Antibacterial and free radical scavenging activity of a medicinal plant Solanum xanthocarpum

摘要

The present study describes the phytochemical profiles, antibacterial, and antioxidant properties of different solvent extracts of Solanum xanthocarpum leaves. Phytochemical analysis results revealed the presence of terpenoids, tannins, steroids, and phenols. Methanolic extract of plant had a maximum quantity of phenol (28.3 +/- 2.0mg) and flavonoids (25.2 +/- 1.2mg) than others. Similarly, the methanolic extract showed excellent antibacterial activity and exhibited the highest inhibitory effect against Pseudomonas aeruginosa (12 +/- 0.5mm), Salmonella typhi (10 +/- 0.6mm), Staphylococcus aureus (9 +/- 1.0mm), and Escherichia coli (7 +/- 1.3mm). The average minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were reported in the range of 3.2 to 6.9 mu g/ml (for MIC) and 6.0 to 14.5 mu g/ml (for MBC), respectively. The remarkable antioxidant activity was observed in chloroform and methanol extract on the DPPH radical scavenging activity with the lowest IC50 value of 197.245 g/ml (chloroform) and 201.04 g/ml (methanol) and compared with control (ascorbic acid 239.36 g/ml). GC-MS analysis revealed the presence of six major bioactive compounds as follows; 2,Octylcyclopropene-1-Heptanol (42.81%), Hexadecanoic acid (26.63%), 1-methylene-2b Hydroxymethyl-3,3-Dimethyl-4b-(3Methylbut-2enyl)-C (9.3%), Phytol (7.5%), (1,3,3-Trimethyl-2-Hydroxymethyl-3,3-Dimethyl-4-3-Methylbut-2-Enyl)-C (7.2%). 3,7,11,15-Tetramethyl-2-Hexadecen-1-Ol (6.3%). The FT-IR spectrum reflected the presence of the twelve peaks at the range of 3746.38 cm-1 (O-H stretch alcohols), 3424.18 cm-1 (O-H stretch phenols), 2926.01 cm-1 (C-H stretch alkanes), 2857.55 cm-1 (C-H stretch alkanes), 2084.04 cm-1 (-C=C stretch alkynes), 1595.76 cm-1 (N-H bend primary amines), 1402.49 cm-1 (C-C stretch in ring aromatics) and others. This study suggests S. xanthocarpum as a potential candidature for having better antibacterial and antioxidant property and identified several bioactive compounds by GC-MS analysis.