Chemical compositions of essential oils of some Kenyan Ocimum species

The natural aroma of Ocimum species varies, implying that variations in chemical compositions of their essential oils are likely to be observed. Steam distilled essential oils from leaves and flowers of Ocimum kenyense, Ocimum kilimandscharicum and Ocimum lamiifolium growing in various parts of Kenya were analyzed by gas chromatography-mass spectrometry (GC-MS). There were notable variations in individual composition of foliar and floral essential oils although some chemical constituents were common in investigated species. In O. kenyense, eucalyptol (20.01-24.81%) and estragole (22.01-35.06%) were identified as major compounds of its foliar and floral essential oils. Camphor (16.9-30.6%) and α-phellandrene (12.36-14.69%) were identified as major compounds of O. kilimandscharicum and O. lamiifolium, respectively. This study reports the existence of α-phellandrene chemo type of Kenyan O. lamiifolium species for the first time. Chemical compositions and percent mean yields of investigated Ocimum essential oils varied with species, plant organ used and agro ecological zones.