title: Chemical composition, antioxidant and antimicrobial activities of basil (Ocimum basilicum) essential oils depends on seasonal variations.
abstract: Chemical composition, antioxidant and antimicrobial activities of the essential oils from aerial parts of basil (Ocimum basilicum L.) as affected by four seasonal, namely summer, autumn, winter and spring growing variation were investigated. The hydro-distilled essential oils content ranged from 0.5% to 0.8%, the maximum amounts were observed in winter while minimum in summer. The essential oils consisted of linalool as the most abundant component (56.7-60.6%), followed by epi-α-cadinol (8.6-11.4%), α-bergamotene (7.4-9.2%) and γ-cadinene (3.2-5.4%). Samples collected in winter were found to be richer in oxygenated monoterpenes (68.9%), while those of summer were higher in sesquiterpene hydrocarbons (24.3%). The contents of most of the chemical constituents varied significantly (p<0.05) with different seasons. The essential oils investigated, exhibited good antioxidant activity as measurements by DPPH free radical-scavenging ability, bleaching β-carotene in linoleic acid system and inhibition of linoleic acid oxidation. Evaluation of antimicrobial activity of the essential oils and linalool, the most abundant component, against bacterial strains: Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pasteurella multocida and pathogenic fungi Aspergillus niger, Mucor mucedo, Fusarium solani, Botryodiplodia theobromae, Rhizopus solani was assessed by disc diffusion method and measurement of determination of minimum inhibitory concentration. The results of antimicrobial assays indicated that all the tested microorganisms were affected. Both the antioxidant and antimicrobial activities of the oils varied significantly (p<0.05), as seasons changed.
authors.affiliation: Department of Chemistry, University of Agriculture, Faisalabad 38040, Pakistan. Electronic address: ai.hussain@yahoo.com.
authors.forename: Abdullah Ijaz
authors.initials: AI
authors.lastname: Hussain
authors.affiliation: Department of Chemistry, University of Agriculture, Faisalabad 38040, Pakistan. Electronic address: fqanwar@yahoo.com.
authors.forename: Farooq
authors.initials: F
authors.lastname: Anwar
authors.affiliation: National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080, Pakistan. Electronic address: tufail_sherazi@yahoo.com.
authors.forename: Syed Tufail
authors.initials: ST
authors.lastname: Hussain Sherazi
authors.affiliation: Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta, Canada. Electronic address: roman.przybylski@uleth.ca.
authors.forename: Roman
authors.initials: R
authors.lastname: Przybylski
keywords: Antimicrobial; Aspergillus niger; GC–MS; IC(50); Linalool; Seasonal variation; Staphylococcus aureus