THE SEMICARBAZONE PEPTIDOMIMETIC GROUP IN IMINO AZA PEPTIDES

The semicarbazone moiety (C-CH=N-NR-CO-NH-C), either obtained by coupl ing a peptide aldehyde with a semicarbazide, or by action of an alkyli socyanate on a peptide hydrazone, is a dipeptide isostere. The structu re of four imino aza dipeptides, analogues of the Pro-Gly, Pro-Ala and Pro-Phe dipeptides, has been studied in solution by H-1-NMR and IR sp ectroscopy, and in the solid state by X-ray diffraction.