(E)-Anethole as a Major Essential Oil Constituent of<i>Clausena anisata</i>

Abstract

ABSTRACT In the course of our comprehensive investigation of the oils of the leaves of Clausena anisata from three West African countries, we have observed that, on the basis of its oil constituents, C. anisata can be classified into three major chemovarieties. Two of these chemovarieties have been observed in collections in Ghana, Togo and Benin. One contains mainly methyl chavicol (80–100%), and between one and ten other constituents, while the other contains a large number of constituents (up to 50), varying in concentration from 0.2% to about 20%. These include limonene, β-phellandrene, β-caryophyllene, α-humulene and germacrene D. However, there is a third collection in Ghana, positively identified as C. anisata, which yields between 85–100% of(E)-anethole as its major essential oil constituent. The chemovariation does not appear to be dependent on seasonal or geographical factors. The plants containing either methyl chavicol or (E)-anethole give very high yields of oil while those with several constituents yield very low quantities of oil. These observations are of considerable chemotaxonomic significance and are also significant in regard to the possible commercial exploitation of the essential oils of C. anisata.