JPH0147463B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention relates to mercapto fatty acid derivatives useful for uses such as agents for treating hypertension, and methods for producing the same. More specifically, the present invention is based on the following formula () However, in the formula, R ₁ represents a hydrogen atom or a lower alkyl group, R ₂ represents a lower alkyl group, A represents S or SO ₂ , m represents 0 or 1, n represents 1 or 2, * indicates an asymmetric carbon atom, and ** indicates an asymmetric carbon atom when R ₁ is a lower alkyl group. However, in the above formula, when A is S and n = 2, R ₂ represents a group other than CH ₃ , and relates to mercapto fatty acid derivatives and salts thereof represented by: Furthermore, the present invention also relates to a method for preparing the above-mentioned compounds. The above-mentioned formula () compound and its salts are compounds that have not been described in any known literature. The present inventors have conducted research on mercapto fatty acid derivatives. As a result, the above formula ()
We have succeeded in synthesizing derivatives that have not been described in any prior art literature and can be expressed by: Therefore, an object of the present invention is to provide a compound of formula () and a method for producing the same. The above objects and many other objects and advantages of the present invention will become more apparent from the following description. In the above formula (), examples of the lower alkyl groups for R ₁ and R ₂ include C ₁ -C ₄ alkyl groups, particularly preferably C ₁ -C ₂ alkyl groups. The compound of formula () of the present invention is, for example, the following:
It can be produced by method (A) or method (B). (A) Method: − The following formula () However, in the formula, R ₂ represents a lower alkyl group, A represents S or SO ₂ , and n represents 1 or 2. However, in the above formula, when A is S and n=2, is an aminocarboxylic acid derivative represented by R ₂ represents a group other than CH ₃ and the following formula () However, in the formula, R ₁ represents a hydrogen atom or a lower alkyl group, and m represents 0 or 1. A method of reacting a mercapto fatty acid or its reactive derivative represented by the following formula. (B) Method: − The following formula () However, in the formula, R ₁ represents a hydrogen atom or a lower alkyl group, R ₂ represents a lower alkyl group, A represents S or SO ₂ , X represents a halogen atom, m represents 0 or 1, n represents 1 or 2, * represents an asymmetric carbon atom, and ** represents an asymmetric carbon atom when R ₁ is a lower alkyl group. However, in the above formula, A is S and n = 2, R ₂ represents a group other than CH ₃ , and a compound represented by the following formula () R ₃ SH () where R ₃ is an alkanoyl group, an aroyl group, an N-alkylcarbamoyl group, The following formula ( ) However, in the formula, R ₁ , R ₂ , A, m, n, and R ₃ have the same meanings as above. A method of treating a compound represented by the following with an acid or alkali or reducing it. In the present invention, when carrying out the above method (A), the mercapto fatty acid of the formula () can preferably have its mercapto group protected with an appropriate protecting group that can be easily removed. . Examples of such protecting groups include, for example, acetyl group, benzoyl group, benzyloxycarbonyl group, p-methoxybenzyloxycarbonyl group, ethylcarbamoyl group, t-butoxycarbonyl group, benzyl group, p-methoxybenzyl group, p-nitrobenzyl group, benzhydryl group, di-p-methoxybenzhydryl group, trityl group, m-nitrophenyl phenacylmethyl group, benzylthiomethyl group, isobutyloxymethyl group, phenylthiomethyl group, acetamidomethyl and tetrahydropyranyl group. The reaction can be carried out using a reactive derivative of the mercapto fatty acid of the formula (), and examples of such reactive derivatives include active esters, acid anhydrides, acid halides, etc. of the mercapto fatty acid of the formula (). be able to. The reaction can also be carried out in the presence of a suitable activator, and when the reaction is carried out in the form of a mercapto fatty acid of formula (), it is particularly preferred to carry out the reaction in the presence of such an activator. Examples of such active esters include, for example, cyanomethyl ester of a compound of formula (), p
-Nitrophenyl ester, 2,4,5-trichlorophenyl ester, pentachlorophenyl ester, N-hydroxyphthalic acid imide ester, N-hydroxysuccinimide ester, 8
Examples include -hydroxyquinolyl ester, 2-hydroxyphenyl ester, 2-hydroxypyridyl ester, and 2-pyridylthiol ester. Preferably, the acid halides include acid chloride and acid bromide. Further, a preferable example of the activator is N,N-dicyclohexylcarbodiimide. The above-mentioned protecting group can be introduced by a method known per se. For example, active forms of compounds corresponding to these protecting groups, such as halides or acid halides, can be used, for example, in water, ether, benzene, methanol, ethanol, liquid ammonia, etc.
A solvent such as dimethylformamide or trifluoroacetic acid may be used alone or in combination, for example, in the presence or absence of an alkali such as sodium hydroxide, potassium hydroxide, potassium hydrogen carbonate, or an acid such as hydrobromic acid or hydrochloric acid. The reaction conditions can be appropriately selected depending on the characteristics of each protecting group, such as using a temperature range of -80°C to 90°C in the presence of the protective group. When carrying out method (A), the reaction temperature at which the aminocarboxylic acid derivative of formula () is reacted with the mercapto fatty acid of formula () or its reactive derivative in the presence or absence of an activating agent can be selected as appropriate. For example, the reaction temperature can be about -5°C to about 80°C, more preferably about 0°C to room temperature. The reaction can be carried out in a solvent if desired,
Examples of such solvents include ethers such as tetrahydrofuran and dioxane;
Esters such as ethyl acetate and isoamyl acetate;
For example, N,N-dimethylformamide, N-
N-alkylamides such as methyl-2-pyrrolidone and N,N-dimethylacetamide; other suitable solvents such as dimethyl sulfoxide, hexamethylphosphonylamide, and water may be used alone or in combination. The above formula () compound and formula () compound react stoichiometrically, but these two components do not necessarily have to exist in an equivalent relationship in the reaction system, and the quantitative ratio of the two components depends on the combination of raw materials. , can be appropriately selected depending on other conditions so as to obtain good results. In the condensation reaction between the above-mentioned compound of formula () and the compound of formula (), when a compound in which the mercapto group of the compound of formula () is a protected group as exemplified above is used, after the reaction, the mercapto group of the compound of formula () is protected. By removing the protecting group, the target compound of formula () can be obtained. The protective group can be removed by a known removal means, for example, by acid or alkali treatment or reduction treatment. For example, by treatment with metallic sodium in the presence of liquid ammonia, or in a liquid medium such as water, methanol, ethanol, acetic acid, an inorganic acid such as hydrochloric acid, hydrobromic acid, or , an alkali such as sodium hydroxide, potassium hydroxide, sodium carbonate, ammonia, methylamine, ethylamine, trimethylamine, hydrazine, hydrazine hydrate, sodium methylate, or a reducing agent such as sodium borohydride, e.g. ℃~about 80
It can be reacted and removed at temperatures such as °C. This reaction is preferably carried out under a nitrogen atmosphere or a hydrogen atmosphere. The mercapto fatty acid derivatives of the formula () of the present invention obtained as described above are neutralized if necessary,
Isolation or purification can be carried out by appropriately selecting or combining means known per se, such as extraction, dissolution, various chromatography, crystallization, recrystallization, and reprecipitation. The compound of formula () of the present invention thus obtained can form a salt with a base. Examples of such salts include ammonium salts, alkali metal salts such as sodium and potassium salts,
Examples of alkaline earth metal salts include calcium salts, magnesium salts, and amine salts. The salts of the formula () mercapto fatty acid derivatives of the present invention are preferably physiologically acceptable salts as exemplified above. In the present invention, when carrying out the method (B), the compound of formula () is reacted with a thio compound of formula () or an alkali metal salt thereof to form the compound of formula (), which is then acidified. Alternatively, R ₃ in formula () may be converted to a hydrogen atom by alkali treatment or reduction treatment. In this embodiment, the compound of the formula () used as the raw material compound in the above method (A) and the compound of the formula () below are used as the raw material compound in the method (A) above. However, R ₁ , X, and m have the same meanings as described above. X is preferably obtained by reacting with Cl or Br. This reaction can be carried out in the same manner as in method (A), in which the compound of formula () is reacted with the compound of formula (). When reacting a compound of formula () with a compound of formula (), benzene, toluene, dioxane, dimethylformamide, methylene chloride,
An appropriate solvent such as chloroform, ether, or water is used alone or in combination, and if necessary, in the presence of a deoxidizing agent such as sodium hydroxide, potassium hydroxide, sodium hydrogen carbonate, pyridine, dimethylaniline, triethylamine, etc. Approximately -5℃ to approximately 80℃
C., more preferably at a temperature of about 0.degree. C. to about room temperature. The compound of formula () thus obtained can be treated with an acid or an alkali, or subjected to reduction treatment to remove the R ₃ group to obtain the target compound of formula (). In this embodiment, the removal reaction of the R ₃ group is carried out by the above-mentioned A
In the method, when the mercapto group of the compound of formula () is protected, it can be carried out by the same method as that for removing the protecting group. Examples of R ₃ in compounds of formula () include alkanoyl groups such as acetyl, propionyl, butyryl; benzoyl, p-nitrobenzoyl,
Aroyl groups such as p-methylbenzoyl and p-chlorobenzoyl; N-methylcarbamoyl, N-
N-alkylcarbamoyl groups such as ethylcarbamoyl and N-propylcarbamoyl; N-arylcarbamoyl groups such as N-phenylcarbamoyl; N-alkylthiocarbamoyl groups such as N-methylthiocarbamoyl and N-ethylthiocarbamoyl; N such as ruthiocarbamoyl
-Arylthiocarbamoyl group; alkoxycarbonyl groups such as methoxycarbonyl, ethoxycarbonyl, and propoxycarbonyl; aryloxycarbonyl groups such as benzyloxycarbonyl and p-methoxybenzyloxycarbonyl; and the like. The mercapto fatty acid derivatives of the formula () of the present invention obtained by removing the R ₃ group from the compound of the formula () in this way are neutralized if necessary, and as in method A, the mercapto fatty acid derivatives of the present invention are prepared by means known per se, for example. , extraction, dissolution, various chromatography, crystallization, recrystallization, reprecipitation, and other means can be appropriately selected or combined for isolation or purification. Furthermore, if necessary, physiologically acceptable salts can also be produced in the same manner as in Method A. As described above, the target compound of the formula () which can be obtained, for example, by method (A) or method (B), has one atom when R ₁ is a hydrogen atom, and two atoms in other cases. It has an asymmetric carbon atom, which is shown in the above formula (). Therefore, the compound of the present invention () can exist as a diastereomer or a racemate, and in the present invention, the formula () is an expression that includes these. The compound of formula () of the present invention was tested for its enzyme inhibitory effect using angiotensin converting enzyme isolated from the lungs of domestic rabbits and using hyperlyl-L-histidyl-L-leucine as a substrate. showed that. Therefore, the compounds of the present invention are useful as agents for treating angiotensin-related hypertension. Example 1-1 N-(2-mercaptopropionyl)-D,L
-Production of methionine sulfone D,L-methionine sulfone 54.6g (0.3 mol)
was dissolved in 300 ml of 1N sodium hydroxide, and 75.0 g (0.35 mol) of α-bromopropionyl bromide was added.
and 350 ml of 1N sodium hydroxide were added dropwise alternately at 0 to 10°C while keeping the mixture slightly alkaline. After the dropwise addition was completed, the reaction was carried out at room temperature for 2 hours, then the mixture was made strongly acidic with hydrochloric acid while cooling, the resulting oil was extracted with ethyl acetate, the ethyl acetate layer was washed with water, dried over anhydrous sodium sulfate, and the solvent was distilled off to give a white color. Obtain crude crystals.
When this is recrystallized from ethyl acetate, 71.0 g (yield 75%) of N-(2-bromopropionyl)-D,L-methionine sulfone is obtained. Melting point 138-140
℃. 30.0g of N-(2-bromopropionyl)-D,L-methionine sulfone obtained here
(0.094 mol) is dissolved in 100 ml of dimethylformamide. Separately, 16.0 g (0.114 mol) of thiobenzoic acid
and 6.4 g (0.114 mol) of potassium hydroxide are dissolved in 50 ml of ethanol, and the resulting ethanol solution of potassium thiobenzoate is gradually added to the above solution.
After reacting for 4 hours at room temperature, insoluble matter was removed and the liquid was concentrated under reduced pressure to obtain a reddish-brown oil that was purified by silica gel chromatography. (Solvent: benzene-ethyl acetate) The resulting crude crystals were recrystallized from ethyl acetate to yield 14.8 g of N-(2-benzoylthiopropionyl)-D,L-methionine sulfone.
(Yield 36%) is obtained. Melting point 123-125℃. 7.4 g of N-(2-benzoylthiopropionyl)-D,L-methionine sulfone obtained here
(0.02 mol) was added with 20 ml of concentrated aqueous ammonia, and after reacting at room temperature for 2 hours, water was added and the by-produced benzamide was extracted with ethyl acetate. Hydrochloric acid is added to the aqueous layer to make it strongly acidic, and the resulting oil is extracted with ethyl acetate.
After washing with water and drying over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure and the resulting white crude crystals were recrystallized from ethyl acetate to yield N-(2-mercaptopropionyl).
-D,L-methionine sulfone 1.9g (yield 36%)
is obtained. Melting point 131-133℃. Infrared absorption spectrum IRν ^KBr _nax cm ^-1 3300 (NH) 2530 (SH) 1710 (COOH) 1650 (CONH) 1310 (SO ₂ )
1120 (SO ₂ ) Example 1-2 N-(2-mercaptopropionyl)-S-ethyl-L-cysteine sulfone In the same manner as in Example 1-1, S-ethyl- instead of D,L-methionine sulfone was used. Using L-cysteine sulfone, the title compound is obtained as colorless crystals. Melting point 98-102°C Example 1-3 N-(2-mercaptopropionyl)-D,L
- Ethionine sulfone In the same manner as in Example 1-1, the title compound is obtained as colorless crystals by using D,L-methionine sulfone instead of D,L-methionine sulfone. Melting point 135-140℃. Example 1-4 N-(2-mercaptopropionyl)-S-methyl-L-cysteine sulfone In the same manner as in Example 1-1, S-methyl-L-cysteine sulfone was used instead of D,L-methionine sulfone. The title compound is obtained as colorless crystals. Melting point 114-116℃. Example 1-5 N-(mercaptoacetyl)-D,L-methionine sulfone The title compound is obtained as colorless crystals in the same manner as in Example 1-1, using chloroacetyl chloride instead of α-bromopropionyl bromide. . Melting point: 121℃. Example 2-1 Production of N-(2-mercaptopropionyl)-S-methyl-L-cysteine 28.0 g (0.2 mol) of S-methyl-L-cysteine
was dissolved in 200 ml of 1N sodium hydroxide, and 50.0 g (0.24 mol) of α-bromopropionyl bromide was added.
and 240 ml of 1N sodium hydroxide are added dropwise alternately while keeping the mixture slightly alkaline at 0 to 10°C or below. After the dropwise addition was completed, the reaction was carried out at room temperature for 2 hours. After the reaction is complete,
In the same manner as in Example 1-1, N-(2-bromopropionyl)-S methyl-L-cysteine 24.0
g (yield 44%) is obtained. Melting point 97-99℃. 11.0 g of N-(2-bromopropionyl)-S-methyl-L-cysteine obtained here
(0.041 mol) in 50 ml of ethanol. Separately, 4.0 g (0.049 mol) of thioacetic acid and 2.7 g of potassium hydroxide
g (0.049 mol) is dissolved in 50 ml of ethanol, and the resulting ethanol solution of potassium thioacetate is gradually added to the above solution. After reacting overnight at room temperature, 8.6 g (yield 79%) of N-(2-acetylthiopropionyl)-S-methyl-L-cysteine was obtained as a light brown oil in the same manner as in Example 1-1. 8.5 g of N-(2-acetylthiopropionyl)-S-methyl-L-cysteine obtained here
(0.032 mol) was added with 20 ml of concentrated ammonia water and reacted at room temperature for 2 hours. The white oil obtained in the same manner as in Example 1-1 was recrystallized from ethyl acetate.
(2-mercaptopropionyl)-S-methyl-
2.5 g of L-cysteine (yield 35%) is obtained.
Melting point 71-72℃. Infrared absorption spectrum IR ^KBr-1 〓 _cn 3350 (NH) 2500 (SH) 1720 (COOH) 1620 (CONH) Example 2-2 N-(2-mercaptopropionyl)-S-ethyl-L-cysteine Example 2- In the same manner as in 1, S-methyl-L-
Using S-ethyl-L-cysteine instead of cysteine, the title compound is obtained as a colorless oil. Melting point of dicyclohexylamine salt 161-166
℃. Example 3-1 Production of N-(3-mercapto-2-methylpropionyl)-D,L-ethionine sulfone 19.5 g (0.1 mol) of D,L-ethionine sulfone
Dissolve in 100 ml of 1N sodium hydroxide, and add 26.7 g (0.11 mol) of 3-benzoylthio-2-methylpropionyl chloride and 1N sodium hydroxide.
Add 110 ml dropwise alternately at 0 to 10°C while keeping it slightly alkaline. After completion of the dropwise addition, the reaction was carried out at room temperature for 3 hours, then the mixture was made strongly acidic with hydrochloric acid while cooling, the resulting oil was extracted with ethyl acetate, the ethyl acetate layer was washed with water, dried over anhydrous sodium sulfate, and the solvent was distilled off to give a white crude product. Obtain crystals. When this is recrystallized from ethyl acetate, 24.4 g (yield: 61%) of N-(3-benzoylthio-2-methylpropionyl)-D,L-ethionine sulfone is obtained. Melting point: 123-125℃ N-(3-benzoylthio-2) obtained here
-Methylpropionyl)-D,L-ethionine sulfone 8.0g (0.02mol) and concentrated ammonia water 40ml
After reacting at room temperature for 3 hours, excess ammonia was distilled off under reduced pressure, and the by-produced benzamide was extracted with ethyl acetate. Add hydrochloric acid to the aqueous layer to make it strongly acidic.
The resulting oil is extracted with ethyl acetate, washed with water, dried over anhydrous sodium sulfate, the solvent is distilled off under reduced pressure, and the resulting white crude crystals are recrystallized from ethyl acetate.
-(3-mercapto-2-methylpropionyl)
-D,L-ethionine sulfone 4.9g (yield 82%)
is obtained. Melting point 111-116℃ Infrared absorption spectrum IRν ^KBr _nax cm ^-1 3310 (NH), 2550 (SH) 1720 (COOH), 1600 (CONH) 1300,
1260, 1120 (SO ₂ ) Example 3-2 N-(3-mercaptopropionyl)-D,L
-Ethionine sulfone The title compound is obtained as colorless crystals in the same manner as in Example 3-1, using 3-benzoylthiopropionyl chloride in place of 3-benzoylthio-2-methylpropionyl chloride. Melting point 121-122℃. Example 3-3 N-(3-mercaptopropionyl)-D,L
-Methionine sulfone In the same manner as in Example 3-1, instead of D,L-ethionine sulfone and 3-benzoylthio-2-methylpropionyl chloride, D,
The title compound is obtained as colorless crystals using L-methionine sulfone and 3-benzoylthiopropionyl chloride. Melting point 99-100℃. Example 3-4 N-(3-mercapto-2-methylpropionyl)-D,L-methionine sulfone In the same manner as in Example 3-1, D,L-methionine sulfone was used instead of D,L-ethionine sulfone. The title compound is obtained as colorless crystals. Melting point 116-118℃. Example 3-5 N-(3-mercaptopropionyl)-S-ethyl-L-cysteine sulfone D,L-ethionine sulfone and 3-benzoylthio-2-methylpropionyl chloride were prepared in the same manner as in Example 3-1. instead of S-, respectively.
The title compound is obtained as colorless crystals using ethyl-L-cysteine sulfone and 3-benzoylthiopropionyl chloride. Melting point 102-105℃. Example 3-6 N-(3-mercapto-2-methylpropionyl)-S-ethyl-L-cysteine sulfone In the same manner as in Example 3-1, S-ethyl- instead of D,L-ethionine sulfone was used. Using L-cysteine sulfone, the title compound is obtained as colorless crystals. Melting point 125-127℃. Example 4 N-(2-mercaptopropionyl)-D,L
-Production of methionine sulfone 1.1 g (0.0058 mol) of 2-(2-tetrahydropyranylthio)propionic acid) and 0.67 g (0.0058 mol) of N-oxysuccinimide were dissolved in 10 ml of methylene chloride, and 1.2 g of dicyclohexylcarbodiimide was added under ice cooling. (0.0058 mol) and stirred for 3 hours, then left in the refrigerator overnight. The resulting dicyclohexylurea is removed, and the filtrate is concentrated under reduced pressure. The residue was dissolved in 10 ml of ethyl acetate, and a solution of 0.72 g (0.004 mol) of D,L-methionine sulfone dissolved in 8 ml of 0.5N sodium hydroxide was added under ice cooling, and the mixture was stirred for 4 hours. The ethyl acetate layer is extracted with a 4% aqueous sodium bicarbonate solution, combined with the aqueous layer, made strongly acidic with hydrochloric acid, and extracted with ethyl acetate. The ethyl acetate layer was washed with water, dried over anhydrous sodium sulfate, the solvent was distilled off, the residue was dissolved in ethyl acetate, and dicyclohexylamine was added to precipitate white crystals of N-[2
A dicyclohexylamine salt of -(2-tetrahydropyranylthio)propionyl]-D,L-methionine sulfone is obtained. Melting point 165-168℃. When this dicyclohexylamine salt is treated with hydrochloric acid, the compound N-(2-mercaptopropionyl)-D,L-methionine sulfone of Example 1-1 is obtained. Example 5 N-(3-mercaptopropionyl)-D,L
-Manufacture of ethionine sulfone D,L-ethionine sulfone 5.9g (0.03 mol)
Dissolve in 60ml of 0.5N sodium hydroxide,
6.5 g (0.033 mol) of (N-ethylcarbamoylthio)propionyl chloride and 33 ml of 1N-sodium hydroxide are added dropwise alternately while keeping the mixture slightly alkaline at 0 to 10°C. After completion of the dropwise addition, the mixture was reacted overnight at room temperature, then made strongly acidic with hydrochloric acid while cooling, extracted with ethyl acetate, the ethyl acetate layer was washed with water, dried over anhydrous sodium sulfate, and the solvent was distilled off. Treatment of the residue with ether gives N-[3-(N-ethylcarbamoylthio)propionyl]-D,L-ethionine sulfone. The acid obtained here is 3N-sodium hydroxide 30
After stirring at room temperature for 3 hours, the reaction solution was washed with ether, made strongly acidic with hydrochloric acid, the resulting oil was extracted with ethyl acetate, washed with water, dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure. The white crystals obtained are recrystallized from ethyl acetate to obtain N-(3-mercaptopropionyl)-D,L-ethionine sulfone. Melting point 121-122℃ Infrared absorption spectrum IRν ^KBr _nax cm ^-1 3310 (NH), 2550 (SH) 1690 (COOH), 1635 (CONH) 1305,
1260,1105 (SO ₂ ) Example 6 Dicyclohexylamine salt of N-(3-mercapto-2-methylpropionyl)-D,L-ethionine sulfone N-(3-mercapto- obtained in Example 3-1) Dissolve 300 mg of 2-methylpropionyl)-D,L-ethionine sulfone in ethyl acetate, add 200 mg of dicyclohexylamine, and heat. After cooling, the precipitated white crystals were collected by filtration, and the title compound 400
mg is obtained. Melting point 150-153°C Example 7 N-(3-mercaptopropionyl)-D,L
- Potassium salt of ethionine sulfone 280 mg of N-(3-mercaptopropionyl)-D,L-ethionine sulfone obtained in Example 5
A solution of 180 mg of potassium 2-ethylhexanoate in ethyl acetate is added to the ethyl acetate solution and stirred.
Ether is added to the resulting oil, which is washed with ether and then with hexane, and then dried under reduced pressure to obtain the title compound. Reference example: Test for angiotensin converting enzyme inhibitory effect Angiotensin converting enzyme (ACE) inhibitory effect was tested by Cushman and Cheung [Biochem.
Pharmacol., 20, 1637 (1971)] using ACE isolated from rabbit lungs.
The measurement was performed as follows using L-histidyl-L-leucine as a substrate. Measurement method Hyperyl-L-histidyl-L-leucine (substrate) was dissolved in 0.1M potassium phosphate buffer (PH8.3) to prepare a 12.5mM substrate solution. In addition, test compounds were dissolved in the same buffer solution to prepare test solutions of various concentrations. Angiotensin converting enzyme (ACE) solution purified from rabbit lung (activity: 1.34μ/ml)
is diluted with a similar buffer and its absorbance value is approximately
Adjusted to 0.4 (oxygen liquid). Mix 0.10ml of test solution and 0.05ml of enzyme solution, preincubate at 37℃ for 5 minutes, and then add 0.10ml of substrate solution.
was added and incubated at 37°C for 30 minutes. Next, 0.25 ml of 1N hydrochloric acid was added under ice cooling to stop the reaction, and after the reaction, 1.5 ml of ethyl acetate was added, stirred for 15 seconds, centrifuged, and 1 ml of the ethyl acetate layer was separated. The ethyl acetate layer was evaporated to dryness, and hippuric acid produced from the substrate by the action of angiotensin converting enzyme was obtained. After adding 1 ml of 1M sodium chloride to this and stirring for 15 seconds, ultraviolet absorption at 228 nm was measured. Control samples with enzyme activity of 0% and 100% were operated in the same manner, and compared with this, the inhibition rate of the test solution at each concentration was calculated, and from the relationship between concentration and inhibition rate, the inhibitory effect of each compound on the enzyme was evaluated. The concentration that inhibits the activity of 50% (IC ₅₀ ) is shown in the table below. As shown in the results, all the compounds of the present invention have excellent angiotensin converting enzyme inhibitory activity.

[Table] ｜

COOH

[Table] ｜

COOH

[Table] The renin-angiotensin-aldosterone system is a hormonal system that plays an important role in regulating blood pressure. Angiotensin produced by renin is biologically almost inactive, but angiotensin produced by angiotensin converting enzyme (ACE) is the most powerful pressor substance in the body, directly or by stimulating the vasomotor center and secreting catecholamines. Acts indirectly on vasoconstriction through promotion.
It also stimulates aldosterone secretion and the lip brown center to increase body fluid volume, both of which ultimately have a pressor effect. Therefore, drugs that inhibit ACE can be used as therapeutic agents for hypertension.

Claims (1)

[Claims] 1 The following formula () In the formula, R ₁ represents a hydrogen atom or a lower alkyl group, R ₂ represents a lower alkyl group, A represents S or SO ₂ , m represents 0 or 1, n represents 1 or 2, * A marked carbon atom indicates an asymmetric carbon atom, and a marked ** carbon atom indicates an asymmetric carbon atom when R ₁ is a lower alkyl group, provided that A is S and And when n=2, R ₂ is
Mercapto fatty acid derivatives and salts thereof represented by the following, which represent a group other than CH ₃ .