JPH0564946B2 - - Google Patents

Description

[Detailed description of the invention]

(1) Purpose of the invention [Field of industrial application] The purpose of the present invention is to develop a general formula useful as a pharmaceutical product. (In the formula, R ¹ is a carbamoyl group or a lower alkoxycarbonyl group, His is an L-histidyl group, n is 0 or 1, and Y is -0-
or -NH-, and ^R2 is a linear or branched alkyl group having 1 to 7 carbon atoms) and pharmacologically acceptable acid addition salts thereof. It is to be.
More specifically, human renin (human
An object of the present invention is to provide novel amino acid derivatives represented by the above general formula and pharmacologically acceptable acid addition salts thereof, which have an inhibitory effect on (renin) and are useful as orally administrable therapeutic agents for hypertension. [Prior Art] Renin is a proteolytic enzyme released from juxtaglomerular cells of the kidney. This reacts with the renin substrate present in the alpha ₂ globulin fraction of plasma to produce angiotensin. The generated angiotensin is converted to angiotensin by angiotensin converting enzyme.
) is converted to This angiotensin has a vasoconstrictive effect and acts on the adrenal cortex,
It is a factor in hypertension that causes the secretion of aldosterone, which affects sodium and water metabolism. Compounds that inhibit the reaction between renin and renin substrates and suppress the production of angiotensin are attracting attention as antihypertensive agents with a new mechanism of action, and their development is strongly desired. Until now, many peptide derivatives have been known as compounds that inhibit the reaction between renin and renin substrates, that is, have the effect of inhibiting renin activity (Japanese Patent Publication No. 58-39149, Japanese Patent Publication No. 1983 -No. 110661, No. 155345, No. 155345, No. 15534-
No. 227851, European Patent Publication No. 707029,
(No. 77028, No. 81783) Among these patent applications, in particular, Japanese Patent Publication No. 155345 (1983) contains the general formula (A in the formula is a hydrogen atom, a phenyl group, 10, 11-
dihydro-5H-dibenzo[a,d]cycloheptenyl group, etc., and B is -0-, -CH=CH
-, -CH ₂ -, etc., p and q may be the same or different and each is an integer of 0 or 1 to 3, and D is a hydrogen atom, a lower alkyl group, a lower alkenyl group, phenyl group, phenylalkyl group, etc., E is phenyl group, cyclohexyl group, isopropyl group, etc., His is L-histidyl group, F is an amino acid residue, for example, L-leucyl group, L-isoleucyl group, L-leucyl-L-phenylalanyl group, L-phenylalanyl-L-phenylalanyl group, L-alanyl-L-phenylalanyl group, etc., and G is a protecting group at the C-terminus of the amino acid, such as an amino group, alkylamino The present disclosure discloses peptide derivatives represented by a group such as a group, an arylalkyl amino group, an alkoxy group, etc. Also, in Japanese Patent Publication No. 59-227851,
general formula (R ³ CO- in the formula is an acyl group of an N-substituted amino acid, such as benzyloxycarbonyl group, t-butoxycarbonyl group, α-naphthoxyacetyl group, phenylbutyryl group, 3-(3-nitro-2
-pyridine sulfenyl)thiopropionyl group,
Amino acids whose amino groups are substituted with 9-fluorenylmethyloxycarbonyl groups, such as L-phenylalanyl groups, L-tryptopyl groups, L-
Tyrosyl group, L-cystyl group, 3-(1-naphthyl)-L-alanyl group, L-phenylglycyl group,
1-amino-4-phenylbutyryl group, 1,2,
3,4-tetrahydro-β-carboline-3-L
- carboxyl group, etc., His is an L-histidyl group, (S)C indicates an S configuration, R ⁴ is a hydroxyl group,
A mercapto group or a formyl group, and R ⁵ is a hydrogen atom, an alkyl group, or a substituted alkyl group having a hydroxyl group, a mercapto group, an amino group, a carbamoyl group, a formyl group, an aryl group, or a heterocyclic group as a substituent. discloses a peptide derivative represented by [Problem to be solved by the invention] Most of the compounds disclosed in the above-mentioned patent applications are polypeptides, which are difficult to synthesize.
Moreover, it is degraded by proteolytic enzymes in the body, such as chymotrypsin, and cannot be expected to exert its pharmacological effects when administered orally. The peptide derivative represented by the above general formula () is a tri- or tetra-peptide derivative, and although it is relatively easy to produce compared to other polypeptide derivatives, this compound is also a polypeptide derivative as disclosed in the above-mentioned patent application. Like peptide derivatives, it is unstable to proteolytic enzymes, and it is difficult to expect that it will exhibit its medicinal efficacy when administered orally. Furthermore, although the compound represented by the above formula () is easier to produce than other peptide derivatives, this compound is also resistant to proteolytic enzymes, similar to the polypeptide derivatives disclosed in the above-mentioned patent applications. It is stable and it is difficult to expect that it will exhibit its medicinal efficacy through oral administration. As a result of various studies aimed at solving these problems, the present inventors have found that the amino acid derivatives represented by the above general formula () and their pharmacologically acceptable acid addition salts can be produced relatively easily. The inventors have discovered that the drug has a strong renin activity inhibiting effect, has low toxicity, can be administered orally, and can solve the above-mentioned problems. (2) Structure of the invention [Means and effects for solving the problems] The amino acid derivatives of the present invention represented by the general formula () and their pharmacologically acceptable acid addition salts are human renin-sheep renin substrates. It exhibits a strong renin activity inhibitory effect in both human and high-renin plasma, and is stable against proteolytic enzymes such as chymotrypsin and pepsin. Additionally, this product exhibits a clear hypotensive effect when injected orally or intravenously in monkeys with high renin status. This indicates that the amino acid derivatives of the present invention represented by the general formula () and their pharmacologically acceptable acid addition salts have a strong renin activity inhibiting effect, and can be orally administered with low toxicity for the treatment of hypertension. This indicates that it is useful as a drug. The amino acid derivative of the present invention represented by the general formula () is represented by the general formula (R ¹ in the formula has the same meaning as above) and the general formula (In the formula, (L) C indicates an L-configuration, X indicates an acid residue, and Y and R ² have the same meanings as above) are condensed using diphenyl phosphoryl azide. It can be manufactured by The carboxylic acid represented by the general formula () used as a starting material in this reaction can be produced by a method described in the literature or a method similar thereto. For example, by reacting 1-naphthaldehyde with diethyl succinate and then hydrolyzing it with sodium hydroxide, the formula A compound represented by is obtained, which is ring-closed with acetic anhydride to give the formula A succinic anhydride derivative represented by is obtained. By reacting the succinic anhydride derivative of this formula () with ammonia or lower alcohols, the formula It can be produced by obtaining a compound represented by (R ¹ in the formula has the same meaning as above) and hydrogenating this in the presence of palladium on carbon. The compound of the general formula () used as the other starting material in the production method of the present invention can be obtained by reacting L-histidine methyl ester whose amino group is protected with an appropriate protecting group with hydrazine in a methanol solution. A compound represented by (in the formula, Z is a protecting group for an amino group, and (L)C has the same meaning as above) is obtained.
After reacting this compound with isoamyl nitrite,
general formula It can be produced by reacting with a compound represented by the formula (in which n, Y and R ² have the same meanings as above) and then removing the protecting group. The compound represented by the general formula () can be produced by a method described in the literature or a method similar thereto. For example, in the compound of general formula (), n is 0
The compound is described in The Journal of Organ Chemistry [J.Org.Chem.] Volume 45,
Pages 2288-2290 (1980), Chemical and Pharmaceutical Bulletin [Chem.
3-Amino-2-hydroxy-5-methylhexanoic acid was obtained by a method similar to that described in Pharm.Bull] Vol. 16, pages 492-497 (1968) and Vol. , is produced by esterifying or amidating this in a conventional manner. Further, the compound of general formula () in which n is 1 is, for example, statin or N-
It is produced by esterifying or amidating (tert-butyloxycarbonyl)statin using a conventional method. The reaction between the compound represented by the general formula () of the present invention and the compound represented by the general formula () can be carried out according to a conventional method. To suitably carry out this reaction, a compound represented by the general formula () and an equimolar amount of the compound represented by the general formula () are dissolved in N,N-dimethylformamide, and the mixture is stirred under ice cooling. Add diphenyl phosphate azide and triethylamine and stir overnight. The target product can be obtained by treating and purifying the reaction product according to conventional methods. The amino acid derivative of the present invention represented by the general formula ( exists. Although the configuration of substituents on these asymmetric carbon atoms affects the renin inhibitory activity of the compound represented by the general formula (), in the present invention, the configuration of substituents on these isomers other than the L-histidine moiety There are no particular limitations on the steric configuration of carbon. In the amino acid derivative represented by the general formula () of the present invention, the configuration of the carbon atom substituted with the amino group in the compound moiety represented by the general formula () is preferably the S configuration. Furthermore, the steric configuration of the carbon atom on which the hydroxyl group is substituted also affects the activity, and the R configuration is preferred, but a mixture of the S configuration and the R configuration may be used. The steric structure of the carboxylic acid represented by the general formula () also affects the renin inhibitory activity of the compound represented by the general formula () of the present invention to some extent. In this acyl moiety, strong inhibitory activity is observed in either the S configuration or the R configuration of the carbon atom substituted with the α-naphthylmethyl group, but a mixture thereof may be used. The optically active starting materials used in the production of such optically active compounds are optically resolved by conventional methods, or
Alternatively, it is produced using an optically active compound. For example, the configuration of the carbon atom substituted with the amino group of the compound represented by the general formula () is S
Compounds of the configuration are prepared by using L-leucine or statins. The compound represented by the general formula () of the present invention can be converted into a pharmacologically acceptable acid addition salt according to a conventional method, and examples of these salts include hydrochloride, sulfonate, and p-toluenesulfonic acid. salt, acetate,
Examples include citrate. These acid addition salts also have a strong renin activity inhibiting effect, are stable to proteolytic enzymes, and clearly lower blood pressure in monkeys with high renin status when orally administered. The amino acid derivative represented by the general formula () and its pharmacologically acceptable acid addition salt of the present invention can be made into a pharmaceutical composition according to a conventional method. Examples of such pharmaceutical compositions include tablets, capsules, granules, and injections. The amino acid derivatives and pharmacologically acceptable acid addition salts represented by the general formula () have a strong renin activity inhibitory effect, and the 50% inhibitory activity value ( IC ₅₀ ) were 5.2×10 ^-7 to 2.5×10 ^-8 molar concentration and 6.9×10 ^-7 to 5.6×10 ^-8 molar concentration, respectively, which clearly lowered the blood pressure of common marmosets in a high renin state. and has low toxicity. When a pharmaceutical composition containing an amino acid derivative represented by the general formula () or a pharmacologically acceptable acid addition salt thereof is used for treatment, the dosage is determined based on the severity of the disease, the sex, age, and weight of the patient. However, for oral administration, the dose is generally 5mg to 5000 per day for adults.
mg, and parenteral administration can be administered within the range of 1 mg to 1000 mg per day. [Example] In order to further explain the present invention in detail, reference examples and examples are given below. Note that the melting points of the compounds in each Reference Example and Examples are uncorrected. In addition, the NMR spectra of each compound are JEOL JNM-
Measurements were made using a GX270 high-resolution nuclear magnetic resonance apparatus. Mass spectrum is JEOL JMS-DX300
It was measured by the FAB method using a model mass spectrometer. Thin layer chromatography is performed using Merck's precoated plate silica gel.
Column chromatography was performed using Merck's Kieselgel ₆₀ (230-400 mesh). In addition, the developing solvent for thin layer chromatography is the lower layer of a mixture of chloroform/methanol/water = 8/3/1 and the lower layer of a mixture of chloroform/methanol/water = 8/3/1.
Rf values (Rf ₁ and Rf ₂ ) were calculated using two types of 5/1 mixed liquids. Reference example 1 3-(methoxycarbonyl)-2-(1-naphthylmethyl)propionic acid 32.3 g of ethyl succinate and 1-naphthaldehyde
Dissolve 29.0 g in 320 ml of absolute ethanol, add 10.7 g of 50% sodium hydride (oil-based) under ice cooling, and heat under reflux for 30 minutes. Add 230 ml of 1N aqueous sodium hydroxide solution to this solution, and heat under reflux for 1 hour. The solvent is distilled off under reduced pressure, water is added to the residue, the neutral part is extracted and removed with ether, the aqueous layer is acidified with concentrated hydrochloric acid, and extracted with ether.
After washing the ether layer with saturated brine, it is dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, benzene was added to the residue, and the precipitated crystals were collected by filtration to obtain 26.5 g of 2-(1-naphthylmethylene)succinic acid as yellow crystals. 2-(1-naphthylmethylene)succinic acid 24.5g
Add 260 ml of acetic anhydride to the mixture and heat at 60°C for 1 hour.
The solvent was distilled off under reduced pressure, a mixed solution of benzene/hexane = 1/1 was added to the residue, and the precipitated crystals were collected by filtration.
16.0 g of 2-(1-naphthylmethylene)succinic anhydride is obtained as orange-yellow crystals. 2-(1-naphthylmethylene)succinic anhydride 300
Dissolve mg and 18 ml of methanol in 30 ml of dry methylene chloride and heat under reflux for 5 hours. The solution is washed with dilute hydrochloric acid and water, and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure to obtain 3-methoxycarbonyl-2-(1-naphthylmethylene) as a white powder.
Obtain 336 mg of propionic acid. This propionic acid 251
Dissolve mg in 10 ml of methanol, add 30 mg of 10% palladium on carbon, and hydrogenate at normal pressure. After filtering off the catalyst, the solvent was distilled off under reduced pressure to obtain 250 mg of 3-methoxycarbonyl-2-(1-naphthylmethyl)propionic acid in the form of a white powder. Rf ₁ : 0.68 Melting point: 111-112°C IR (KBr): νco 1730, 1690 cm ^-1 Reference Example 2 The following carboxylic acid was synthesized in the same manner as in Reference Example 1. 3-(isopropoxycarbonyl)-2-(1-
Naphthylmethyl)propionic acid White powder Rf ₁ : 0.63 Melting point: 39-43℃ IR (KBr): νco 1710 cm ^-1 3-(Carbamoyl)-2-(1-naphthylmethyl)propionic acid Rf ₁ : 0.42 Melting point : 179-181℃ IR (KBr): νco 1700, 1640 cm ^-1 Reference example 3 (2RS, 3S)-3-amino-2-hydroxy-
Isopropyl 5-methylhexanoate hydrochloride 10 g of N-carbobenzoxy-L-leucine is dissolved in 60 ml of dry tetrahydrofuran, the mixture is cooled to -15°C (internal temperature) and 6.8 ml of dry triethylamine are added. 4.8 chloroethyl carbonate under stirring
A solution of 10 ml of dry tetrahydrofuran was added dropwise while maintaining the internal temperature of -10 to -15°C, and the mixture was stirred for 1 hour. The precipitated triethylamine hydrochloride is quickly filtered off to obtain a reaction solution. Meanwhile, dissolve 5.8 g of sodium borohydride in 80 ml of water/tetrahydrofuran (1:1) mixed solvent and stir vigorously at 15 to 20°C (internal temperature), and add the previous reaction solution to this solution for about 30 minutes. Add the mixture dropwise and stir for 1 hour. The organic layer of the reaction solution is separated, ethyl acetate is added thereto, the solution is washed with a saturated aqueous sodium bicarbonate solution and saturated brine, dried over magnesium sulfate, and the solvent is distilled off under reduced pressure. The residual oil was purified by silica gel column chromatography (elution solvent: chloroform/methanol = 20/1) to obtain 6.7 g of N-carbobenzoxy-L-leucinol. N-carbobenzoxy-L-leucinol 6.68
g and 18.5 ml of dry triethylamine in dry benzene
Dissolve in 10ml (solution A). Meanwhile, a solution of 11.8 ml of dry pyridine and 18.9 ml of dry dimethyl sulfoxide was mixed with 5.4 ml of anhydrous sulfuric acid under stirring under ice cooling.
ml (solution B). After cooling Solution B to 20-25°C, Add Solution A dropwise and stir for 10 minutes. Pour the reaction solution into water and add ethyl acetate. The ethyl acetate layer was separated, washed with a saturated aqueous sodium bicarbonate solution and water, dried over magnesium sulfate, and the solvent was distilled off under reduced pressure to obtain 6.16 g of N-carbobenzoxy-L-leucinal. N-carbobenzoxy-L-leucinal 2.81
A solution of 3.43 g of sodium bisulfite in 20 ml of water was added to the mixture, and the mixture was stirred for 14 hours under ice cooling. Add a solution of 1.41 g of potassium cyanide to 50 ml of water and ethyl acetate to this reaction solution.
Add 200ml and stir at room temperature for 4 hours. After washing the ethyl acetate layer with saturated brine, it is dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure to obtain 2.54 g of 3-carbobenzoxyamino-2-hydroxy-5-methylhexanenitrile as a colorless oil. Add 50ml of 23% hydrochloric acid to 2.5g of this nitrile,
Heat to reflux for an hour. The reaction solution was washed with benzene, and the aqueous layer was concentrated under reduced pressure to obtain a white powder (2RS, 3S)-
1.6 g of 3-amino-2-hydroxy-5-methylhexanoic acid (a mixture with a ratio of 2R:2S of approximately 7:3) is obtained. Next, 1.6 g of (2RS,3S)-2-amino-2-hydroxy-5-methylhexanoic acid is dissolved in 12 ml of isopropanol, hydrogen chloride gas is blown in while stirring under ice cooling, and 25 ml of dry benzene is added to produce a solution. Heat to reflux for 10 minutes while removing water.
The reaction solution was concentrated to dryness under reduced pressure, and the residue was purified by silica gel column chromatography (elution solvent: chloroform/methanol = 15/1), acidified with hydrochloric acid, and then concentrated to dryness to obtain a white powder ( 2RS,
0.55 g of isopropyl 3S)-3-amino-2-hydroxy-5-methylhexanoate hydrochloride is obtained. IR (KBr): νco 1725 cm ^-1 NMR (D ₂ O) δ: 0.8 to 1.1 (m, 6H), 1.29 (d, 6H, J = 6.6
Hz), 1.5-2.0 (m, 3H), 3.6-3.75 (m,
1H), 4.3-4.7 (m, 1H), 5.0-5.2 (m, 1H) Reference example 4 Statylisoamylamide hydrochloride 100 mg of N-(tert-butyloxycarbonyl)statin (commercially available) and 42 mg of isoamylamine were added to 3 ml of tetrahydrofuran. and N,N-dimethylformamide, 79 mg of 1-hydroxybenzotriazole was added thereto, followed by 83 mg of dicyclohexylcarbodiimide under ice-cooling and stirring.
Stir for an hour. After filtering off the precipitated crystals, the solvent was distilled off under reduced pressure, ethyl acetate was added to the residue, and after cooling on ice, the precipitated crystals were filtered off. The ethyl acetate layer was washed with a 5% aqueous sodium bicarbonate solution and saturated brine, and then dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the residue was purified by silica gel flash column chromatography (elution solvent: chloroform/methanol = 40/1) to obtain N-(tert-butyloxycarbonyl)statyl as a colorless viscous oil. Obtain 125 mg of isoamylamide. [IR (liquid film): νco 1685, 1640 cm ^-1 ] Dissolve 120 mg of this amide in 5 ml of methanol,
Add 3.6 ml of 2N hydrochloric acid and heat at 60°C for 1 hour.
The solvent was distilled off under reduced pressure to obtain 112 mg of statyl isoamylamide hydrochloride as a colorless viscous oil. [IR (liquid film): νco 1640cm ^-1 ] Reference Example 5 The following amide was synthesized in the same manner as in Reference Example 4. (2RS,3S)-3-amino-2-hydroxy-
5-Methylhexanoic acid isoamylamide hydrochloride White powder IR (KBr): νco 1640 cm ^-1 Reference example 6 (2RS,3S)-3-(L-histidyl)amino-
Isopropyl 2-hydroxy-5-methylhexanoate dihydrochloride L-histidine methyl ester dihydrochloride 10.0g
was suspended in 200 ml of dry chloroform, 18.4 ml of triethylamine and 10.2 g of 4-methoxybenzyloxycarbonyl azide were added under cooling, and the mixture was stirred at 0°C for 16 hours. The solvent was distilled off under reduced pressure, and the residue contained 5%
Add an aqueous sodium bicarbonate solution, extract with ethyl acetate, wash with water, and dry over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the residue was subjected to silica gel flash column chromatography (elution solvent: chloroform/methanol = 10/1).
to obtain 11.0 g of N-(4-methoxybenzyloxycarbonyl)-L-histidine methyl ester as a yellow oil. Dissolve 10.9 g of this ester in 112 ml of methanol, and dissolve 9.9 ml of hydrazine monohydrate.
and stirred at room temperature for 4 hours. The solvent was distilled off under reduced pressure, the residue was washed with ethanol, and then the residue was removed under reduced pressure.
Drying at 40° C. or below yields 4.9 g of N-(4-methoxybenzyloxycarbonyl)-L-histidine hydrazide in the form of a white powder. 485 mg of this hydrazide was suspended in 5 ml of N,N-dimethylformamide, and mixed with 5.1N dry hydrogen chloride/N,N-dimethylformamide while stirring at -20°C.
Add 0.90ml followed by 0.23ml isoamyl nitrite. After confirming the disappearance of hydrazide, the temperature of the reaction solution was lowered to -30°C and neutralized with 0.67 ml of triethylamine to prepare a cold solution of N-(4-methoxybenzyloxycarbonyl)-L-histidine azide. Separately (2RS,3S)-3-amino-2-hydroxy-5-methylhexanoic acid isopropyl hydrochloride
350 mg and 0.46 ml of triethylamine dry N,N-
The cold azide solution was added dropwise to 8 ml of dimethylformamide solution under ice cooling, and the mixture was stirred for 16 hours. The solvent was distilled off under reduced pressure, 5% aqueous sodium bicarbonate solution was added to the residue, extracted with ethyl acetate, washed with saturated brine, and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the residue was purified by silica gel flash column chromatography (elution solvent: chloroform/methanol = 20/1) to obtain a white powder (2RS,3S)-3-[N- (4-
325 mg of isopropyl (methoxybenzyloxycarbonyl)-L-histidyl]amino-2-hydroxy-5-methylhexanoate are obtained. Dissolve 320 mg of this isopropyl hexanoate in 20 ml of methanol, add 2.6 ml of 2N hydrochloric acid and 10% palladium on carbon.
Add 48 mg and hydrogenate at normal pressure. After removing the catalyst by filtration, the solvent was distilled off under reduced pressure to obtain white powder (2RS, 3S).
-3-(L-histidyl)amino-2-hydroxy-5-methylhexanoate isopropyl dihydrochloride
Get 275mg. Rf ₁ : 0.09 IR (KBr) : νco 1720, 1680 cm ^-1 Reference Example 7 The following amino acid derivative was synthesized in the same manner as in Reference Example 6. (2RS,3S)-3-(L-histidyl)amino-
2-Hydroxy-5-methylhexanoic acid isoamylamide dihydrochloride White powder Rf ₁ : 0.16 IR (KBr): νco 1660 cm ^-1 L-Histidyl-statyl isoamylamide 2
Hydrochloride White powder Rf ₁ : 0.29 IR (KBr): νco 1680 cm ^-1 Example 1 (2RS, 3S)-3-[3-(methoxycarbonyl)
-2-(1-naphthylmethyl)propionyl-
L-histidyl]amino-2-hydroxy-5
-Isopropyl methylhexanoate 28 mg of 3-methoxycarbonyl-2-(1-naphthylmethyl)propionic acid and (2RS,3S)-3-
(L-histidyl)amino-2-hydroxy-5
- Dissolve 50 mg of isopropyl methylhexanoate dihydrochloride in 3 ml of N,N-dimethylformamide, add 0.026 ml of diphenylphosphoric acid azide and 0.046 ml of triethylamine while stirring on ice, and stir overnight. The solvent was distilled off under reduced pressure, and the residue was
% aqueous sodium bicarbonate solution and extracted with ethyl acetate. After washing with water, it is dried over anhydrous magnesium sulfate, and the solvent is distilled off under reduced pressure. The residue was purified by silica gel column chromatography (elution solvent: chloroform/methanol = 20/1) to obtain a white powder of (2RS,3S)-3-[3-(methoxycarbonyl)-2-(1-naphthyl). methyl)propionyl-L-histidyl]amino-2-hydroxy-
20 mg of isopropyl 5-methylhexanoate is obtained. Melting point: 75-78°C Rf ₁ : 0.58 Rf ₂ : 0.52 M S: MH ⁺ , 595 Example 2 The following compound was synthesized in the same manner as in Example 1. (2RS, 3S)-3-{N-[3-(carbamoyl)
-2-(1-naphthylmethyl)propionyl]-
L-histidyl}amino-2-hydroxy-5
-Isopropyl methylhexanoate White powder Melting point: 96-102℃ Rf ₁ : 0.59 Rf ₂ : 0.52 M S: MH ⁺ , 580 (2RS, 3S) -3-{N-[3-(isopropoxycarbonyl)-2 -(1-naphthylmethyl)propionyl]-L-histidyl}amino-2-hydroxy-5-methylhexanoate isopropyl White powder Melting point: 72-75℃ Rf ₁ : 0.69 Rf ₂ : 0.69 M S: MH ⁺ , 623 Example 3 N-[3-(methoxycarbonyl)-2-(1-naphthylmethyl)propionyl]-L-histidyl-statylisoamylamide 3-(methoxycarbonyl)-2-(1-naphthylmethyl)propionic acid 16 mg and L-histidyl-
Statylisoamylamide dihydrochloride 27mg N,N
-Dissolve in 3 ml of dimethylformamide, add 0.015 ml of diphenylphosphoric acid azide and 0.027 ml of triethylamine while stirring on ice, and stir overnight. The solvent was distilled off under reduced pressure, a 5% aqueous sodium hydrogen carbonate solution was added to the residue, and the mixture was extracted with ethyl acetate. The extract is washed with water, dried over anhydrous magnesium sulfate, and the solvent is distilled off under reduced pressure. The residue was subjected to preparative silica gel thin layer chromatography (developing solvent: chloroform/methanol = 5/1).
Then, the part corresponding to Rf ₂ of 0.66 was isolated and purified to obtain white powdery N-[3-methoxycarbonyl-2-
10 mg of (1-naphthylmethyl)propionyl]-L-histidyl-statylisoamylamide are obtained. Melting point: 70-74°C Rf ₁ : 0.65 Rf ₂ : 0.65 M S: MH ⁺ , 636 Example 4 The following compound was synthesized in the same manner as in Example 3. (2RS,3S)-3-[3-methoxycarbonyl-
2-(1-naphthylmethyl)propionyl-L
-Histidyl]amino-2-hydroxy-5-
Methylhexanoyl isoamylamide Melting point: 72-75°C Rf ₁ : 0.61 Rf ₂ : 0.53 M S: MH ⁺ , 622 Example 5 Inhibition of renin activity on human renin-sheep renin substrate 125mM pyrophosphate at PH7.4 200μ of pyrophosphate buffer and 20mM aqueous solution of L-phenylalanyl-L-alanyl-L-proline as angiotensin converting enzyme inhibitor
25μ, 50μ of partially purified sheep renin substrate containing 2000 ng angiotensin equivalents/ml, 150μ of deionized water and 50μ of a dimethyl sulfoxide solution of the compound of the invention.
Or as a control group, 25μ of purified human renin at 20-30ng angiotensin/ml/hour was added to a solution of 50μ of dimethyl sulfoxide.
Incubate for 15 minutes in a water bath at °C.
Thereafter, the reaction solution was placed in a 100°C water bath for 5 minutes to stop the reaction. After cooling, collect 200μ,
The amount of angiotensin produced by the addition of renin was determined by radioimmunoassay.
The inhibitory activity was determined using the following formula. Inhibitory activity (%) = control value - value in the presence of the compound of the present invention / control value x 100 The 50% inhibitory activity molar concentration (IC ₅₀ ) was determined from the inhibitory activity determined by the above formula, and the results are shown in Table 1. show. The meaning of each symbol is as follows.

[Table] Example 6 Inhibitory effect on renin activity in human high-renin plasma 14mMEDTA 2 in 500μ of human high-renin plasma
0.5M of PH7.0 containing Na and 0.3% neomycin sulfate
Phosphate buffer 350μ, 20mM L as angiotensin converting enzyme inhibitor
Add 50 .mu. of an aqueous solution of -phenylalanyl-L-alanyl-L-proline and 100 .mu. of a solution of the compound of the invention in dimethyl sulfoxide or 100 .mu. of dimethyl sulfoxide as a control group. Of this reaction solution, 200μ is placed in an ice bath at 4°C, and the remaining 800μ is incubated in a water bath at 37°C for 60 minutes. Aliquot 200μ of the reaction solution incubated at 37°C, immediately cool it on ice, and quantify the amount of angiotensin by radioimmunoassay along with the reaction solution incubated in an ice bath. Plasma renin activity is calculated by subtracting the amount of angiotensin in the reaction solution incubated at 4°C from the amount of angiotensin in the reaction solution incubated at 37°C. Inhibitory activity (%) was determined by the following formula. Inhibitory activity (%) = control value - value in the presence of the compound of the present invention / control value x 100 The 50% inhibitory activity molar concentration (IC ₅₀ ) was determined from the inhibitory activity determined by the above formula, and the results are shown in Table 2. show. The meaning of each symbol is as follows.

〔Effect of the invention〕

The amino acid derivatives represented by the general formula () and their pharmacologically acceptable acid addition salts of the present invention have a 50% inhibitory activity value (IC ₅₀ ) of 5.2 in a renin activity inhibition test using a human renin-sheep renin substrate system. ×
10 ^-7 to 2.5 x 10 ^-8 molar concentration, and also 50% in renin inhibition test in human high renin plasma.
It exhibits a strong inhibitory effect on renin activity with an inhibitory activity value (IC ₅₀ ) of 6.9×10 ⁻⁷ to 5.6×10 ⁻⁸ molar concentration, and has low toxicity. Furthermore, the amino acid derivatives represented by the general formula () and their pharmacologically acceptable acid addition salts of the present invention are stable against proteolytic enzymes such as chymotrypsin and pepsin, and can be administered orally. It can lower blood pressure in monkeys with high renin status. Therefore, the amino acid derivatives represented by the general formula () and their pharmacologically acceptable acid addition salts of the present invention are useful as orally administrable antihypertensive agents.

Claims (1)

[Claims] 1. General formula (In the formula, R ¹ is a carbamoyl group or a lower alkoxycarbonyl group, His is an L-histidyl group, n is 0 or 1, and Y is -0-
or -NH-, and ^R2 is a linear or branched alkyl group having 1 to 7 carbon atoms) and pharmacologically acceptable acid addition salts thereof. 2 General formula (*C in the formula indicates S configuration, R ¹ , His, n, Y
and ^R2 have the same meanings as defined above) and their pharmacologically acceptable acid addition salts. 3 General formula (In the formula, R ¹ , His, *C, Y and R ² have the same meanings as above.) Amino acid derivatives according to claim 2 and their pharmacologically acceptable acid additions salt. 4 General formula (In the formula, R ¹ , His, *C, Y and R ² have the same meanings as above.) Amino acid derivatives according to claim 2 and their pharmacologically acceptable acid additions salt. 5 formula The amino acid derivative according to claim 3, represented by the formula (His and *C have the same meanings as above) and a pharmacologically acceptable acid addition salt thereof. 6 formula The amino acid derivative according to claim 3, represented by the formula (His and *C have the same meanings as above) and a pharmacologically acceptable acid addition salt thereof. 7 formula The amino acid derivative according to claim 3, represented by the formula (His and *C have the same meanings as above) and a pharmacologically acceptable acid addition salt thereof. 8 formula The amino acid derivative according to claim 3, represented by the formula (His and *C have the same meanings as above) and a pharmacologically acceptable acid addition salt thereof. 9 formula The amino acid derivative according to claim 4, represented by the formula (His and *C in the formula have the same meanings as above) and a pharmacologically acceptable acid addition salt thereof.