Synthesis and structure-activity relationships of deltorphin analogues

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

1991-01-01

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Abstract

In order to study the structure-activity relationships of natural opioid deltorphins (H-Tyr-D-Met-Phe-His-Leu-Met-Asp-NH2 and H-Tyr-D-Ala-Phe-Asp [or Glu]-Val-Val-Gly-NH2), 15 analogues were synthesized by the solution method. Their activities were determined in binding studies based on displacement of mu- and delta-receptor selective radiolabels from rat brain membranes and in two bioassays, using guinea pig ileum and mouse vas deferens. The obtained data indicate that the high delta-selectivity of deltorphins can be due to the constitution/conformation of the C-terminal part and, at least in part, to preselection by charge.