Synthesis of α - mangostin-D-glucoside in supercritical carbon dioxide media.

α-Mangostin, the major xanthone constituent of mangoteen fruit pericarp, has several important pharmaceutical application but its bioavailability is restricted due to its insolubility in water. Herein, we synthesized water soluble α-mangostin-D-glucoside by glycosylation of α-mangostin at hydroxyl group; using amyloglucosidase (3.2.1.3) catalyzed reaction in supercritical carbon dioxide (SC-CO2) media. Response surface methodology (RSM) based on a five-variable central composite rotatable design involving 32 experiments was used to determine the effect of pressure (80-160 bar), temperature (35-75 °C), enzyme concentration (15-45 mg), buffer pH (4.0-8.0) and buffer volume (1.0-5.0 mL). Experimental data fitted the second-order polynomial equation as indicated by R(2) value of 0.94. The optimal enzymatic conversion within the experimental range of the variables reached 20.3 % at a pressure of 120 bar, temperature of 55 °C, enzyme concentration of 30 mg, buffer volume of 3 mL and pH 6.0 which is well matched with the predictive yield.