Megastigmanes and flavones from Polyalthia thorelii collected in Nam Dong, Thua Thien Hue

Polyalthia thorelii (Pierre) Fin. ex Gagnep. has been used as a traditional medicine for the treatment of stomachache. The present study describes the isolation and structural elucidation of five compounds from the methanol extract of the aerial parts of P. thorelii. Their structures were identified as: grasshoper ketone (1), ampelopsisionoside (2), (6S,9S)-roseoside (3), quercetin-3-rutinoside (4), and quercetin-3-O-beta -D-glucopyranoside (5) by spectroscopic analyses and comparison with the data reported in the literature. To the best of our knowledge, compounds 1 and 3 were isolated from genus Polyalthia and remain compounds were isolated from P. thorelii for the first time.