Synthesis, characterization and biological evaluation of a glycine-rich peptide - Cherimolacyclopeptide E

Abstract

The synthesis of a natural cyclic peptide cherimolacyclopeptide E (12) by coupling oftripeptide units Boc-gly-leu-gly-OCH3 (9) and BoC-ßhe-tyr-pro-OCH3 (10) after proper deprotection at carboxyl and amino terminals followed by cyclization of linear hexapeptide segment, is described. Structure elucidation of the cyclopeptide 12 is based on detailed spectral analysis such as FTIR, 1H NMR, 13C NMR, FAB MS and elemental analysis. After biological screening, the newly synthesized peptide exhibited high cytotoxicity against Dalton's lymphoma ascites (DLA) and Ehrlich's ascites carcinoma (EAC) cell lines with CTC50 values of 2.16 and 4.96 uM, and potent antimicrobial activity against pathogenic microbes P. aeruginosa, E.coli and C. albicans with MICs between 12.5-6 μg/mL. Furthermore, compound 12 possessed moderate anthelmintic activity against earthworms M. konkanensis, P. corethruses and Eudrilus sp. at 2 mg/mL dose level. © 2007 Sociedad Chilena de Química.