Pharmaceutical peptides, preparation, use and intermediates.

摘要

Novel peptides of formula (I) (I) wherein R1 is hydrogen, alkyl of 1 or 2 carbon atoms or an amidino group, R2 is alkyl of 1 or 2 carbon atoms, R3 is hydrogen or carbamyl, X2 is a D-radical having the structure: Z1 and Z2 are the same or different and each is hydrogen, halo, nitro or trifluoromethyl and at least one is other than hydrogen, m is 2, 3 or 4 and n is 0, 1 or 2, provided that when R3 is carbamyl then n is always 1; and salts thereof. The compounds have a selectively peripheral analgesic effect when administered to mammals and also exhibit antidiarrhoeal and antitussive activity and may thus be used in human or veterinary medicine for the relief or prevention of pain, for the treatment of diarrhoea or dysentery and for the suppression of cough.