Synthesis and properties of beta h-endorphin analogs containing the dynorphin-(1-13) sequence

Two analogs of beta h-endorphin containing dynorphin-(5-13) or dynorphin-(6-13) sequence have been synthesized by the solid-phase method. Biological activities of the analogs have also been investigated. It was found that the opiate activity is about three times more than beta h-endorphin in the guinea pig ileum assay. Both analgesic potency and opiate receptor-binding activity of the analogs are lower when compared with beta h-endorphin. However, the analogs have interesting behavioral effects in mice.