Isolation and characterization of new 17-ketosteroid as antimicrobial agent from Vanda Tessellata (Roxb.) hook
The present study deals with isolation and identification of new 17-ketosteroid as antimicrobial agent from Vanda tessellata, an orchid. Three unknown compounds VT-1 in pure, VT-2 and VT-3 in semi pure form has been isolated. The antimicrobial activity of the isolated compounds was determined by agar-well diffusion method, MIC by broth dilution method and MBC was done by sub culturing relevant sample. Compounds VT-1 indentified as 3-Ethoxy-10, 13 Dimethyltetradecahydro-1H-Cyclopenta[a] Phenanthre-17(2H)-one,VT-2 and VT-3 were isolated first time and VT-1 showed significant antibacterial activity against Escherichia coli (16.66±0.47), Proteus mirabilis (15.66±0.47) and Bacillus subtilis (14.00±0.00) and less antifungal activity against Candida albicans (10.66±0.47) and Aspergillus niger( 10.66±0.47) then VT-2 and VT-3 .Compound VT-2 gives (12.33±0.47) against Candida albicans and VT-3( 14.33 ±0.47)zone of inhibition against Aspergillus niger respectively.Therefore, VT-2 and VT-3 are good antifungal compound then VT-1.The lowest MIC and MBC recorded were 0.002 mg/ml and 0.125 mg/ml.
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