Synthetic and Cytotoxic and Antimicrobial Activity Studies on Annomuricatin B

The first total synthesis of annomuricatin B (8) is described via coupling of the tripeptide Boc-L-asparaginyl(benzhydryl)-L-alanyl-L-tryptophan-OH and the tetrapeptide L-leucyl-glycyl-L-thryl-L-proline-OMe followed by cyclization of the linear heptapeptide fragment. On pharmacological investigation, it was observed that the cycloheptapeptide 8 displays moderate cytotoxicity against Dalton's lymphoma ascites and Ehrlich's ascites carcinoma cell lines with cytotoxic inhibitory concentration (50 %) values of 11.6 and 14.1 mu M, in addition to potent antidermatophyte activity against Trichophyton mentagrophytes and Microsporian audouinii with a minimum inhibitory concentration of 6 mu g mL(-1). Moreover, Grain-negative bacteria and Candida albicans were found to be moderately sensitive towards the newly synthesized peptide.