A new benzophenone from Dobinea delavayi.

A new benzophenone sesquiterpene dobiniside A ( 1), together with two known compounds, 4′,6-dihydroxy-2,3′,4-trimethoxybenzophenone ( 2) and mangiferin ( 3), were isolated from the root of Dobinea delavayi. The structure of the new compound was determined on the basis of spectroscopic analysis, including 1D, 2D NMR, and FAB-MS techniques as well as by comparison of the spectral data with those of related compounds reported in the literature. Compounds 1-3 were screened for antitumor activity in vitro, and compound 3 was shown to possess antitumor activity with IC value of 7.4 × 10 μM for A-549. [ABSTRACT FROM AUTHOR]