Chemical compositions of fresh volatiles aromas of some Kenyan Ocimum species

Plants of genus Ocimum have unique aromas hence the likelihood of chemical profiles of their fresh volatiles being different. Gas Chromatography-Mass Spectrometry (GC-MS) analysis of head space volatiles of fresh aerial parts of O. kenyense, O. kilimandscharicum and O. lamiifolium species led to identification of four major classes of chemical constituents namely; monoterpenoids (15.16-56.01%), benzenoids (16.68-43.41%), sesquiterpenoids (3.35-22.77%) and non-terpenoids (7.62-15.62%). Fresh aromas of O. kenyense species from Laikipia and Nyeri Counties contained major constituents such as β-pinene (13.0-13.3%), p-ethylacetophenone (9.65-11.3%), p-methoxyacetophenone (8.74-11.6%), eucalyptol (6.10-8.80%) and ethyl isovalerate (7.62-7.80%). Limonene (9.94%) and camphor (19.4%); and eucalyptol (19.93%) and linalool (19.2%) were identified as major constituents of O. kilimandscharicum species from Kirinyaga and Nyeri Counties, respectively. α-Phellandrene (11.92%), limonene (7.65%) and (E)-β-ocimene (7.04%) were identified as major constituents of O. lamiifolium species (Nyandarua County) while α-phellandrene (18.69%) and β-sabinene (15.73%) were identified as major compounds of O. lamiifolium species (Nakuru County).