Constituents of Cajanus cajan (L.) Millsp., Moringa oleifera Lam., Heliotropium indicum L. and Bidens pilosa L. from Nigeria.

The essential oils of four plant species from Nigeria have been extracted by hydrodistillation and analyzed by GC and GC-MS. The oils of Cajanus cajan were comprised of sesquiterpenes (92.5%, 81.2% and 94.3% respectively in the leaves, stem and seeds). The major compounds identified were alpha-himachalene (9.0-11.5%), beta-himachalene (8.0-11.0%), gamma-himachalene (6.9-8.1%), alpha-humulene (7.1-8.7%) and alpha-copaene (4.5-5.6%). However, monoterpenoid compounds (81.8%) dominated the oil of Moringa oleifera with an abundance of alpha-phellandrene (25.2%) and p-cymene (24.9%). On the other hand, aldehydes (52.8%) occurred in the highest amount in Heliotropium indicum, represented by phenylacetaldehyde (22.2%), (E)-2-nonenal (8.3%) and (E, Z)-2-nonadienal (6.1%), with a significant quantity of hexahydrofarnesylacetone (8.4%). The leaf and stem oils of Bidens pilosa were dominated by sesquiterpenes (82.3% and 59.3%, respectively). The main compounds in the leaf oil were caryophyllene oxide (37.0%), beta-caryophyllene (10.5%) and humulene oxide (6.0%), while the stem oils had an abundance of hexahydrofarnesyl acetone (13.4%), delta-cadinene (12.0%) and caryophyllene oxide (11.0%). The observed chemical patterns differ considerably from previous investigations.