Absolute structure of resveratrol hexamers in Dipterocarpaceaeous plants

Abstract A resveratrol (Res) hexamer (vaticanol M ( 1 )) and two O -glucosides of 1 (vatcasides E ( 2 ) and F ( 3 )) and an epimer of 2 (vatcaside G ( 4 )) were isolated from three Vatica species— Vatica bantamensis , Vatica chinensis , and Vatica albiramis . The structures with a 3-(3,5-dihydroxyphenyl)-4,6-dihydroxy-2-(4-hydroxyphenyl)-2,3-dihydro-1 H -inden-1-yl group on the C-12 position of (−)-vaticanol B ( 5 ) were elucidated by spectroscopic analysis, including NMR experiments, conformational search by a MacroModel module, and circular dichroism data.