Detection and Primary Analysis of Antibacterial Activity in the Ethyl Acetate Extract of Lantana camara L. Leaves.

Lantana camara L. is generally considered an invasive plant species throughout the world. Research works carried out in recent years have proved its significance as a source of antimicrobial lead molecules. The aim of this research was to identify the antibacterial substance(s) in this plant species found locally and to test its antibacterial effect against selected bacterial strains. Plant samples were collected from the University of Dhaka campus. Ethanol and ethyl acetate extracts of the plant leaves were tested against Escherichia coli, Bacillus subtilis, Pneumococcus and Klebsiella. Both the ethanol and the ethyl acetate extracts showed significant activity against Bacillus subtilis. In disk diffusion antibacterial assay, ethanol extract showed greater activity than ethyl acetate extract against Bacillus subtilis and the zones of inhibition were 14 mm and 12 mm respectively. However, ethyl acetate extract showed greater activity than ethanol extract in TLC bioautography assay. Ethyl acetate and ethanol extracts showed very little activity against Pneumococcus and Klebsiella, but no antibacterial potential against Escherichia coli. Fractionation of the ethyl acetate extract by TLC and bioautography detection of antibacterial activity in TLC encouraged further purification of the lead active compound(s). Phytochemical composition analysis of the ethyl acetate extract showed the presence of alkaloids, steroids, phenolic compounds and glycosides.