Abstract:
Hydro-distilled volatile oils from the leaves of
Ocimum gratissimum
L. (Lamiaceae) from Meru district in
Eastern Kenya were analysed by gas chromatography-mass spectrometry (GC-MS) and also evaluated
for antimicrobial activity. The oil was dominated by monoterpens which accounted for 92.48%. This
monoterpene fraction was characterized by a high percentage of eugenol (68.8%). The other major
monoterpenes were methyl eugenol (13.21%), cis-ocimene (7.47%), trans-ocimene (0.94%),
-pinene
(1.10%) and camphor (0.95%). The sesquiterpenes present in fairly good amounts were germacrene D
(4.25%) and trans-caryophyllene (1.69%). The minor sesquiterpenes were
-farnesene (0.85%) and
-
bisabolene (0.74%). The antimicrobial activities of the essential oils were evaluated against both Gram
positive (
Staphylococcus aureus, Bacillus
spp.) and Gram negative (
Escherichia coli, Pseudomonas
aeruginosae, Salmonella typhi, Klebisiella pneumoniae, Proteus mirabilis
) bacteria and a pathogenic
fungus
Candida albicans
. The oil had pronounced antibacterial and antifungal activities on all the
microbes.
