrienes.
15 Accordingly, the compounds are indicated in the prevention and treatment of
those disease states in which LTC4, LTD4 and LTE4 are causative factors, for
example allergic rhinitis, allergic bronchial asthma and other leukotriene
mediated naso-bronchial obstructive air-passageway conditions, as well as in
other immediate hypersensitivity reactions, such as allergic conjunctivitis
20 The compounds are especially valuable in the prevention and treatment of
allergic bronchial asthma.
When the compounds of the invention are employed in the
treatment of allergic airway disorders and/or as antiinflammatory agents, they
can be formulated into oral dosage forms such as tablets, capsules and the
25 like. The compounds can be administered alone or by combining them with
conventional carriers, such as magnesium carbonate, magnesium stearate,
talc, sugar, lactose, pectin, dextrin, starch, gelatin, tragacanth, methyl~
cellulose, sodium carboxymethylcellulose, low melting wax, cocoa butter and
the like. Diluents, flavoring agents, solubilizers, lubricants, suspending agents,
30 binders, tablet-disintegrating agents and the like may be employed. The
compounds may be encapsulated with or without other carriers. In all cases,
the proportion of active ingredients in said compositions both solid and liquid
will be at least to impart the desired activity thereto on oral administration.
The compounds may also be injected parenterally, in which case they are used
35 in the form of a sterile solution containing other solutes, for example, enough
saline or glucose to make the solution isotonic. For administration by
:. .,' ,, .,', ',
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inhalation or insufflation, the compounds may be formulated into an aqueous
or partially aqueous solution, which can then be utilized in the form of an
aerosol.
The dosage requirements vary with the particular compositions
5 employed, the route of administration, the severity of the symptoms presented
and the particular subject being treated Treatment will generally be initiated
with small dosQges less than the optimum dose of the compound. Thereafter
the dosage is increased until the optimum effect under the circumstances is
reached. In general, the compounds of the invention are most desirably
10 administered at a concentration that will generally afford effective results
without causing any harmful or deleterious side effects, and can be
administered either as a single unit dose, or if desired, the dosage may be
divided into convenient subunits administered at suitable times throughout the
day.
The lipoxygenase inhibitory and leukotriene antagonist effects as
well as the antiinflammatory effects of the compounds of the invention may
be demonstrated by standard pharmacological procedures, which are described
more fully in the examples given hereinafter.
These procedures illustrate the ability of the compounds of the
20 invention to inhibit the polymorphonuclear leukocyte synthesis of the lipoxy~genase product 5-HETE; the in vivo ability of the compounds to inhibit
bronchospasm induced by exogenously administered mediators of bronchocon~
striction; and measure the in vivo activity of the compounds as anti-
inflammatory agents in the rat carrageenan paw edema assay.
The following examples show the preparation and pharmacological
testing of compounds within the invention.
~.: ..
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Example 1 ~ -
.
ethyl~2~oinolinylmethoy~2-naphthaleneacetie acid - n - ~
.
To a solution of 6-hydroxy-o~-methyl-2-naphthaleneacetic acid
(10.8 g, 50 mmol) in methanol (100 ml) is added sodium methoxide (100 mmol).
5 After 10 minutes the solvent is removed and replaced with dimethylformamide
(250 ml). 2-(Chloromethyl)quinoline (17.8 g, 100 mmol) is then added and the
reaction mixture is stirred for 8 days at room temperature. The reaction
mixture is partitioned between water and methylene chloride, the organic
layer is washed with water and evaporated to yield 27 g of an oil.
10 Recrystallization of this oil twice from acetonitrile gives 10.6 g of white ~;
crystals of intermediate ether ester (4296 yield, m.p. 106-108C).
The ether ester from above is hydrolyzed as follows: a solution of
the ether ester (14.4 g, 28.9 mmol) in a mixture of 110 ml of lN NaOH and
110 ml tetrahydrofuran is refluxed for 1 hour. The organic solvent is then
~; 15 removed and 2-(hydroxymethyl)quinoline is filtered off. The aqueous solution
~; is acidified to pH 6 and the precipitate is filtered and recrystallized from -~
ethanol to afford 2.2 g of white crystals (21% yield, m.p. 186-187C).
Analysis for: C23HlgNO
Calculated: C, 77.30; H, 5.36; N, 3.92. ;~
20 Found: C, 77.69; H, 5.36; N, 3.93.
Example 2
a-Methyl~6~phenylmetho2~y~2-naphthaleneaceti~ acid -
.,: .: ~- . .
To a solution of 6-hydroxy-~ -methyl-2-naphthaleneacetic acid
(6.48 g, 30 mmol) in methanol (100 ml) is added sodium methoxide (60 mm).
25 After 10 minutes the solvent is removed and replaced with dimethylformamide
(100 ml). Benzyl chloride (7.6 g, 60 mm) is then added and the reaction
mixture is stirred overnight at room temperature. The reaction is then heated
; at 150 C for 1 hour. The solvent is then removed and the residue is
partitioned between water and methylene chloride. The organic layer is
30 washed with water, dried over magnesium sulfate and evaporated to 11.5 g of
crude product. This crude product is extracted with 100 ml hot hexane which
affords 3.5 g of white crystals. A final recrystallization from methanol
affords 2.5 g of white crystals of the intermediate ethyl ester (21% yield, m.p.76-78C).
` `,',~,..
'~'` ' ;'';"'~''
~l 3 3 ~
- 7 -
The ether ester (~.2 g, 5.56 mmol) ;s hydrolyzed using the method
of Example 1. Recrystallization from ethanol affords 1.1 g of white crystals
(65% yield, m.p. 149-151C).
AnalysiS for: C20H183
Calculated: C, 78.40; H, 5.92.
Found:G, 78.31; H, 6.02.
Example 3
~-Nethyl~-l(l-methyl-lH~enz:imida~:ol-2-yl)
methoy ]-2-naphthaleneacetic acid -
10 The procedure of Example 2 is followed on a 10 mmol scale,
substituting 2-chlormethyl-N-methyl-benzimidazole for benzyl chloride. ~-
Normal workup affords 2.5 g of white crystals of ether ester (50% yield, m.p.
228-230C). This material is analytically pure and needs no recrystallization.
The ether ester (2.5 g, 4.9 mmol) is hydrolyzed according to the
15 method of Example 1. Recrystallization from ethanol affords 0.75 g of white -~
crystals (43% yield, m.p. 216-219C).
Analysis for: C22H20N2o3 3/4 H2O
Calculated: C, 70.66; H, 5.79; N, 7.49.
Found: C, 70.89; H, 5.72; N, 7.28.
Example 4
-Methylff~2-pyridinylmethoy~2-n~phthaleneaceti~ acid
To a solution of 6-hydroxy-u-methyl-2-naphthaleneacetic acid
(10.8 g, 50 mmol) in methanol (100 ml) is added sodium methoxide (100 mmol).
After 10 minutes the solvent is removed and replaced with hexamethyl- -
25 phosphoric triamide (250 ml). 2-Chloromethyl-pyridine (100 mmol) is then ~ ~ :
added and the reaction is stirred for 5 days. The reaction is worked up by
partitioning between water and methylene chloride, and the organic extract is
evaporated to a crude oil which is chromatographed on silica gel (eluant: ~ -
methylene chloride - ethyl acetate) to afford 6.0 g of ether ester as an oil.
The ether ester is hydrolyzed using the method of Example 1.
Recrystallization from ethanol affords 5.5 g of white crystals ~36% yield, m.p.
185-187 C). ~ -
.~ ' -~::'' '~
.~.,,:
- 3 3 3 a ~
-- 8
Analysis for: ClgH17NO3
Calculated: C, 74.24; H, 5.57; N, 4.56.
Pound: C, 74.49; H, 5.63; N, 4.49.
13xample 5
The compounds 5- and 12-hydroxyeicosatetraenoic acid (5-HETE
and 12-HETE) and 5,12-dihydroxyeicosatetraenoic acid (5,12-diHETE;) are early
arachidonic acid oxidation products in the lipoxygenase cascade, which have
been shown to mediate several aspects c>f inflammatory and allergic response.
The assay of this Example measures the ability of the compounds of the
invention to inhibit the synthesis of 5-HETE by rat glycogen elicited poly-
morphonuclear leukocytes.
The assay is carried out as follows: -~
Peritoneal PMN are obtained from female Wistar rats (150-250 g)
that received an i.p. injection of 6% glycogen (10 ml). After 24 hours, rats
are killed by CO2 asphyxiation and peritoneal cells are harvested by peritoneal
lavage using Ca++and Mg++ free Hanks' balanced salt solution (HBSS). The
peritoneal exudate is centrifuged at 400 g for 10 minutes. After
centrifugation, the lavaged fluid is removed and the cell pellet is resuspended
in HBSS containing Ca++ and Mg++ and 10 mM L-cysteine at a concentration
~ `
of 2 x 107 cells/ml. To 1 ml portions of cell suspension, test drugs or vehicle
are added and incubated at 37C fsr 10 minutes. Following this preincubation,
the calcium ionophore (10 ,uM), A23187, is added together with 0.5 llCi ~14C]
~ -
arachidonic acid and further incubated for 10 minutes. The reaction is stopped
by the addition of ice cold water (3 ml) and acidifying to pH 3.5. Lipoxygenase
-~
products are then extracted twice into diethyl ether. The pooled ether
~
extracts are evaporated to dryness under nitrogen and the residue is
~ - ;
redissolved in a small volume of methanol and spotted on aluminum backed
pre-coated thin layer chromatographic plates. The samples are then
cochromatographed with authentic reference 5-HETE in the solvent system
hexane: ether: acetic acid (50:50:3). After chromatography, the areas
associated with 5-HETE standard are identified by autoradiography, cut out
and quantitated by liquid scintillation.
-
The compounds of the invention, when tested in this assay at the ;
~` level of lO uM, gave the following results in inhibiting the synthesis of the
arachidonic acid lipoxygenase oxidation product 5-HETE.
,'~', ~
~"'''''" "''
. :
1 3 ~
g
.
TQble 1
Compound of % Inhibition of 5-LO
Example No. (as 5-HETE)
100 :: .
2 84
3 24
4 82
' '~
These results show that the compounds of the invention exhibit
very significant activity in inhibiting the enzyme, lipoxygenase.
. . ~:
El~ample fi
The procedure of Example 5 is also employed for the determination
of the ability of the compounds of the invention to inhibit the synthesis of thearachidonic acid cyclooxygenase oxidation product TxB2.
In this assay, the procedure of Example 5 is carried out as
15 described. EIowever, in order to determine cyclooxygenase activity, the
samples are cochromatographed with authentic reference TxB2 in the solvent
system ethyl acetate:formic acid (80:1) and the upper phase of ethyl
acetate: isooctane: acetic acid: water (110:50:20:100). After chromato~
graphy, the areas associated with the TxB2 standard are identified by
20 autoradiography, cut out and quantitated by liquid scintillation techniques.
The results are calculated as in Example 5.
When tested in this assay the compounds of the invention, at a
level of lO uM gave the following results in inhibiting the synthesis of the
arachidonic acid cyclooxygenase oxidation product TxB2.
Table 2
Compound of % Inhibition of CO
(as TxB2)
28
2 6
3 1
4 12
: . :: .
~ ~:
~ 3 ~
- 10 -
These results show that the compounds of the invention are
virtually devoid of cyclooxygenase inhibitory activity, having activity
substantially only on the lipoxygenase pathway of arachidonic acid oxidation.
Exam~le 7
The assay of this Example measures the in vivo ability of the
compounds of the invention to inhibit the bronchospasm induced in guinea pigs
by the exogenously administered leukotrienes C4 and/or D4.
This assay is carried out as follows:
Male Hartley strain guinea pigs (350-600g) are anesthetized with
pentobarbital sodium (50 mg/kg, i.p.). The jugular vein is cannulated for~
injection of drugs and the carotid artery for monitoring blood pressure. The
trachea is cannulated for artificial ventilation by a miniature Starling pump
and for indirect measurement of respiratory volume changes. The animals are
then pretreated with succinylcholine (2 mg/kg i.v.) and indomethacin (10
mglkg i.v. in trizma 8.3 buffer, 9 minutes prior to~ leukotriene challenge).
Submaximal bronchoconstrictor responses are established in control animals by
varying the dose-levels of leuko~riene. Intravenous dose-levels for LTC4 range
from 0.4 to 0.6 ~Ig/kg and for I.TD4 the range is from 0.3 to 0.5 llg/kg. Th~e
aerosol bronchoprovocation dose for LTC4 is generated from 1.6 tlM solution
and for LTD4 from a 2.0 ~IM solution.
Test drugs (dissolved in a solvent such as propylene glycol,
polyethylene glycol 400 or saline) are administered either intraduodenally, by
aerosol or intragastrically at 2 or l0 minutes before induction of bronchospasm
by administration of either LTC4 or LTD4 at the predetermined dose-levels.
Aerosols of soluble drugs or leukotrienes are produced in-line for l0 seconds
only by actuation of an ultrasonic nebulizer (Monaghan). Aerosolized drug
dosage is expressed in terms of solution concentration and by a fixed aerosol
~` exposure time (approximately 10 seconds). Control animals receive solvent (2
ml/kg i.d. or appropriate aerosol) in place of drug.
Respiratory volume changes are determined by a calibrated piston
whose travel is recorded, ~via a linear transducer, on a Beckman- Dynograph
` ~ ` re~order. Maximal bronchoconstrictor volume is determined by clamping off
the trachea at the end of the experiment. Overflow volumes ~t 1, 3 and 5
minutes are obtained from the recorded charts.
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Area under the volume overflow curve (AUC) is estimated, using
the overflow values at 1, 3 and 5 minutes, and expressed as a percentage of
the maximal overflow AUC (equation l):
3 (l min) + 4 (3 min) -~ 2 (5 min)
% max AUC = - -- X lO0 (l ~ :~
l0 (max)
5 Drug effects are reported as percent inhibition of % max AUC values obtained
from appropriate control animals (equation 2):
% max AUC control- % max AUC treated
% inhibition = X 100 (2
~: % max AUC control
Student's t-test for unpaired data is used to determine statistical
significance (p < 0.05). ICso values can also be determined by inverse
10prediction from linear regression lines through points between 10 and 90% ~ ~ :
inhibition. .
The results for compounds of the invention are as follows: ~-
Table 3
~: Compound administered at 10 minutes before induction of bronchospasm .
15using LTD4
:~ Compound of Dose*
Example Number mg/kg% Inhibition ~ :~
l 25 ~5 :
2 25 -76
20 3 25 80
4 25 52 : ~
* = intraduodenally administered - : ::: ~:
The results show that compounds of the invention have significant :
in vivo activity against LTD4 induced bronchoconstriction. ~
' .'.~ :,,
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- 12 -
E~cample ~
The compounds of the invention are further tested in the rat
carrageenan paw edema assay to determine their ability to inhibit the acute
inflammatory response.
This assay is carried out as follows: ;~
140-180 gm male Sprague-Dawley rats, in groups of 6 animals are -
injected subcutaneously in the right paw with 0.1 ml of 1% carrageenan at -~
zero time. Mercury plethysmographic readings (ml) of the paw are made at
zero time and 3 hours later. Test compounds are suspended or dissolved in
0.5% methylcellulose and given perorally 1 hour prior to carrageenan
administration.
The increase in paw volume (edema in ml.) produced by the
carrageenan is measured. Paw edema is calculated (3 hour volume minus zero -
time volume), and percent inhibition of edema is determined. Unpaired ~ ~ -
Student's t-test is used to determine statistical significance. -
The activity of standard drugs in this assay is as follows:
Dru~ Oral EDso (95% C.L.~ m~/kF ~- -
Indomethacin 3-7 t0.6, 23.8)
Aspirin * 145.4 (33.1, 645.6)
Phenylbutazone 26.2 (2.3, 291.0)
When tested in this assay, the compounds of the invention gave the
following results:
Table 4
Compound of% Inhibition at
25 ExamDle No.50 mg/kg (peroral)
` ~ 1 42
2 24
3 32
4 30
~: :
The results show that the compounds tested have activity in the rat
carrageenan paw edema assay, evidencing an effect on the acute inflammatory ~ ~ `
response.
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