| Purified the anti-hyperuricemic components from Guanglin No.9 eucalyptus leaves by screening xanthine oxidase inhibitory activity in vitro and identified their structures. The inhibitory effects of extracts from eucalyptus leaveson xanthine oxidase (XOD) were measured by HPLC analysis. The mobile phases consisted of methanol-K2HPO4 buffer liquid (50mmol/L, pH 7.5, 5：95) and detection wavelength was 290 nm. The inhibitory effects on XOD of different extracts from eucalyptus leaves were determined to confirm the optimal extraction conditions, and used Diaion HP-20 macroporousresin, ODS and preparation HPLC to purify the extracts from eucalyptus leaves. The most active compounds, which were ellagic acid, Quercetin-3-O-glucuronide and Pentagalloyl glucose, were isolated with IC50s 22.51, 32.96, 31.75 μg/mL, respectively. The inhibitory types and Kis of these three compounds were also studied through kinetics research, as the Ki of ellagic acid was minimum, 1.048 μg/mL, so the inhibitory effect on XOD of the ellagic acid was the best among these three compounds. |
