PARASUBSTITUTED PHENYLALANINE-4 ANALOGS OF [L-ALA(3)]DPDPE - HIGHLY SELECTIVE DELTA-OPIOID RECEPTOR LIGANDS

Several para-substituted Phe(4) analogues of the delta(1)-selective an tagonist [L-Ala(3)]DPDPE (DPADPE) were prepared and evaluated for thei r brain-binding and in vitro pharmacological effects. Unlike the p-hal oPhe(4) analogues of DPDPE and the deltorphins, similar analogues of D PADPE with electron-withdrawing groups substituted at the para-positio n of the Phe(4) aromatic ring did not all have increased potency and s electivity for delta opioid receptors, but all retained high potency a nd selectivity for delta opioid receptors greater than DPDPE. (C) Munk sgaard 1997.