Opioid agonists and antagonists - Peptides containing N-terminal allyl groups and or a thiomethylene linkage in place of a peptide-bond

BALBONI, GIANFRANCO;SALVADORI S;MARASTONI M;TOMATIS R;BOREA PA;BIANCHI C.

1988-01-01

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Abstract

Peptides containing N-allyl or N,N-diallyl groups at the N-terminus have been synthesized as potential opioid antagonists. A number of analogues with an amide bond replaced by a thiomethylene group have also been prepared. In brain binding assays and in guinea-pig ileum and mouse vas deferens preparations, the analogues generally displayed low affinity for µ- and δ-receptors as well as agonist activities in in vitro tests. N,N-Diallyl-Phe-D-Ala-Phe-Gly-NH2(28) was found to be a moderately potent but highly selective antagonist at δ opiate receptors.