Chemical constituents from Mylabris phalerata and their cytotoxic activity in vitro

Ten compounds were isolated from Mylabris phalerata by using preparative HPLC and column chromatography over MCI gel. On the basis of physical-chemical properties, NMR and MS data analysis, the compounds were identified as 5'-[(1 R,2 R,3 S,6R)-1-hydroxymethyl-2-methyl-3,6-epoxycyclohexane-1,2-dicarboximide]- ethyl-2'-methyl-2'-butenoate (1),cantharidin (2), cyclo-(L-Pro-L-Ala) (3), cyclo-(R-Pro-R-Leu) (4), cyclo-(S-Pro-R-Leu) (5), cyclo-(D-Pro-L-Tyr) (6), indole-3-aldehyde (7), 3-indoleacetic acid (8), valerolactam (9), and 4-hydroxyphthalid (10).Compound 1 was a new compound, and compounds 2-10 were obtained from this genus for the first time. Compounds 1-9 were subjected to cytotoxic activity on HCT-116, HepG2, BGC-823, NCI-H1650, A2780 cell lines, and only compound 2 showed inhibitory effect on all cancer cell lines.