Cytotoxic compounds from the stems of Diospyros ehretioides and their bioactivity.

A new (naphthalenyl)methyl acetate, (1,4,5-trimethoxynaphthalen-2-yl)methyl acetate (1) and (±)-4,5-dihydroxy-2-methyltetralone (2) were isolated together with five lupane triterpenes (3-7), naphthoquinone derivatives (8-13), coumarins (14 and 15) and a vanillic acid (16) from the stems of Diospyros ehretioides. Their structures were established through spectroscopic analysis, IR, 1D and 2D NMR. Both 1 and 2 displayed significant cytotoxicity against three cancer cell lines including HeLa, HCT116 and MCF-7, with IC₅₀ values in the range of 5.05-15.90 µg/mL, while 16 exhibited moderate cytotoxicity against HeLa and HCT116 cell lines and was not toxic to Vero cells.