A new cytotoxic plumbagin derivative from roots of <i>Diospyros undulata</i>

Abstract

A new plumbagin derivative, 3-(5-oxohexyl)plumbagin (<b>1</b>), together with six known benzoquinone derivatives (<b>2</b>-<b>7</b>), four known triterpenoids (<b>8</b>-<b>11</b>) and coniferyl aldehyde (<b>12</b>) were isolated from <i>Diospyros undulata</i> roots. Their structures were elucidated by intensive spectroscopy including 1 D and 2 D NMR, UV, IR and MS spectrometric analysis. Compound <b>1</b> 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 µM, respectively. Moreover, it did not showed cytotoxicity to Vero cells. In addition, the antimicrobial activity of compound <b>1</b> was moderate that kill only <i>S. aureus</i> with MBC of 250 µg/mL while other compounds especially compound <b>4</b> showed a broader activity that kill all tested bacteria.