Pharmacologically active tripeptides and process for their synthesis

Pharmacologically active tripeptides, with at east a retro-inverted peptidic bond, definable by means of the following general formulae:their pharmaceutically acceptable salts, esters or alkyl amides, whereinR, represents a hydrogen atom, an alkyl group with a maximum of 7 carbon atoms, an aryl, hydroxyai- kyl or hydroxyarylalkyl, guanidylalkyl, amino-alkyl, alkyl oxy-alkyl, acylamino-alkyl, imidazolylalkyl, indolyl-alkyl, mercapto alkyl, alkylmercaptoalkyl, carbamoylalkyl, carboxyalkyl, alkyl-carbamoylalkyl or alkyloxy-carbonylalkyl group;R2 represents agroup,Z is an OH, OR3, NH2, NHR3, group whereinR3 represents an alkyl group with a number of carbon atoms comprised within the range of from 1 to 10.