Aromatic plants of tropical central Africa. Part X Chemical composition of the essential oils of <i>Ageratum houstonianum</i> Mill. and <i>Ageratum conyzoides</i> L. from Cameroon

Abstract

Abstract The essential oils isolated from the leaves of Ageratum houstonianum Mill, and Ageratum conyzoides L. by hydrodistillation were analysed by GLC and GC‐MS. The essential oil of A. houstonianum contained 7‐methoxy‐2,2‐dimethylchromene (precocene I) and ageratochromene (precocene II) in almost similar amounts (32% and 24% respectively) whereas that of A. conyzoides was rich in precocene I (81%) and poor in precocene II (0.2%). Our findings are compared with those of the literature.