One new cyclopeptide was isolated from the ethyl acetate fraction of the 75% EtOH extract of Selaginella tamariscina by various column chromatography methods(HP-20, polyamide and semi-preparative HPLC). Its structure was identified as selapeptin A(1) by extensive spectroscopic analysis(HR-ESI-MS, 1 D and 2 D NMR). Compound 1 was evaluated for cytotoxic activities by MTT assay. It showed potent cytotoxic activity against B16 F10 with the inhibition rate of 51.57%±4.34% at 40 μmol·L~(-1) while had no impacts on MDA-MB-231 and MDA-MB-468 at 100 μmol·L~(-1).
Keywords: Selaginella tamariscina; cyclopeptide; cytotoxicity; selapeptin A; structural identification.