SYNTHESIS AND OPIATE ACTIVITY OF HUMAN β‐ENDORPHIN ANALOGS WITH VARIOUS CHAIN LENGTHS

Abstract
The synthesis of .beta.h[human]-endorphin [.beta.h-EP] -(1-15), -(1-21), -(1-26), -(1-28) and -(1-29) was accomplished by the solid-phase method. The opiate activities of the peptides were measured in the guinea pig ileum assay. Their relative potencies were .beta.h-EP, 1.00; Met-enkephalin, 0.25; .beta.h-EP-(1-15), 0.17; .beta.h-EP-(1-21), 0.46; .beta.h-EP-(1-26), 0.48; .beta.h-EP-(1-28), 0.89, .beta.h-EP-(1-29), 1.04.