[Chemical constituents of Carya cathayensis and their antitumor bioactivity].

To investigate the chemical constituents of Carya cathayensis and their antitumor bioactivity. The compounds were isolated by Sephadex LH-20 and silica gel column chromatography. Their structures were identified by physicochemical properties and spectroscopic analysis. Then their cytotoxic activity was studied. Five compounds were elucidated as chrysophanol (1), physcion (2), beta-sitosterol (3), pinostrobin(4), 4,8-dihydroxy-1-tetralone (5). Compounds 2 and 5 are isolated from Carya cathayensis for the first time. In the MTT antitumor experiments, the compounds 1,4 and 5 have the cytotoxic activity to KB cell.