Synthesis, enzymic degradation, lipophilic properties, and biological activity of [D-alanine2, t-butylglycine 5]enkephalin amide

Article abstract of DOI:10.1002/hlca.19800630410

L-C(a)-t-Butylglycine (Bug), its amide, methyl ester, and N(a)-t-butoxycarbonyl derivative were prepared by an asymmetric synthesis, and the Hansch side-chain hydrophobic (lipophilicity) parameter determined. A new enkephalin analogue, H . Tyr-D-Ala-Gly-Phe-Bug . HN₂ was synthesized which is pharmacologically active in two in vitro assays and strongly resistant against a number of enzymes in vitro.