Composition of the concrete, absolute, headspace and essential oil,of the flowers of Michelia champaca Linn.

Extraction of fresh flowers of Michelia champaca L. with pentane afforded the concrete in 1.5 +/- 0.05% yield. Precipitating the waxes from the concrete with methanol gave absolute (80%). Distillation of the flowers in a Clevenger-type apparatus furnished the essential oil in 0.03% yield. The chemical composition of the concrete, absolute and essential oil were determined by GC and GC-MS and compared. The headspace volatile composition of flowers while still attached to the branch of the tree and after plucking was determined by solid phase micro-extraction on PDMS fibre and these results are also presented. Interestingly, the concrete and absolute. contained a much smaller amount of sesquiterpene hydrocarbons, which constitute more than 60% in the headspace. Most of the esters present in the concrete and absolute are not present in the essential oil, which on the other hand contains several monoterpene hydrocarbons not isolated from the pentane extract. The sesquiterpenes detected in the headspace are present in the essential oil. Copyright (c) 2006 John Wiley & Sons, Ltd.