Absolute configuration of resveratrol oligomer glucosides isolated from the leaves of Upuna borneensis

Abstract A comprehensive investigation of the chemical constituents of the leaves of Upuna borneensis (Dipterocarpaceae) was performed. Three new glucosides of resveratrol oligomers having a pentameric aglycone [upunoside E ( 1 )] and dimeric aglycones [upunosides F ( 3 ) and G ( 4 )], as well as 14 resveratrol derivatives ( 2 , 5 – 17 ), were isolated. The absolute configurations of the new compounds were elucidated by spectroscopic analysis, including two-dimensional NMR and CD spectra.