Antimycobacterial activity of two natural alkaloids, vasicine acetate and 2-acetyl benzylamine, isolated from Indian shrub Adhatoda vasica Ness. leaves

In folk medicine, Adhatoda vasica Ness. (Acanthaceae) is used to treat asthma and cough. The leaves of A.vasica were powdered and extracted with hexane, ethyl acetate and methanol. The hexane extract showed 97% reduction in colony-forming units (CFU) at 100 mu g/ml. The hexane extract was subjected to column chromatography. Two natural compounds, vasicine acetate and 2-acetyl benzylamine, were isolated from it. They were bioassayed against Mycobacterium tuberculosis. The two compounds showed strong antimycobacterial activity. Vasicine acetate and 2-acetyl benzylamine isolated from hexane extract of A.vasica leaves, significantly inhibited M. tuberculosis and one multi-drug-resistant (MDR) strain and one sensitive strain at 200 and 50 mu g/ml, respectively. Our study demonstrated that both the compounds, vasicine acetate and 2-acetyl benzylamine, could be evaluated further for developing a drug to control M. tuberculosis.