Composition and antioxidant capacity of the essential oil of leaves of Vitex megapotamica (Sprengel) Moldenke.

This study is designed to examine the chemical composition and antioxidant activity of the essential oil of Vitex megapotamica. Gas chromatography-mass spectrometry analysis resulted in the detection of 27 components, representing 92.36% of the total oil composition. The main components in the oil were butylated hydroxytoluene (BHT) (34.17%), phytol (12.66%), α-caryophyllene (11.84%), δ-elemene (10.65%), β-caryophyllene (7.82%), γ-elemene (4.24%) and germacrene D (2.82%). The antioxidant activity of the oil was evaluated in terms of their free-radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl. The oil showed percentage inhibition of 35.62% and 75.25% at concentrations of 76 and 101.6 mg mL(-1), respectively. BHT (36.30%) was also determined by HPLC-DAD in the hexane fraction from the leaves. To the best of our knowledge, this is the first study of the composition and antioxidant activity of the essential oil of the species V. megapotamica.