JPH0714878B2 - Prolyl endopeptidase inhibitor containing pyrrolidine amide as an active ingredient - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to general formula (1) (In the formula, n represents 1, 2, 3 or 4, and R is a carbon number of 1 to 1.
Which represents an alkyl group having 8 carbon atoms, an arylalkyl group having 7 to 12 carbon atoms, or a methylthioalkyl group having 3 to 10 carbon atoms) as an active ingredient, and to a prolyl endopeptidase activity inhibitor.

More specifically, the present invention provides prolyl endopeptidase (EC, 3.4.21.26, Pro having the general formula (1).
The present invention relates to a prolyl endopeptidase activity inhibitor containing a compound exhibiting enzyme inhibitory activity against lyl-endopeptidase) as an active ingredient, and a drug, particularly the use as an antiamnestic agent.

(Prior Art) Prolyl endopeptidase acts on vasopressin, which is considered to be related to substance P, TRH (early line stimulating hormone) and neurotensin, which are considered to be neurotransmitters, and these Is known to inactivate. On the other hand, Dr. Tsuru and Dr. Yoshimoto of Nagasaki University found that compounds that inhibit prolyl endopeptidase activity prevent experimental amnesia caused by rat scopolamine, and reasoned that prolyl endopeptidase inhibitor is involved in memory consolidation. . As a result, it has been suggested that prolyl endopeptidase inhibitors could be used for the prevention and treatment of amnesia (Journal of Agricultural Chemistry, 58, 1147-1154 (1984)).

(Technical problem to be solved by the invention) Based on the above findings, the present inventor has a high safety as a natural compound in order to find a novel compound having strong prolyl endopeptidase inhibitory activity and sufficiently low toxicity. It was considered to synthesize a compound similar to a natural product by combining an amino acid and a peptide compound.

Based on the above idea, the inventors have found that the novel pyrrolidine amide derivative represented by the general formula (1) has anti-prolyl endopeptidase activity, and completed the present invention.
Many of the compounds of general formula (1) are new.

(Means for Solving the Problems) The pyrrolidine amide having the general formula (1) of the present invention is a well-known anti-amnestic agent of the piracetam derivative type in that it contains an amino acid and its pyrrolidine amide. Are very different, and because they are amino acid or peptide derivatives, their toxicity to the living body is extremely low.

Among the compounds of the general formula (1), the following compounds are preferable because of their high antiprolyl endopeptidase activity. In the following, these compounds may be referred to by the numbers in the cutlet.

The compound of the general formula (1) can be synthesized by a general peptide synthesis method, but is conveniently synthesized by the synthesis method described below. The abbreviations have the following meanings.

L-Pro: L-proline residue L-Val: L-valine residue L-Phe: L-phenylalanine residue L-Met: L-methionine residue L-nLeu: L-norleucine residue WSCD: N -Ethyl-N, N'-dimethylaminopropylcarbodiimide Z: benzyloxycarbonyl group The compound of the general formula (1) can be synthesized as follows.

First, general formula (2) (In the formula, n and R have the same meanings as described above.) The compounds in which the carboxylic acid terminal end is not amidated are represented by the general formula (3) (Wherein n represents the same meaning as described above, and X represents a halogen atom) and a general formula (4) (Wherein R represents the same meaning as described above) and is obtained by reacting the amino acid in the presence of a base. Examples of the base used in this reaction include alkali metal hydroxides, alkali metal carbon salts, trialkylamines and aromatic amines.

The reaction temperature is preferably room temperature or lower, and the solvent may be one that dissolves the above base.

The compound of general formula (1) is obtained by condensing this compound (2) with pyrrolidine using a condensing agent.

Examples of the condensing agent include reagents commonly used in peptide synthesis, such as N, N′-dicyclohexylcarbodiimide, WSCD, etc., but other methods such as the acid chloride method, mixed acid anhydride method, active ester method, etc. A commonly used method may be used.

Alternatively, the general formula (5) (Wherein R represents the same meaning as described above) and the above-mentioned general formula (3)
The compound of the general formula (1) can also be obtained by reacting the haloformate derivative represented by the formula (1) in the presence of a base in the same manner as described above.

When the prolyl endopeptidase activity inhibitor of the present invention is used for amelioration / treatment of amnesia, the active compound of the general formula (1) is mixed with a pharmaceutically acceptable adjuvant to give a pharmaceutical composition.

That is, the active ingredient is administered orally in solid dosage forms such as capsules, tablets, and powders, or in liquid dosage forms such as elixirs, syrups, and suspensions.
It is also used parenterally, for example as an injection and a suppository.

Examples of the solid dosage auxiliary agent contained in the pharmaceutical composition include solid powder carriers, lactose, saccharose, dextrose, mannitol, sorbit, cellulose, and the like.
Examples include glycine. Further, the pharmaceutical composition may contain silicon dioxide, talc, magnesium stearate, polyethylene glycol as a lubricant; starch, gelatin, tragacanth, methylcellulose, sodium carboxymethylcellulose, polyvinylpyrrolidone and the like as a binder. Further, examples of the disintegrant include starch and agar.

The pharmaceutical composition of the present invention is orally administered to an adult at a dose of 100 to 1000 mg as an active ingredient per day, or parenterally at a dose of 50 to 500 mg. It is obvious that the dose varies depending on the type of disease to be administered, age, weight of patient, degree of symptom, administration form, and may be different in the above range.

Since the active ingredient of the present invention was shown to have no toxicity even at 500 mg / kg / mouse from the results of the acute toxicity test of the compounds produced in Examples described later, the safety is sufficiently wide.

The present invention is further described in detail by the following examples.

Example 1 Z- _L Val-pyrrolidine amide (SUAM1240) L-valine (10 mmol) in 1N sodium hydroxide solution 2
It was dissolved in 0 ml and diluted with water to 30 ml. While stirring this aqueous solution under ice-cooling, a solution of Z-chloride (10 mmol) previously dissolved in 10 ml of benzene was slowly added dropwise. Immediately thereafter, 10 ml of 1N sodium hydroxide solution was added. After returning to room temperature, the mixture was stirred overnight.

After completion of the reaction, the mixture was extracted twice with ethyl ether to remove unreacted acid chloride. The water tank was acidified with hydrochloric acid, and the precipitated compound was extracted three times with ethyl acetate, and the solvent was distilled off under reduced pressure to obtain ZL-valine. Next this Z
-L-valine (1 equivalent) and pyrrolidine (1 equivalent) were dissolved in dry methylene chloride (about 100 ml), 1 equivalent of WSCD was added, and the mixture was stirred overnight. After completion of the reaction, the mixture was washed with 1N hydrochloric acid, saturated saline solution, saturated sodium hydrogen carbonate solution and saturated saline solution in this order, and dried over anhydrous magnesium sulfate. After concentration under reduced pressure, the residue was subjected to silica gel column chromatography to obtain the title compound.

Property: colorless substance IR spectrum (film, cm ^-1 ): 3270,2970,2870,1710,1630,1520,1445,1230,1020,750,7
00 NMR spectrum (CDCl ₃ , δ): 0.94 (3H, d, J = 11), 0.98 (3H.d, J = 11), 1.80 to 2.10
(5H, m), 3.50 to 3.80 (4H, m), 4.30 (1H, dd.J ＝ 6, J ＝
7), 5.08 (2H, dd, J = 12, J = 12) 5.52 (1H, d, J = 9),
7.34 (5H, s) Example 2 ZL-phenylalanylpyrrolidine amide (SUAM 124
1) By substituting L-phenylalanine for L-valine of Example 1, the title compound was obtained.

Property: colorless oil IR spectrum (film, cm ^-1 ): 3250,3030,2975,2880,1710,1630,1520,1495,1450,1340,
1280,1245,1060,1030,750,700 NMR spectrum (CDCl ₃ , δ): 1.50 ~ 1.80 (4H, m), 2.58 (1H, m) 3.00 (2H, m), 3.20 ~
3.50 (3H, m) 4.44 (1H, m), 5.08 (2H, dd, J ＝ 12, J = 1
2), 5.69 (1H, d, J = 9), 7.23 (5H, s), 7.36 (5H, s) Example 3 Z-L-methionine pyrrolidine amide (SUAM1242) Instead of L-valine of Example 1. The title compound was obtained by using L-methionine.

Property: Amorphous crystal IR spectrum (KBr, cm ^-1 ): 3250,3050,2975,2950,2920,2875,1720,1635,1535,1440,
1340,1260,1140,1060,740,700 NMR spectrum (CDCl ₃ , δ): 1.70 to 2.20 (6H, m), 2.80 (3H, s), 2.50 (2H, t, J =
7), 3.30 to 3.70 (4H, m) 4.62 (1H, m), 5.80 (2H, s),
5.68 (1H, d, J = 9), 7.32 (5H, s) Example 4 Z-L-norleucine pyrrolidine amide (SUAM1257) By substituting L-norleucine for the L-valine of Example 1 the title compound Got

Property: colorless oil IR spectrum (film, cm ^-1 ): 3280,2950,2870,1710,1630,1520,1450,1250,1020,750,7
00 NMR spectrum (CDCl ₃ , δ): 0.88 (3H, m), 1.36 (4H, m), 1.65 (2H, m), 1.90 (4H, m)
m), 4.44 (4H, m) 5.48 (1H, m), 6.08 (2H, s), 6.58 (1
H, d, J = 9), 7.35 (5H, s) Measurement of anti-prolyl endopeptidase activity The measurement of anti-prolyl endopeptidase activity was performed by Yoshimoto (T.
Yoshimoto and D. Tsuru, Agr. Biol. Chem. 42, 2417, 197
8) and so on. That is, 0.0025M Z-glycyl-
A mixture containing 0.25 ml of proline-β-naphthylamide, 0.99 ml of 0.1 M phosphate buffer (pH 7.0) and 0.01 ml of a solution of an anti-prolyl endopeptidase compound was placed in a test tube at 37 ° C.
After heating for 3 minutes, 0.1 ml of prolyl endopeptidase solution (0.2 unit / ml) was added and reacted at 35 ° C for 10 minutes. Then Triton X-1 in 1M acetate buffer (pH 4.0)
2.0 ml of 00 (TritonX-100) solution was added so that the final concentration of the surfactant would be 10%, and the mixture was left at room temperature for 15 minutes, and then the absorbance (a) at 410 nm was measured.

At the same time, a blind absorbance (b) was measured using only a buffer solution instead of the solution of the anti-prolyl endopeptidase compound,
The prolyl endopeptidase inhibition rate was calculated by the following formula: [(ba) / b] × 100, and the amount required for 50% inhibition [IC ₅₀ ] was determined.
The test results are shown in Table 1.

 ─────────────────────────────────────────────────── ─── Continued Front Page (1) 1-1 Wakayamadai, Shimamoto-cho, Mishima-gun, Osaka Prefecture 1-1-1 Wakayamadai, Suntory Ltd. (72) Inventor Ryuji Tanaka Wakayama, Shimamoto-cho, Mishima-gun, Osaka Prefecture 1-1-1 1-1, Suntory Ltd., Applied Microbiology Laboratory (56) References J. Chem. Soc. , Perkin Trans. 1 (9), (1975), P. 830-841

Claims (5)

[Claims] 1. A general formula: (In the formula, n represents 1, 2, 3 or 4, and R is a carbon number of 1 to 8
Which represents an alkyl group, an arylalkyl group having 7 to 12 carbon atoms, or a methylthioalkyl group having 3 to 10 carbon atoms) as an active ingredient, a prolyl endopeptidase activity inhibitor. 2. R is a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, an isopentyl group, a pentyl group, a hexyl group, an isohexyl group, a neohexyl group, a heptyl group or an octyl group. The prolyl endopeptidase activity inhibitor according to claim 1, which is 3. R is benzyl group, phenethyl group, phenylpropyl group, phenylbutyl group, phenylpentyl group,
The prolyl endopeptidase activity inhibitor according to claim 1, which is a toluylmethyl group or a toluylethyl group. 4. R is a methylthioethyl group, a methylthiopropyl group, a methylthiobutyl group, a methylthiopentyl group,
The prolyl endopeptidase activity inhibitor according to claim 1, which is a methylthiohexyl group, a methylthioheptyl group, a methylthiooctyl group or a methylthiononyl group. 5. The prolyl endopeptidase activity inhibitor according to any one of claims 1 to 4, which is used for treating amnesia.