In Vitro and in Vivo Anti-Hyperglycemic Activities of Taxifolin and Its Derivatives Isolated from Pigmented Rice ( L. cv. Superhongmi).

Superhongmi is a new rice variety, which was developed for the enrichment of bioactive compounds through cross-breeding three varieties of rice breeds in Korea. The high-performance liquid chromatography coupled with a photodiode array detector quadrupole and tandem time-of-flight mass spectrometry (HPLC/PDA/QTOF-MS) analysis has revealed that superhongmi bran extract contained four taxifolin derivatives as well as cyanidin 3-glucoside. The high-performance countercurrent chromatography (CCC) and reversed-phase HPLC led to the isolation of aforementioned five compounds, and spectroscopic analysis identified cyanidin 3-glucoside (), along with (2,3)-taxifolin 3--β-d-glucopyranoside (), (2,3)-4'--methyltaxifolin 3--β-d-glucopyranoside (a novel compound) (), (2,3)-taxifolin (), and (2,3)-4'--methyltaxifolin (). Compound had the highest rat small intestinal sucrase inhibitory activity (0.54 mM) relevant for potentially managing postprandial hyperglycemia, followed by compound (0.97 mM) and compound (1.74 mM, IC). The anti-hyperglycemic effect of compound (taxifolin), a main peak in HPLC analysis was investigated using a Sprague-Dawley (SD) rat model. Compared to a control, taxifolin treatment ( < 0.001) reduced significantly after sucrose loading the observed postprandial blood glucose and the maximum blood glucose () by 15% (203.60 ± 15.86 to 172.30 ± 12.74). These results indicate that taxifolin derivatives that inhibit the activity of carbohydrate-hydrolyzing enzymes resulting in reduced dietary carbohydrate absorption can potentially be used as a strategy to manage diabetes.