Abstract:
In this study, Spirogyra spp. was screened for its phytochemical constituents and antibacterial activity. The fine algal powder was sequentially extracted by using petroleum ether, chloroform, acetone and methanol. The resulting extracts were subjected to qualitative phytochemical analysis and for their antibacterial activity against Escherichia coli, Salmonella thyphimurium, Pseudomonas aeruginosa and Staphylococcus aureus by Disc diffusion method. Phytochemical analysis showed the existence of bioactive compounds such as terpenoids, tannins, flavonoids, saponins. In vitro screening of crude petroleum ether, chloroform, acetone and methanol extracts have shown activity in inhibiting the growth of bacterial spp. tested with difference in their inhibitory zone (10 to 16mm). Among the four crude extracts chloroform extract showed superior activity on bacterial growth inhibition. Four compounds (labeled as SP-1, SP-2, SP-3 and SP-4) were isolated from chloroform extract by column chromatography. Among those isolated compound SP-1 was fully characterized and SP-2 was partially characterized based on spectral data such as IR, 1H-NMR, 13CNMR and DEPT-135. The fully characterized compound has structural similarity with lutein. SP-1, SP-2 and SP-4 fractions of Spyrogyra spp. also results in the bacterial growth inhibition. This indicates that, green algae Spyrogyra spp. have varied source of pharmacologically active natural products.
