Chemical Constituents of Datura stramonium L. Leaves and Its Antibacterial Activity against Human Pathogenic Bacteria

Abstract

The study of natural products has had a number of rewards. It has led to the discovery of a variety of useful drugs for the treatment of diverse ailments. The present study was phytochemical screening of the major secondary metabolites and evaluating their antibacterial activities of the crude extracts of Datura stramonium L. leaves. Extraction was done successively by maceration of leaf powder using petroleum ether, chloroform and methanol as solvents. Phytochemical screening was performed by various qualitative and quantitative methods. Antimicrobial activities of the crude extracts were determined by Agar well diffusion method against Staphylococcus aureus, Shigella boydii, Streptococcus agalactiae and Klebsiella pneumonia. The result of phytochemical analysis showed the presence of alkaloid, flavonoids, saponins, steroid, tannin and terpenoids and absence of quinones. Quantitative analysis of some of the detected phytochemicals showed saponins (44.61 mg/g) and alkaloids (39.10 mg/g) were dominant compounds followed by flavonoids (34.71 mg/g) and terpenoids (32.34 mg/g). Results of antibacterial assay revealed that extracts of the plant leaves showed inhibitory activity against the tested bacterial pathogens. Maximum inhibition was recorded against Streptococcus agalactiae (20.15±0.28 mm) and minimum inhibition against S. aureus (7.35±0.14 mm). Based on this results it is concluded that leaf extracts of the tested plant have the major secondary metabolites and antibacterial activities against the tested bacterial isolates.