Pharmaceutical peptides, preparation, use and intermediates

Abstract

Novel peptides of formula (I) ##STR1## wherein R.sup.1 is hydrogen, alkyl of 1 or 2 carbon atoms or an amidino group, R.sup.2 is alkyl of 1 or 2 carbon atoms, R.sup.3 is hydrogen or carbamyl, X.sup.2 is a D-radical having the structure: ##STR2## Z.sup.1 and Z.sup.2 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 R.sup.3 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.

Dependencies are inferred from the claim text.