Piceatannol derivatives from Rheum austral D. Don and their chemotaxonomic significance

This paper reports the isolation and characterization of seven piceatannol derivatives (1-7), including two new compounds (4 and 6), along with resveratrol (8) and polydatin (9), from the underground parts of Rheum austral D. Don collected from Tibet. The structures of the isolates were identified based on analysis of their spectroscopic data and comparison with literature. Compounds 3-7, piceatannol-4′-O-glucopyranoside and its 6″-O-acylated derivatives reported in this study may be useful chemotaxonomic markers for R. austral collected from Tibet.