full issue - Association of Biotechnology and Pharmacy

Current Trends in Biotechnology and PharmacyVol. 5 (1) 993-997 January 2011. ISSN 0973-8916 (Print), 2230-7303 (Online)995Phytochemical screening: Active extracts weretested for presence of alkaloids, flavones,phenolics, and flavonoids as described below (8,9).Alkaloids: Dragendorff reagent was used to testthe presence of alkaloids. The presence ofalkaloids was indicated by the appearance ofyellow precipitate when few drops of reagentwere added to the solution.Flavones: Test solution (500 µl) was mixed with100 µl of absolute alcohol, 0.02 g of p-dimethylamine benzaldehyde and two drops of conc. Hcl.Development of red or pink colour indicated thepresence of flavones.Flavonoids: An aqueous solution of the extractwas treated with 10% ammonium hydroxidesolution. Yellow florescence indicates thepresence of flavonoids.Phenols: Ferric chloride was used to test thepresence of phenols. The presence of phenolswas indicated by appearance of green colourationwhen the reagent was added to extract.Results and DiscussionResults of disc diffusion assay (table 1)indicated S. paratyphi A to be susceptible to allthe extracts tested against it. S. pyogenes, andS. auerus exhibited no notable susceptibility toany of the test extracts. Ethanol extract of P.sylvestris (50 mg/mL) produced same size ofinhibition zone as that produced by ethanol extractof T. dioica (100 mg/mL) against S. paratyphiA. As the former did it at exactly half theconcentration of the latter, it can be said to betwice as potent as the latter. Methanolic extractof P. sylvestris produced smallest zone of inhibitionagainst S. paratyphi A, despite its concentrationbeing higher than all other test extracts. Activityindex (AI) was calculated for the extracts whichexhibited activity in disc diffusion assay, as writtenin parentheses in table 1. Methanolic extract ofT. dioica registered highest values of AI againstS. paratyphi A, and P. oleovorans. As ethanolicextract of P. sylvestris was found to be effectiveagainst both gram-positive as well as gramnegativebacteria, it can be said to have a broadspectrum of activity (10). It was furtherinvestigated for its MIC values against susceptiblebacteria. It was capable of inhibiting the growthof S. paratyphi A, and S. epidermidis atconcentrations of 481 and 410 µg/mL, respectively(Table 2). It was found to be bacteriostatic inaction, as organisms were able to revive growthwhen transferred on nutrient agar free fromextract. Total activity of this extract against boththe organisms was above 100 mL/g. Total activityis a measure of the amount of material extractedfrom a plant in relation to the MIC of the extract,fraction or isolated compound. It indicates thedegree to which the active fractions or compoundspresent in 1 g can be diluted and still inhibitgrowth of the test organism (7). Phytochemicaltests indicated the presence of phenols, alkaloids,and flavones in ethanolic extract of P. sylvestrisseeds.ConclusionThis study indicated various extracts of P.sylvestris, and T. dioica seeds to possessantibacterial activity. These extracts should befurther investigated for identification of activeconstituent(s). Active constituent(s) onceseparated can be subjected to compatibletechniques such as mass spectrometry, IR andNMR spectroscopy for structural studies.AcknowledgementsAuthor thank Nirma Education andResearch Foundation (NERF) for financialassistance, Prof. Y. T. Jasrai (Botany Dept.,Gujarat University) for seed authentication, andProf. S. R. Dave (Microbiology Dept., GujaratUniversity) for providing one of the testorganisms.In vitro antibacterial activity in seed