Guaiane sesquiterpenes from Amoora rohituka.

The petroleum ether extract of the stem bark of Amoora rohituka afforded two novel guaiane-derived sesquiterpenoids, 6beta,7beta-epoxyguai-4-en-3-one (1) and 6beta,7beta-epoxy-4beta,5-dihydroxyguaiane (2). The structures of 1 and 2 were determined by extensive NMR and MS analyses and by comparison of their spectral data with related compounds. The relative stereochemistry of the asymmetric centers in 1 and 2, except at C-5 of 2, were determined by selective 1D-NOESY experiments. Copyright 2003 Elsevier Science Ltd.