Enzymatic Synthesis of Novel and Highly Soluble Puerarin Glucoside by Deinococcus geothermalis Amylosucrase.

Puerarin (daidzein-8- C -glucoside) is an isoflavone isolated from several leguminous plants of the genus Pueraria . Puerarin possesses several pharmacological properties; however, the poor solubility of puerarin limits its applications. To resolve this poor solubility, Deinococcus geothermalis amylosucrase ( Dg AS) was used to modify puerarin into more soluble derivatives. The results showed that Dg AS could biotransform puerarin into a novel compound: puerarin-4'- O - α -glucoside. The biotransformation reaction was manipulated at different temperatures, pH values, sucrose concentrations, reaction times, and enzyme concentrations. The results showed that the optimal reaction condition was biotransformed by 200 μg/mL Dg AS with 20% ( w / v ) sucrose at pH 6 and incubated at 40 °C for 48 h, and the optimal production yield was 35.1%. Puerarin-4'- O - α -glucoside showed 129-fold higher solubility than that of puerarin and, thus, could be further applied for pharmacological use in the future.