A new cytotoxic plumbagin derivative from roots of Diospyros undulata

A new plumbagin derivative, 3-(5-oxohexyl)plumbagin (1), together with six known benzoquinone derivatives (2-7), four known triterpenoids (8-11) and coniferyl aldehyde (12) were isolated from Diospyros undulata roots. Their structures were elucidated by intensive spectroscopy including 1 D and 2 D NMR, UV, IR and MS spectrometric analysis. Compound 1 exhibited strong cytotoxicity against three cancer cell lines as lung cancer (NCI-H187), breast cancer (MCF-7), and oral cancer (KB) with IC50 values of 7.16, 12.85 and 28.67 mu M, respectively. Moreover, it did not showed cytotoxicity to Vero cells. In addition, the antimicrobial activity of compound 1 was moderate that kill only S. aureus with MBC of 250 mu g/mL while other compounds especially compound 4 showed a broader activity that kill all tested bacteria.