Chemical compositions of smoke volatiles of some Kenyan Ocimum species

The natural aroma of Ocimum species vary, implying that variations in chemical compositions of their smoke aroma are likely to be observed. Air entrained smoke volatiles from leaves and flowers of Ocimum kenyense, Ocimum kilimandscharicum and Ocimum lamiifolium species growing in various parts of Kenya were analyzed by gas chromatography-mass spectrometry (GC-MS). Chemical compositions of investigated Ocimum smoke volatiles varied with species and agro ecological zones. Five classes of chemical constituents namely; monoterpenoids (14.11-64.40%), benzenoids (3.04-38.2%), sesquiterpenoids (14.12-37.69%), triterpenoids (0.48-2.07%) and non-terpenoids (0.83-17.85%) were identified in this study. There were notable variations in individual chemical compositions of smoke volatiles although α-phellandrene (0.81-12.76%) was identified in all investigated Ocimum species. In O. kenyense, eucalyptol (10.71-27.93%) and estragole (18.32-30.93%) were identified as major compounds of its smoke volatiles. Camphor (12.62-17.32%) and α-phellandrene (8.41-12.76%) were identified as major compounds of smoke volatiles derived from O. kilimandscharicum and O. lamiifolium species, respectively. This study reports the smokes derived volatile chemical composition of O. kenyense, O. kilimandscharicum and O. lamiifolium species for the first time. The volatile chemical profiles of smokes of investigated Ocimum species provide a scientific basis for their traditional use as incenses and insect repellents.