Isolation, partial purification and evaluation of bioactive compounds from leaves of Ageratum houstonianum

The present study deals with the isolation and partial purification of bioactive compounds from the crude methanol extracts of the leaves of Ageratum houstonianum (Asteraceae). The quantification and the identification of compounds in the crude extract and active bands isolated by preparative TLC were accomplished using GC-MS analysis. The most important compounds identified in the crude extract and active bands (AB-1 and AB-2) were 6-acetyl-7-methoxy-2, 2-dimethylchromene, hexadecanoic acid and squalene, respectively. Crude extract and active bands (AB-1 and AB-2) were investigated for their antibacterial activity against Staphylococcus epidermidis, Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The crude extract, AB-1 and AB-2 showed maximum zone of inhibition (10-13 mm) against Staphylococcus epidermidis, however, the antibacterial potential of active bands was slightly higher as compared to the crude extract. Dose-dependant increase in antioxidant potential was noticed in crude extract as well as with both active bands measured by DPPH free radicals, ion chelation and total antioxidants capacity. Our study reports various bioactive compounds in the leaves of the A. houstonianum with significant antioxidant and antibacterial potential.