Study On Substance Basis Of Anti - Hyperuricemia Of Polygonum Cuspidatum Based On Xanthine Oxidase Target

Gout is a metabolic disease of tissue damage due to long-term purine metabolic disturbance,rising serum uric acid. As the key enzyme of uric acid generation,xanthine oxidase is the target of drug action which can lower uric acid level. Polygonum cuspidatum Sielb. et Zucc is a member of the Polygonaceae family with medicinal parts are roots and rhizomes. In several studies,the researchers evaluated that the rhizome of Polygonum cuspidatum extraction can treat the gout by its strong inhibition of the enzyme xanthine oxidase and significantly reduce serum uric acid level of hyperuricemia rats. However,the active components which inhibited of activity of xanthine oxidase are still unknown and remain to be isolated and identified.This study established Polygonum cuspidatum extraction HPLC analysis method.by different chromatographic column,mobile phase and detection wavelength. Macroporous resins and reverse phase partition chromatography methods used to initial separation,and HPLC method analysis the effect of separation. As the result,macroporous resins method had fine separability. Used in vitro xanthine oxidase inhibitor experiment to find activity eluates,and the formation amount of uric acid in the xanthine-xanthine oxidase reaction system was determined by HPLC. All eluates have inhibitory activity except pure water eluate. 30% and 50% eluates have higher inhibitory activity, inhibition is 69.04±0.47% and 51.22±1.14% with concentration of 50 μg/mL.We separated eight compounds from 30% and 50% eluates by mcroporous resin column chromatography ODS column chromatography and HPLC separation technique and elucidated their structures by the data of UV,EI-MS,1H-NMR,13C-NMR,pieced(I),resveratrol(II),emodin-6-O-β-D-glucoside(III),torachrysone-8-O-β-Dglucopyranoside(IV),emodin-8-O-β-D-glucoside(V),physcion-8-O-β-D-glucoside(VI),emodin(VII),chrysophanol(VIII).Used in vitro xanthine oxidase inhibitor experiment to find activity compounds,six compounds have inhibitory activity. Resveratrol and torachrysone-8-O-β-Dglucopyranoside have higher inhibitory activity,IC50 is 91.04 μM and 54.31 μM. Based on the Lineweaver–Burk plots of different concentrations and the intersection of these lines,the inhibitory mode of resveratrol is competitive and torachrysone-8-O-β-Dglucopyranoside is noncompetitive. Xanthine oxidase inhibiting effect of torachrysone-8-O-β-D-glucopyranoside is reported for the first time.