Enzymatic bioconversion of citrus hesperidin by Aspergillus sojae naringinase: enhanced solubility of hesperetin-7-O-glucoside with in vitro inhibition of human intestinal maltase, HMG-CoA reductase, and growth of Helicobacter pylori.

Hesperetin-7-O-glucoside (Hes-7-G) was produced by the enzymatic conversion of hesperidin by Aspergillus sojae naringinase due to the removal of the terminal rhamnose. Extracts from orange juice and peel containing the hesperidin were so treated by this enzyme that the hesperidin could also be converted to Hes-7-G. The solubility of Hes-7-G in 10% ethanol was enhanced 55- and 88-fold over those of hesperidin and hesperetin, respectively, which may make Hes-7-G more bioavailable. Hes-7-G was 1.7- and 2.4-fold better than hesperidin and hesperetin, respectively, in the inhibition of human intestinal maltase. Hes-7-G was more potent by 2- and 4-fold than hesperidin in the inhibition of human HMG-CoA reductase. Additionally, Hes-7-G exhibited more effective inhibition of the growth of Helicobacter pylori than hesperetin, while its effectiveness was similar to that of hesperidin. Therefore, the results suggest that bioconverted Hes-7-G is more effective and bioavailable than hesperidin, as it has enhanced inhibitory and solubility properties.