ABSTRACT
OBJECTIVE: To study the chemical constituents of flavones from Uncaria sinensis. METHODS: The extract with 95% EtOH from the bard and branch with curved hooks of U. sinensis, was sequentially partitioned with petroleum ether, CHCl3, EtOAc and n-BuOH, respectively. Five flavones were isolated by column chromatography from EtOAc and n-BtOH parts, and their structures were identified by the spectral analysis of NMR and MS data. RESULTS: Five flaveones were isolated and their structures were identified as: quercetin (1), kaempferol (2), linarin (3), quercetin-3-O-β-D-galactopyranside (4), quercetin-3-O-α-L-rhamnopyranosyl-(1 → 6)-β-D-galactopyranoside (5). CONCLUSION: Compounds 1-5 were obtained from this plant for the first time. Copyright 2012 by the Chinese Pharmaceutical Association.