title: Chemical composition, antioxidant and antibacterial activities of the leaf essential oil of Juglans regia L. and its constituents.
abstract: The essential oil from the leaves of Juglans regia L. (Juglandaceae) growing wild in Kashmir (India) was obtained by hydrodistillation and analysed by a combination of capillary GC-FID and GC-MS. A total of 38 compounds, representing 92.7% of the oil, were identified and the major components were found to be α-pinene (15.1%), β-pinene (30.5%), β-caryophyllene (15.5%) germacrene D (14.4%) and limonene (3.6%). The essential oil and the main individual constituents were screened for antibacterial activity and the essential oil evaluated for antioxidant activity. Antibacterial activity was evaluated using the disc diffusion and microdilution methods against a group of clinically significant Gram-positive (Staphylococcus epidermidis MTCC-435, Bacillus subtilis MTCC-441, Staphylococcus aureus) and Gram-negative bacteria (Proteus vulgaris MTCC-321, Pseudomonas aeruginosa MTCC-1688, Salmonella typhi, Shigella dyssenteriae, Klebsiella pneumonia and Escherichia coli). The essential oil and its major components exhibited broad spectrum inhibition against all the bacterial strains with Gram-positive being more susceptible to the oil than Gram-negative bacteria. Antioxidant activity of the oil was evaluated by the scavenging effect on DPPH (2,2-diphenyl-1-picrylhydrazyl) and hydroxyl radicals. In general, the essential oil exhibited high antioxidant activity which was comparable to the reference standards at the same dose (ascorbic acid and butylated hydroxyl toluene, BHT) with IC(50) values of 34.5 and 56.4μg/ml calculated by DPPH and hydroxyl radical scavenging assays respectively.
authors.affiliation: Indian Institute of Integrative Medicine, Srinagar, India. manzooriiim@gmail.com
authors.forename: Manzoor A
authors.initials: MA
authors.lastname: Rather
authors.forename: Bilal A
authors.initials: BA
authors.lastname: Dar
authors.forename: Mohd Yousuf
authors.initials: MY
authors.lastname: Dar
authors.forename: Bilal A
authors.initials: BA
authors.lastname: Wani
authors.forename: Wajahat A
authors.initials: WA
authors.lastname: Shah
authors.forename: Bilal A
authors.initials: BA
authors.lastname: Bhat
authors.forename: Bashir A
authors.initials: BA
authors.lastname: Ganai
authors.forename: Khursheed A
authors.initials: KA
authors.lastname: Bhat
authors.forename: Rajneesh
authors.initials: R
authors.lastname: Anand
authors.forename: Mushtaq A
authors.initials: MA
authors.lastname: Qurishi
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis*; D000975:Antioxidants / Q000032:analysis*; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D031324:Juglans / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D009822:Oils, Volatile / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D009822:Oils, Volatile