Chemical Composition of the Essential Oil of Trianthema portulacastrum L. Aerial Parts and Potential Antimicrobial and Phytotoxic Activities of its Extract

The essential oil of the aerial parts of Trianthema portulacastrum L. was analyzed by gas chromatography/ mass spectrometry. Fourty four compounds were identified, representing (2.27 % of the oil. Terpenes represent the major constituents (72.98 %) including monoterpenes (35.69 %), sesquiterpenes (30.75 %) and diterpene derivates 96.54 %). The major chemical constituents were hexahydro-farnesyl acetone (27.57 %), verbenene (12.32 %), incensole acetate (6.54 %), 3-p-manthane (2.88 %), cis-carvyl propanoate (1.98 %), trans-p-mentha-2,8-dien-ol (1.91 %). The alcoholic extract showed significant antifungal activity and moderate antibacterial activity. The plant extract at 6 mg ml(-1) inhibited the germination of Brassica tournefortii, Cenchrus echinatus and Lactuca sativa by 69.8 %, 82.2 % and 100 %, respectively. The seedling growth of these plants was also inhibited in a concentration-dependent manner. The radicle of the three tested plants was highly sensitive to allelochemicals. The allelopathic activity of T. portulacastrum could be used in controlling these noxious weeds (B. tournefortii and C. echinatus) as an ecofriendly bio-herbicide.