Phytochemical and antimicrobial studies on Artemisia monosperma

The use of natural products with therapeutic properties is as ancient as human civilization and, for a long time, mineral, plant and animal products were the main source of drugs. Herbal medicines used to treat many diseases including several infections. The present study deals with the isolation and identification of flavonoids from the aerial part of Artemisia monosperma and evaluation of the antimicrobial effects of a methanol-water (70:30) extract. This extract of A. monosperma was subjected to repeated chromatography on polyamide, cellulose and Sephadex LH-20 resulting in, quercetin 3-O-β-glucopyranoside, quercetin 5-O- β -glucopyranoside, isorhamnetin 5- O-β-glucopyranoside, 5,4′-dihydroxy 6,7-dimethoxy flavone, 5,4-dihydroxy 6,7, 3′-trimethoxy flavone, quercetin and isorhamnetin. The structures of the isolated compounds was elucidated on the basis of spectral analysis. The hydroalcoholic extract of the aerial part of A. monosperma exhibited variable degrees of antimicrobial activity (diffusion method). The extract shows a moderate activity against Escherichia coli and Bacillus cereus (20mm diameter) and low activity against Bacillus subtilis (16mm diameter) compared with that exerted by antibiotics (MIC,1.020–3.05mg/ml). It was found inactive against Staphylococcus aureus and Streptococcus pyogens [1,2].

References: [1] Zhu X, Zhang H, Lo R. (2004) J. Agric. Food Chem. 52: 7272–7278, [2] Chacha M, Bojase-Moleta G, Majinda RRT. (2005) Phyt. 66: 99–104.