FR2600067A1 - Pseudopeptides which inhibit gastric secretion - Google Patents

Abstract

The invention relates to pseudopeptides which inhibit gastric secretion. These compounds are of the formula: in which: X represents hydrogen, an acetylamino group, a tert-butyloxycarbonylamino group or a benzyloxycarbonylamino group; R1 represents an n-butyl, isobutyl, methylthioethyl or ethylthioethyl group; A and B are necessarily different and represent either an -NH- group or a -C=O group; R2 represents a group: in which R3 denotes a group chosen from: as well as their salts with inorganic or organic bases.h

Description

 Gastrin is a polypeptide hormone that has multiple biological activities, the main one being the stimulation of gastric secretion.

 It has been established that many synthetic peptides derived in particular from the C-terminal tetrapeptide of gastrin retain all or part of the biological activities of gastrin.

 It is also known that the replacement of certain amino acids in the sequence of gastrin or its fragments leads to peptide derivatives which sometimes antagonize at a high level the action of gastrin on gastric secretion.

 However, the therapeutic use of such derivatives is considerably limited by the brevity of their activity due to the very rapid destruction of peptide compounds in the body.

 The subject of the present invention is novel pseudopeptide derivatives which possess a strong gastric secretion antagonistic activity associated with a prolonged duration of action in vivo.

dans laquelle - X représente l'hydrogène, un groupe acétylamino, un groupe
tertiobutyloxycarbonylamino ou un groupe benzyloxycarbonylamino ; - R1 représente un groupe n-butyie isobutyle méthylthioéthyle ou éthplthioéthyé; - A et B sont obligatoirement différents et représentent soit un
groupe -NH-, soit un groupe -C=O - R2 représente un groupe

dans lequel R3 désigne un groupe choisi parmi

The compounds according to the invention correspond to the general formula

in which - X represents hydrogen, an acetylamino group, a group
tert-butyloxycarbonylamino or benzyloxycarbonylamino group; R 1 represents a n-butyl isobutyl methylthioethyl or ethylthioethyl group; - A and B are necessarily different and represent either a
group -NH-, that is a group -C = O - R2 represents a group

wherein R3 denotes a group selected from

 The salts which the compounds of formula (I) can form with the inorganic or organic bases form an integral part of the invention.

C-labeled atoms are asymmetric carbon atoms and therefore can exist as 2 D and L isomers. All isomers are included in the present invention.

 However, the preferred compounds have the L configuration on carbon atoms (1) and (2).

 The present invention also comprises a process for preparing the pseudopeptides according to the invention; wherein the deprotection steps are performed according to methods well known to those skilled in the art.

dans lequel Y et Y1 sont des groupes protecteurs, qui,traité en solution à température ambiante par le bis((trifluoroacétoxy) iodo) benzène conduit au dérivé gem diamine

isolé sous forme de trifluoracétate et en conservant la stéréochimie des 2 carbones asymétriques.For the compounds (I) where A represents NH and B represents CO, starting from the protected dipeptide amide

wherein Y and Y1 are protecting groups, which, treated in solution at room temperature by bis ((trifluoroacetoxy) iodo) benzene leads to the gem diamine derivative

isolated in the form of trifluoroacetate and maintaining the stereochemistry of the two asymmetric carbons.

The amino derivative (b) is condensed in solution with an activated ester of tryptophan protected on the amine or with an activated ester of 3-indolylpropionic acid to yield compound (c)

 By hydrogenation in solution in the presence of palladium on charcoal as a catalyst, both the protective group of the terminal amine and the protecting group Y of the side chain are removed.

 On the derivative (d) thus obtained, the acid R 2 COOH is then condensed using either the acid itself in the presence of a condensing agent such as a carbodiimide or an activated derivative of the acid, by for example, its ester with N-hydroxy succinimide or else the acid chloride R, COCl to give compound (I).

 When R 3 is NH and when it is accessible, it is also possible to replace the acid R2 COOH or its activated ester with an isocyanate R2-NCO which leads by addition to the corresponding compound (I).

According to a variant of the method, the order of the steps of the synthesis can be reversed. From the protected dipeptide amide (a), it is possible, after deprotection on nitrogen, to condense the acid R2 COOH or one of its derivatives as indicated previously to form the compound (e)

isolé sos forme de trifluoracétate.The latter treated as indicated above with (bis (trifluoroacetoxy) iodo) benzene leads to the gem diamine derivative (f)

isolated sos form of trifluoroacetate.

Condensing (f) with an activated ester of tryptophan or 3-indolpropionic acid gives the protected compound (g)

 Finally, by catalytic hydrogenation, the protecting group of the side chain which provides the corresponding compound (I) is removed.

qui par action de bis (trifluoracétoxy) iodo benzène, comme indiqué ci-dessus, conduit au dérivé aminé :

isolé sous forme de trifluoracétate et dont la configuration des carbones asymétriques est conservée.In the case of the compounds (I) in which A represents -C = O and B represents NH, the protected dipeptide amide is used.

which by action of bis (trifluoroacetoxy) iodo benzene, as indicated above, leads to the amino derivative:

isolated as trifluoroacetate and whose configuration of asymmetric carbons is conserved.

Derivative (i) is then condensed with R2COOH acid or with an activated derivative thereof to yield compound (j)

After deprotection of the latter with trifluoroacetic acid, an activated N-protected tryptophan ester or an activated ester of indolyl-3-prioponic acid is condensed on the amine thus liberated to yield compound (k).

 Catalytic hydrogenation in the presence of palladium on charcoal eliminates the protective group of the side chain to obtain the corresponding compound (I).

 the starting materials of formula (a) or (h) are known products or can be prepared by the usual methods of peptide synthesis.

 The following nonlimiting examples illustrate the invention.

In these examples, the following abbreviations will also be used:
Trp: Tryptophan.

Asp: As acetic acid.

Leu: Leucine.

Asp (OBzl): Aspartic acid protected as benzyl ester of
the acid function of the side chain.

 OSu: Ester of N-hydroxysuccinimide.

DMF: dimethylformamide.

TFA: Trifluoroacetic acid.

HOBt: Hydroxy-1 benzotriazole.

DCC: N, N'-dicyclohexylcarbodiimide.

DCU: N, N'-dicyclohexylurea.

DIEA: Diisopropylethylamine.

Nle: Norleurine
Z: benzyloxycarbonyl
Boc: tertiobutyloxycarbonyl
Bzl: benzyl.

EXAMPLE 1

A) ZD-Asp (OBzl) -D-Leu- * NH2
To a solution cooled to 150 ° C. with 2 g of ZD-Asp (OBzl) -OH in 10 ml of DMF, 0.63 ml of N-methylmorpholine and 0.76 ml of isobutyl chloroformate are added.

 After stirring for 5 minutes at 150 ° C., 0.79 g of dleucinamide is added and the reaction mixture is then stirred for 1 hour at 0 ° C. and then for 1 hour at room temperature. By vigorous addition of 150 ml of aqueous 10% citric acid solution, a colorless precipitate is formed. It is filtered off and washed successively with water (3 times 80 ml), with saturated sodium bicarbonate solution (3 times 80 ml) and then again with water until neutral. After drying under vacuum in the presence of phosphorus pentoxide, 2.47 g of the expected product are obtained.

F: 158-1600C;
(a) 20D + 13.5 (c = 1.04 DMF);
Yield: 94 m.

 To a suspension of 2.2 g of the dipeptide amide obtained above in 20 ml of the acetonitrile-water mixture (50-50 vol / vol) was added 2.12 g of (bis (trifluoroacetoxy) iodo) benzene. After stirring for 3 hours at ordinary temperature, a clear solution containing no starting material is obtained. The solvents are evaporated under reduced pressure and a colorless solid residue is obtained which is dried under vacuum over phosphorus pentoxide.

This product is used as is for the next step.

 The dry residue from the previous step is dissolved in 5 ml of DNF containing 0.80 ml of DIEA and 1.6 g of Boc-L-Trp-OSu. The mixture is stirred for 2 hours at room temperature then the expected compound is isolated as indicated in paragraph 1.

Weight: 2.79 g
Yield: 96%;
Mp 185 C, decomposition.

 a) Deprotection.

 2 g of the compound obtained above are dissolved in 30 ml of DMF and 10% palladium on charcoal catalyst is added. It is hydrogenated for 4 hours at room temperature and atmospheric pressure. The catalyst is filtered off and the solvent is removed under vacuum at a temperature below 400C.

 Trituration of the residue in ethyl ether gives a colorless solid (1.08 g) used as it is for the next step.

 b) Coupling.

 To the solution of 0.667 g of N-hydroxysuccinimide ester of DL benzyl-2-malonic monoamide acid in 5 ml of DMF is added the protected compound prepared above and 0.37 ml of DIEA. It is stirred for 4 hours at room temperature and then 100 ml of a 10% aqueous solution of citric acid is added. A colorless precipitate is obtained which is filtered off and washed with water (3 x 50 ml), ethyl acetate (3 x 50 ml) and ethyl ether (3 x 50 ml). After drying under vacuum over phosphorus pentoxide, 1.05 g of the expected product is obtained.

Mp 2100 ° C decomposition
D + 7.0 (c = 1.4 DMF)
Yield: 52 tO.

EXAMPLE 2

From the protected dipeptide Boc-L-Leu-L-Asp (OBzl) - NE2 (2.5 g) the corresponding diamine compound is prepared by the action of 2.6 g of (bis (trifluoroacetoxy) iodo) benzene. according to the method described in Example 1-B.

 To the solution in 15 ml of DMF of the trifluoroacetate thus obtained, 0.99 ml of DIEA, 1.11 g of D, L-benzyl-2-malonic monoamide acid and 0.78 g HOBt were added. The mixture is cooled to OOC and 1.1 g of N- (3-dimethylaminopropyl) N-ethyl carbodiimide hydrochloride are added. Stirred 16 hours at room temperature. By addition of 100 ml of a 10% aqueous solution of citric acid, a colorless solid is separated off, which is filtered off and washed with water (3 × 80 ml) and acetone (10 ml). ) and ethyl ether (3 times 80 ml).

 After drying under vacuum in the presence of phosphoric anhydride, 2.15 g of the expected product is obtained.

F: 184-1870C;
(A) 20D-3.0 (c = 1.3 DMF)
Yield: 65%.

 The 1-g terminal nitrogen of the compound obtained above is deprotected by treatment with 3 ml of acid-trifluoroacetic acid at room temperature for 30 minutes. 100 ml of ethyl ether are added under vigorous stirring and a colorless precipitate is obtained which is filtered off, washed several times with ethyl ether and dried under vacuum over potassium hydroxide.

 The trifluoroacetate thus obtained is dissolved in 3 ml of DMF and 0.3 g of DIEA and 0.642 g of Boc-L-Trp-OSu are added. It is stirred for 2 hours at room temperature and isolates the expected product as indicated in Example 1, paragraph A.

Weight: 1.20 g
F: 200-205 ° C;
20
(α) 20D-9.9 (c = 1.03 DMF)
Yield 98%.

 The benzyl ester of the side chain is removed by catalytic hydrogenation in the presence of palladium on charcoal of 1 g of the product obtained previously in solution in 80 ml of an ethanol-DYF mixture (50-50, vol / vol). The product is isolated as indicated in Example 1, paragraph D.

0.84 g of the expected product is obtained;
F: 225 C with decomposition
(a) 20D-14.4 (c = 1.05, D! S)
Yield: 95 0.

EXAMPLE 3

A) Boc-D-Asp (OBzl) -DNl-NlI2
Prepared according to Example 1, paragraph A, replacing Dleucinamide with the same amount of D-norleucinamide.

 In the same way we obtain a colorless solid.

F: 140-1450C 20
(a) D + 1834 (c = 0> 98 DMP)
Yield 95.0.

 3) N-hydroxysuccinimide ester of 3-phenylpropionic acid.

 To the cooled OOC solution of 5 g of 3-phenylpropionic acid and 5.75 g of N-hydroxy succinimide in 40 ml of dimethoxy-1> 2 ethane, 6.87 g of DCC are added.

Stirring at room temperature for 16 hours and then filtering the
DCU formed. The filtrate is diluted with 200 ml of ethyl acetate and the solution is washed with a cold aqueous solution of 2.0 ml of sodium bicarbonate (3 × 80 ml), with water (50 ml), with stirring. 1N aqueous solution of potassium bisulfate (100 ml) and finally with saline (100 ml). The solution is dried over magnesium sulfate and the solvents evaporated in vacuo. A colorless solid is obtained which is recrystallized from an ethyl acetate-hexane mixture.

Weight: 5.69g
F: 112-150C
Yield: 69, Ó.

C) C6H5CH2CH2CO-D-Asp (OBz1) -DNl-NH2
Nitrogen is deprotected, 1145 g of the compound prepared in
A above by the action of trifluoroacetic acid at room temperature for 30 minutes.

 The trifluoroacetate thus obtained is dissolved in 1 ml of DMF. 0.574 ml of DIEA and 0.816 g of 3-phenylpropionic acid N-hydroxysuccinimide ester are then added. Stirred 2 hours at room temperature and then isolates the product as indicated in Example 1 paragraph A.

F: 174-1770C.

 1.3 g of the compound prepared above is treated with 1.26 g of (bis (trifluoroacetoxy) iodo) benzene according to the technique of Example 1, paragraph B. In the same way, the trifluoroacetate is isolated from the gem diamino derivative. dissolved in 5 ml of DMF. 0.48 ml of DIEA and 0.883 g of Boc-L-Trp-OSu are added. The mixture is stirred for 16 hours at ambient temperature and then the product is isolated according to the technique of Example 1-A.

F: 173-1780C
(a) D 5.6 (c = 1, DMP)
Weight: 1.52 g
Yield: 95.0.

 The side chain of the above compound is deprotected by catalytic hydrogenation as indicated in the previous examples.

 From 1.43 g of the protected derivative, 0.95 g of the expected compound is obtained.

F: 1900C (decomposition)
20
(a) D + 9.8 (c = 1.1, DXMF);
Yield 80%.

EXAMPLE 4

A) G6 X; CH2NHCO-D-Asp (OBzl) -ND-N'X2
1.65 g of the compound of Example 3, paragraph A is deprotected on nitrogen by the action of trifluoroacetic acid for 30 minutes at room temperature.

 The trifluoroacetate thus obtained is dissolved in 25 moles of ethyl acetate and 0.651 g of DIEA and 0.47 ml of benzyl isocyanate are added. A precipitate is rapidly formed, filtered off, washed with ethyl acetate (3 x 43 ml), ethyl ether (3 x 40 ml) and dried under vacuum.

Clear crystals - Weight: 1.6 g
F: 208-220C
(a) 20D + 1.9 (c = 1.2D> F)
D
Yield: 92.0.

 This product is prepared from the preceding compound as indicated in Example 3> paragraph D.

F: 2100C (decomposition);
(a) 20
D - 233 (c = 1.09> DMP)
Yield: 69.0.

 The side chain of the preceding product is deprotected as in Example 3, paragraph E.

F: 200 C (decomposition
20 - 5.3 (c = 1, DMF).

D
EXAMPLE 5

 This compound is prepared from the trifluoroacetate of the gem diamined derivative described in Example 2-A by condensation with the N-hydroxysuccinimide ester of 3-phenylpropionic acid (Example.3, paragraph B) according to the technique described in US Pat. Example 3-C.

 After chromatography on a silica column, eluting with ethyl acetate / hexane, the expected product is obtained in the form of a colorless solid.

F: 155-1580C
(a) D ~ 8.7 (c = 1, DET);
Yield: 65.

 The procedure is as in Example 2-B from the compound obtained above.

Mp 175-1850 ° C; 20
(a) D - 14.8 (c = 1, DMF)
Yield: 92.0.

 The product obtained above is deprotected by operating as in Example 2-C. Colorless solid.

F: 2050C (decomposition)
(a) 20D-1318 (c = 1.3, DMF)
Yield 87%.

EXAMPLE 6

 The procedure is as in Example 5, replacing in the first step the coupling with the activated ester of 3-phenylpropionic acid by the reaction of the gem diamino derivative with benzyl isocyanate according to the technique of Example 4 -AT.

Is thus isolated successively

Mp 175-1780 ° C; (A) 2 D ~ 10.1 (c = 1, DMF);
Yield: 51.0.

F: 2000C (decomposition) (a) 20
D - 15.7 (c = 1.1> DMP)
Yield: 77% and the title compound
F: 1500C (decomposition)
20
(a) D - 17.4 (c = 1.2, DMF)
Yield: -80%.

 The compounds according to the invention have been studied with regard to their therapeutic properties. In particular, these compounds have been studied in vivo with regard to their gastric secretory effect.

 For this study, the derivatives (I) were dissolved in 0.1 N ammonia and the Millipore filtered solution (0.2 μm) lyophilized.

 The model chosen for measuring the secretory effect is that of the reperfused anesthetized rat stomach. The protocol followed is a modification of that previously described by GHOSH and SCHILD.

 A 300 g male Wistar strain, fasted for 18 hours, is anesthetized with urethane (10, 1.5 ml / 100 g i.p. solution). Tracheotomy and catheterization of the penile vein are then performed, which will allow the i.v. administration of the peptides. A cannula is then placed in the esophagus to the cardia and a second in the duodenum (by a duodenotomy performed about 3 cm from the pylorus) into the gastric antral zone.

 A propionic-succinic solute (pH 5.5) which gives a linear variation of the pH as a function of the H + ion concentration is used to infuse the stomach with a flow rate of 3 ml / min. The body temperature, as well as that of the solute, is controlled and maintained at 30 ° C. The acid secretion of the stomach will cause a pH variation detected by the glass electrode and recorded as a function of time. After stabilization of basal secretion, intravenous gastrin is injected either as an infusion or as a single injection. The response is recorded as a function of time and the amount of secreted acid is measured on the recording by difference with basal secretion.

 The same experiment is carried out by combining the product to be studied with the stimulant in variable concentration ratios.

 The amount of H + ions. secreted in the presence of the product to be studied is compared with the amount of H + ions. secreted after administration of gastrin alone and the result is expressed as inhibition. By using different doses of the product to be studied, it is possible, from the results obtained, to determine the effective dose (ED 50) or dose which inhibits by 50% the secretion of H + ions.

caused by gastrin.

 Finally, the peptide is administered alone at different doses to determine its possible agonist effect on gastric secretion.

The results obtained with various products of the invention are summarized in the following table.

<Tb>

: <SEP> Product <SEP> of <SEP>: <SEP> Effect <SEP> agonist <SEP>: <SEP> Effect <SEP> antagonist
<tb> Example <SEP> (1) <SEP>: <SEP> DE <SEP> 50 <SEP> mg / kg
<tb>: <SEP> 1 <SEP>: <SEP> Low <SEP>: <SEP> 0,1
<tb>: <SEP> 1 <SEP>: <SEP> Low <SEP>: <SEP> 0.1 <SEP>:
<tb>: <SEP> 2 <SEP>: <SEP> Low <SEP>: <SEP> 0.2
<tb>: <SEP> 3 <SEP>: <SEP> Low <SEP> 1.5 <SEP>
<tb>: <SEP> 4 <SEP>: <SEP> Low <SEP>: <SEP> 0.7
<tb>: <SEP> 5 <SEP>: <SEP> Null <SEP>: <SEP> 0,1
<tb>: <SEP> 6 <SEP>: <SEP> Null <SEP>: <SEP> 0.6 <SEP>:
<tb><SEP> 6 <SEP>: <SEP> Null <SEP>: <SEP> 0i6 <SEP>
<tb> (1) Low agonist effect means that the agonist effect
is only measurable from 3 mg / kg.

Zero agonist effect means no activity
agonist has been detected up to 3 mg / kg.

These results show that the compounds according to the invention exhibit an agonist effect which
or no vis-à-vis the gastrin - the compounds according to the invention exhibit an inhibitory effect
potent gastric secretion.

 In addition, the compounds tested have a long duration of action. Thus the compound of Example 5 in single injection inhibits gastric secretion for more than 2 hours.

 Consequently, the compounds according to the invention can be used in human therapy in all cases where it is useful to reduce gastric secretion and in particular for the treatment of peptic ulcers.

 The compounds of the present invention may be preferably used by injection: intravenously, intramuscularly or subcutaneously. They are used in a solvent such as saline (isotonic saline).

 The dosage may vary according to the intensity of the desired therapeutic effect, the severity of the condition to be treated and the route of administration used. It must therefore be determined for each patient according to these various criteria. Most often it is between 0.1 and 10 mg of active ingredient per kg of body weight.

Claims (8)

1. New pseudopeptide derivatives of the general formula

 in which - X represents hydrogen, an acetylamino group, a group  tertiobutyloxycarbonylamino or a group  benzyloxycarbonylamino - R1 represents a group n-butyg isobutyla  methylthioethyl or ethylthioethyl; - A and B are necessarily different and represent either  a group -N-, that is a group -C = O-R2 represents a group

 wherein R3 denotes a group selected from -CH2-

 -O- and -NH besides their salts with mineral or organic bases. 2. Pseudopeptides according to claim 1, wherein X represents  hydrogen. 3. Pseudopeptides according to claim 1, wherein X represents a group  acetylamino, tert-butyloxycarbonylamino or  benzyloxycarbonylamino. 4. Pseudopeptides according to claim 3, characterized in that  that they correspond to the formula (I) in which the centers  of asymmetry (1) and (2) are configuration L. 5. Process for obtaining pseudopeptides of formula (I) where A  represents NH and B represents CO, characterized in that  the protected dipeptide is treated in solution

 where Y and Y1 represent protecting groups and R, is as defined above by (bis (trifluoroacetoxy) iodo) benzene to form the diamino derivative

 -condensate it with an activated ester of tryptophan N  protected or with an activated ester of indolyl-3 acid  propionic to form the  compound

 optionally, the compound (I) is converted into one of its salts. R2COOH or one of its corresponding corresponding derivatives to obtain the compound of formula (I)  after removal of the Y1 and Y protecting groups of the compound (3), the aminated derivative thus obtained is reacted with an acid 6. Process for the preparation of the compounds of formula (I) according to claim 5 characterized in that  selectively deprotecting the amine of the dipeptide (1);  on the aminated derivative thus obtained, the acid R2COOH or one of its reactive derivatives is condensed which leads to the compound:

 the compound (4) thus obtained in solution is treated with (bis  (trifluoroacetoxy) iodo) benzene to form the amino derivative:

 the amine derivative (5) is condensed with an N-protected activated ester  tryptophan or with an activated ester of 3-indol propionic acid  according to a known method in peptide chemistry to obtain the  compound (6)

 - The protective group Y is removed to obtain the compound (I) - optionally, the compound (I) is converted into a salt thereof. 7. Process for obtaining pseudopeptides of formula (I) where A  represents CO and B represents NH, characterized in that: - the protected dipeptide is treated in solution

 one of its reactive derivatives to form the compound  the compound (8) thus obtained is treated with the acid R2COOH or

 by (bis (trifuloroacetoxy) iodo) benzene to form the diamine compound  seis.  optionally, the compound (I) is converted into one of its  obtain the compound (I)  the protective group Y is eliminated for  leads to the compound (6)  with an activated ester of 3-indolpropionic acid which  compound (9) with an N-protected tryptophan activated ester or  - after selective deprotection on nitrogen, the 8. Pharmaceutical compositions containing, as an immediate ingredient,  tif, a peptide of formula (I) in combination with a vehicle  pharmaceutically acceptable.