Abstract

• The aim of this research was to extract, isolate, determine the structure of isolated compound and its antimicrobial activity from the ethanolic tuber extract of Stephania glabra (Roxb.) Miers (Menispermaceae family). The tuber of Stephania glabra (Roxb.) Miers, Taung-Kya (Myanmar name) was selected for this present work. It was rinsed with tap water, chopped in to small pieces and dried in air. The prepared dry sample was extracted with 95% of ethanol for one month. After doing filtration and evaporation, the remaining extract mass was further extracted with ethyl acetate and ran by different solvents ratios using thin layer sheet (spot test on TLC plate). A biologically active pure compound (colourless needle shaped crystals) could be isolated from n-hexane and ethyl acetate solvent ratio (n-hex 1:1EtOAc, 400 mg, and Rf value 0.5) by passing through the prepared column chromatogram. The molecular formula of an unidentified palmatine compound was assigned as C21H25NO4 (assumed as glabrine) by using advanced spectroscopic techniques such as FT IR, 1D NMR (1H, 13C and DEPT), 2D NMR (HSQC, DQF-COSY, HMBC, NOESY) and DART MS spectral evidences. The antimicrobial activity of palmatine compound was examined by agar disc diffusion method against six selected organisms. This compound responds medium inhibition zone (15mm to 18mm) on all tested microorganisms, namely, Bacillus subtilis (NCTC 8236), Staphylococcus aureus (NCPC 6371), Pseudomonas aeruginosa (6749), Bacillus pumilus (NCIB 8982), Candida albicans and Escherichia coli (NCIB 8134). The IUPAC name of palmatine compound was named as (R)- 2, 3, 9, 12- tetramethoxy- 5, 8, 13, 13a- tetrahydro-6H- isoquinolino [2,1- b] isoquinoline.