Absolute configuration of (+)-pinoresinol 4-O-[6-O-galloyl]-β-D-glucopyranoside, macarangiosides E, and F isolated from the leaves of Macaranga tanarius

A lignan glucoside, (+)-pinoresinol 4-O-[6 ''-O-galloyl]-beta-D-glucopyranoside (1), and two megastigmane glucosides, named macarangiosides E and F (2, 3), together with 15 known compounds (4-18) were isolated from leaves of Macaranga tanarius (L) Mull-Arg. (Euphorbiaceae). Their structures were elucidated by spectroscopic and chemical analyses. In addition, the absolute stereochemistry of macarangiosides B and C isolated previously from the same plant was also determined for the first time. Compounds I and 2 were galloylated on glucose and possessed potent DPPH radical-scavenging activity. (C) 2009 Elsevier Ltd. All rights reserved.