Antioxidant Activity and Chemical Composition of Essential Oils of Selected Cleome Species Growing in Saudi Arabia

Abstract

Antioxidant activity and chemical compositions of essential oils of Cleome rupicola Vicary, Cleome ramosissima Webb ex Parl. and Cleome amblyocarpa Barratte & Murb. growing in Saudi Arabia were investigated. GC–FID/MS analysis allowed the identification of 52, 57 and 74 compounds, comprising 98.63%, 91.19% and 99.10% of the oils, respectively. In C. rupicola oils, 2-Methyl butyl isothiocynate (42.16%) and cubenol (20.09%) were the major compounds. In the case of C. ramosissima, the major compounds were cubenol (18.20%) and 3E-cembrene (6.12%), whereas the major compounds of C. amblyocarpa were 2-methoxy-4-vinyl phenol (20.06%), cis-Dihydro carvone (13.09%) and β-cubebene (7.46%). Antioxidant activity of essential oils of the three Cleome species was examined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2^¢-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) and ferrous ion chelating activity assay. The results indicated that the essential oils extracted from the three species have good antioxidant activity