COMPOSITION OF HERB AND SEED OIL AND ANTIMICROBIAL ACTIVITY OF THE ESSENTIAL OIL OF TWO VARIETIES OF OCIMUM BASILICUM HARVESTED AT SHORT TIME INTERVALS

Abstract

An experiment was conducted to study the changes in the chemical composition of the essential oil of two varieties of Ocimum basilicum over a period of six months at short harvest intervals for two crop seasons. In variety Vikarsudha, GC/MS analysis revealed the presence of eighteen essential oil constituents. Linalool (23.5­40.1% and 22.8­33.7%) and methyl chavicol (25.4­51.9% and 40.0­52.7%) were the major constituents in main and ratoon crops. Similarly, in variety Kuhmohak GC/MS analysis revealed the presence of linalool (19.2­25.4 % and 16.1­31.3%) and methyl chavicol (34.7­53.4% and 39.4­59.2%) in large quantities in main and ratoon crops, respectively. β myrcene, limonene, 1,8 cineole, ocimene, camphor, terpinen-4-ol, bornyl acetate, eugenol, methyl eugenol, β elemene, β caryophyllene, α humulene, γ Cadinene and cadinol were present in small quantities. Results pertaining to the zone of inhibition in the antimicrobial activity of essential oil indicated that Chromobacterium violaceum is more sensitive compared to Staphylococcus aureus. Among the fungal strains Aspergillus niger was found to be more sensitive. GC-MS analysis of the fixed oils obtained from the seeds in the ratoon crop revealed the presence of unsaturated and saturated fatty acids. The unsaturated fatty acids averaged 89% consisting of α-linolenic (49.3%­52.4%), linoleic (23.4%­26.0%), and oleic (10.3%­12.3%) acids. The most abundant saturated fatty acids were palmitic and stearic acids.

Keywords

• Ocimum
• Lamiaceae
• Eugenol
• β caryophyllene
• methyl eugenol
• relative humidity