Peptides and therapeutic applications thereof

摘要

This invention relates to peptide derivatives of the formula: Tyr-A-Gly-B-C-D (I) in which: A is a D.Ala, AzaGly, Aib, D.Ser., D.Thr, D.Cys, homo Serine, beta Phe Ser, beta OH Leu, 4OH Ile, alpha , beta , gamma OHNor Val or OH Val residue in which the side-chain OH or SH groups, when same exist, may be free or protected (i) by a straight- or branched-chain alkyl containing 1-6 carbon atoms, (ii) by an unsubstituted phenyl radical or a phenyl radical substituted with one or more fluorine atoms, (iii) by an unsubstituted benzyl radical or a benzyl radical substituted with one or more fluorine atoms, (iv) by an aliphatic acyl radical having 1-6 carbon atoms or an acyl radical COX in which X is a phenyl, benzyl or benzhydryl radical, optionally substituted with one or more fluorine atoms, B is a L.Phe, pF.L.Phe or pentafluoro L.Phe residue, C is a Leu, N.Leu or Ile residue of D or L configuration, D is hydrogen or a group of the formula: in which n=0, 1 or 2, R is a hydrogen atom or a radical as defined for the protection of group OH of residue A, Y is a hydrogen atom, a group hydroxy, carboxy, carbamoyl, a group OR1, COOR1 or CONHR1 in which R1 represents a radical as defined for the protection of group OH of residue A, a phosphatidylethanolamine chain or a chain NH(CH2)nR3NR2R2+RF in which n is an integer from 0 to 3, R2 is a hydrogen atom or a straight alkyl radical containing 1-4 carbon atoms, and R3 is a hydrogen or oxygen atom or a straight alkyl residue containing 1-4 carbon atoms, and their pharmaceutically acceptable salts. Said compounds are therapeutically useful, typically an analgesic, psychotropic and anti-diarrheic agents.