Isolation and identification of antibacterial compound from Indo–Himalayan Aconitum nagarum

ObjectiveTo isolate and identify the antibacterial compound from Aconitum nagarum Stapf., a little known medicinal plant in Manipur (Indo–Himalaya).MethodsThe enriched alkaloid extract from Aconitum nagarum root was fractionated through silica gel column chromatography and analysed for antibacterial activity against bacterial species including human pathogens, Staphylococcus aureus, Salmonella typhimurium, Escherichia coli and Bacillus subtilis. The most potent compound (F3C2) isolated from this fraction was purified by chromatography and identified by spectral (IR and NMR) analysis.ResultsAmong different fractions (F1-F6), ether fraction (F3) was found to have maximum antibacterial activity. Based on activity guided fractionation, the compound was identified as a diterpenoid alkaloid aconitine [(1α,3α,6α,14α,16β)–8–(acetyloxy)–20–ethyl–3,13,15–trihydroxy–1,6,16–trimethoxy–4–(methoxymethyl)aconitan–14–yl benzoate].ConclusionThe antibacterial compound showed activities against different human pathogens and has been identified as aconitine.