Chemical constituents, antioxidant and antibacterial activities of essential oils of Ochna afzelii (R. Br. ex Oliv.) ( Aug 10.1080/10412905.2023.2243952, 2023 )

Essential oils (EOs) from Ochna afzelii leaves, stems and roots were extracted and characterised by hydrodistillation and Gas Chromatogragphy-Mass Spectrometry (GC/MS) techniques, respectively. Antioxidant activity was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH*) method while antibacterial activity was determined using agar well diffusion and broth microdilution methods. Leaf, stem, and root oils afforded thirteen, ten and seven compounds, respectively, which were characterized by a high percentage of oxygenated sesquiterpenes and sesquiterpene hydrocarbons. The major compound in O. afzelii leaf and root EOs was & beta;-Atlantol, while the O. afzelii stem EO had (E)-& beta;-ionone as its major compound. The leaf oil displayed highest antioxidant activity (IC50 = 238.14 & mu;L/mL). All the EOs showed antibacterial activities against Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, and Streptococcus pneumoniae, with the zones of inhibition and MIC values ranging from 12.0-18.0 mm and 2.5-10 & mu;L/mL, respectively. O. afzelii has a mild antioxidant effect, but can be a potential source of natural antibacterial agents.