Synthesis of cyclic and acyclic partial retro-inverso modified enkephalins.
The cyclic partial retro-inverso modified enkephalins, H-Tyr-cyclo[-D-Glu-Gly-gPhe-D-Leu-] (I), H-Tyr-cyclo[-D-A2bu-Gly-gPhe-R&S-mLeu-] (IIf, IIs), and H-Tyr-cyclo[-D-Glu-Gly-Phe-gLeu-] (III), have been synthesized by solution methodology. In a like manner, their corresponding acyclic analogs Ia-IIIa containing D-Ala2 have also been prepared. Gem-diaminoalkyl residues were generated by conversion of Boc-dipeptide carboxamide to the corresponding gem-diaminoalkyl "dipeptide" salt using [bis(trifluoroacetoxy)iodo] benzene. Cyclizations were achieved at high dilution utilizing diphenylphosphoryl azide as the coupling reagent.
D004745:Enkephalins / Q000138:chemical synthesis*; D010456:Peptides, Cyclic / Q000138:chemical synthesis*; D011487:Protein Conformation; D013329:Structure-Activity Relationship
D004745:Enkephalins; D010456:Peptides, Cyclic