Mst.Jesmin Sultana, Fazle Rabbi Shakil Ahmed
Biomedical Science and Engineering. 2014, 2(1), 1-4DOI:
Abstract: The fresh stem of the plant Swertia chirata Ham was extracted by rectified spirit. The crude rectified spirit extract was fractionated by using standard chromatographic techniques, on alumina gave several fractions (A, B, C, D, E & F). Fraction D, when subjected to column chromatographic analysis on neutral alumina, yielded a pure compound X-1 m.p. 180°C. X-1 was screened for its antibacterial activities against 12 pathogenic bacteria, 6 Gram positive and 6 Gram negative, by disc diffusion method at a concentration of 200 μg/disc. The results obtained were compared with those for a standard antibiotic Kanamycin. X-1 showed significant activity against Bacillus megaterium (13 mm), Bacillus subtilis (11 mm), Salmonella typhi-A (12 mm), Shigella flexeneriae (12 mm) and Klebsiella sp (13 mm) but a little activity against Staphylococcus aureus. The Minimum Inhibitory Concentrations (MIC) of X-1 determined against Bacillus megaterium and Salmonella typhi-A were 128 μg/ml and 132 μg/ml, respectively when tested in a nutrient broth medium. X-1 also showed significant activity against the brine shrimp (Artemia salina) nauplii (LC50 value of 10 μg/ml), in which the mortality rate increased with the increasing concentration of the compound, suggesting a positive correlation between brine shrimp toxicity and cytotoxicity.