Mono- and sesquiterpenoids of the volatile oil ofBursera graveolens

Abstract

The characteristic spicy, sweet and balsamic aroma components of the woods of Bursera graveolens (palo santo) were measured using GC-MS. The characteristic four compounds, 1–4, were isolated from the diethyl ether extract. The structure of compounds 1 and 2 was elucidated by means of NMR studies, and confirmed to be 1-acetyl-4-isopropenyl-1-cyclopentene (1) and 2-methyl-5-isopropenyl-1-cyclopenten-1-carboxaldehyde (2) by synthesis from limonene oxide derivatives. The structure of compounds 3 and 4 was determined to be 6,10-epoxy-7(14)-isodaucane (3) and 10-hydroxy-6,10-epoxy-7(14)-isodaucane (4) by NMR experiments. Of these, compound 4 is a new sesquiterpenoid with a weak woody note, and the presence of compounds 1–4 in B. graveolens is reported here for the first time. Copyright © 2005 John Wiley & Sons, Ltd.