Study of Biological Activity of Extract and Carboxylic Acids Isolated from Citrus aurantifolin Fruit on Growth of Some Gram Positive and Negative Bacteria

Abstract

In this research work, the alcoholic extract was isolated from Citrus aurantifolia (fruit). The carboxylic acids were isolated from alcoholic extract and the inhibitory effect of these compounds were investigated on the growth of six types of bacteria, which were: Staphylococcus aureus, Bacillus subtilis, Klebsiella Pneumoniae, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi, two antibiotics (Chloramphenicol and Ciprofloxacin) were used as a control. Citric acid was isolated by column chromatography packed with activated silica gel was used for fractionation of the compounds aforesaid from plant extract, then identificated by thin layer chromatography (TLC plate), Rate of flow (Rf) value. Isolated compounds showed better inhibiting effect than control samples, alcoholic extract showed strong inhibiting effect on all types of bacteria under study compared with control samples. Carboxylic acids showed inhibitory effect (but less than alcoholic extract) on S. typhi, Staph. aureus and B. subtilis equal to control samples, it showed less and varying effect on K. pneumoniae, E. coli and Ps. aeruginosa than control samples.