Constituents of the flower essential oil ofAgeratina adenophora (Spreng.) K. et R. from India

Abstract

The flower essential oil of Ageratina adenophora (Spreng.) of North Indian origin consists of 66% of monoterpenes and 28% of sesquiterpenes. Sixty-four constituents were identified by their 1H-NMR spectra and GC–MS. Amorphene derivatives (10%), which are significant for A. adenophora, are main constituents of the sesquiterpene part. The structure of three novel natural products, amorpha-4,7(11)-diene, 5,8-epoxyamorpha-3,7(11)-diene and amorpha-4,7-dien-11-ol, was confirmed by their 1H- and 13C-NMR data. Some confusion in the literature concerning not only the stereochemistry of amorph-4-en-7-ol and muurol-4-en-7-ol but also the structure of amorph-4-en-3,8-dione and muurol-4-en-3,8-dione (‘eupatorenone’) was clarified. © 1997 John Wiley & Sons, Ltd.