Enzymatic biosynthesis of novel neobavaisoflavone glucosides via Bacillus UDP-glycosyltransferase / 中国天然药物

The present study was designed to perform structural modifications of of neobavaisoflavone (NBIF), using an in vitro enzymatic glycosylation reaction, in order to improve its water-solubility. Two novel glucosides of NBIF were obtained from an enzymatic glycosylation by UDP-glycosyltransferase. The glycosylated products were elucidated by LC-MS, HR-ESI-MS, and NMR analysis. The HPLC peaks were integrated and the concentrations in sample solutions were calculated. The MTT assay was used to detect the cytotoxic activity of compounds in cancer cell lines. Based on the spectroscopic analyses, the two novel glucosides were identified as neobavaisoflavone-4'-O-β-D-glucopyranoside (1) and neobavaisoflavone-4', 7-di-O-β-D-glucopyranoside (2). Additionally, the water-solubilities of compounds 1 and 2 were approximately 175.1- and 4 031.9-fold higher than that of the substrate, respectively. Among the test compounds, only NBIF exhibited weak cytotoxicity against four human cancer cell lines, with IC values ranging from 63.47 to 72.81 µmol·L. These results suggest that in vitro enzymatic glycosylation is a powerful approach to structural modification, improving water-solubility.

Biosynthesis of a new psoralidin glucoside by enzymatic glycosylation / 南方医科大学学报

<p><b>OBJECTIVE</b>To modify the structure of psoralidin using in vitro enzymatic glycosylation to improve its water solubility and stability.</p><p><b>METHODS</b>A new psoralidin glucoside (1) was obtained by enzymatic glycosylation using a UDP- glycosyltransferase. The chemical structure of compound 1 was elucidated by HR-ESI-MS and nuclear magnetic resonance (NMR) analysis. The high-performance liquid chromatography (HPLC) peaks were integrated and sample solution concentrations were calculated. MTT assay was used to detect the cytotoxicity of the compounds against 3 cancer cell lines in vitro. Results Based on the spectroscopic data, the new psoralidin glucoside was identified as psoralidin-6',7-di-O-β-D- glucopyranoside (1), whose water solubility was 32.6-fold higher than that of the substrate. Analyses of pH and temperature stability demonstrated that compound 1 was more stable than psoralidin at pH 8.8 and at high temperatures. Only psoralidin exhibited a moderate cytotoxicity against 3 human cancer cell lines. Conclusion In vitro enzymatic glycosylation is a powerful approach for structural modification and improving water solubility and stability of compounds.</p>