Evaluation of antimicrobial and antioxidant activity of essential oil of Trianthema decandra L.

Essential oils are promising sources of antimicrobial activity. Essential oil was isolated from chloroform leaf extract of Trianthema decandra using column chromatography and analysed by gas chromatography/mass spectrometry (GC/MS). 23 components were identified, representing 99.98% of oil. The major components of T. decandra oil were Eicosane (18.81%), Tetracosane (16.17%), Hexadecane (14.84%), Dotriacontane (8.17%), Nonacosane (7.13%), Tetrapentacosane (5.61%), Henelcosane (4.34%), 2,4-Di-tert-butylphenol (2.92%), Bis (2-ethyl hexyl) phthalate (2.74%) and Phytol (2.19%). The oil has lower contents of 4,6-Dimethyldodecane (0.83%), 3,7-Dimethyldecane (0.77%), 3,4,5,6-Tetramethyloctane (0.64%), 3-Ethyl-3-methylheptane (0.35%), 3,8-Dimethylundecane (0.29%). The essential oil showed the Diameter of Inhibition Zone (DIZ) ranging from 19 ± 0.01 to 24 ± 0.05 mm at a concentration level of 1 mg/disc in all the twelve strains tested. Chloramphenicol and nystatin have shown DIZ ranging from 18 ± 0.05 to 23.6 ± 0.02 mm at a concentration of 30 μg/disc. The minimal inhibitory concentration (MIC) of essential oil against bacterial and fungal strains was in the range of 625-1250 μg/ml. Total phenolic contents of essential oil was 72.4 ± 1.26 mg/g weight of essential oil which was expressed as GAE. The antioxidant activity assays of the essential oil used in the inhibition of the free radical 2, 2-diphenyl-1-picrylhydrazyl showed high inhibitory concentration values of 70.64 ± 0.05 mg/g.