Extraction and GC-MS Analysis of the Essential Oil from the Peel of Solanum incanum and its Antibacterial Activity Studies

摘要

Phytochemicals were extracted from the peel of Solanum incanum (S. incanum) with methanol (70% v/v). The phytochemical screening of the methanolic extract showed the presence of glycosides, steroids, terpenoids, flavonoids, tannins, alkaloids, saponins and phenolic compounds. The successive partitioning of the methanolic extract was carried out with three solvents hexane, diethyl ether and ethyl acetate. The diethyl ether fraction yielded two immiscible fractions. The oil was separated as essential oil fraction and analyzed by GC-MS (gas chromatography-mass spectrometry). The GC-MS analysis of the essential oil indicated 17 compounds including 2,3-butanediol (76.76%), diethyl phthalate (8.32%), benzyl benzoate (3.02%), 2,6-dimethyl-6-nitro-2-hepten-4-one (2.56%) and l,2-dimethoxy-4-(l-propenyl)benzene (1.88%). Among them, the mass spectral patterns of three compounds were analyzed, discussed and confirmed with NIST database. The antibacterial study of essential oil was conducted using four pathogens (E. coli, K. pneumonia, S. aureus and S. pyogenes) at four different concentrations (250, 500, 750 and 1000 μg/mL). The result indicates that the essential oil extracted from the peel of Solanum incanum exhibited remarkable antibacterial activity against E. coli and K. pneumonia in 1000 μg/mL, respectively compared with the positive control gentamicin (10 μg/mL). The result of this study revealed the presence of various organic components and the antibacterial activity of this plant essential oil may be as a result of the major compounds.