CHEMBL5733485

XO (Xanthine Oxidase) Inhibition Activity Assay: The compound was diluted 2.5 fold with a buffer of 50 mM KH2PO4 to give a series of concentrations from 2000 nM to 0.524 nM. Then the diluted solution was added to a 384 well plate at 30 μL/well, and then to each well was added 30 μL of 21 mU/mL xanthine oxidase. The resulting solution was centrifuged at 3000 rpm for 1 min, shook and incubated at room temperature for 10 min, then to each well was added 30 μL of 600 μM substrate (xanthine); at the same time, the well was treated with the buffer (no compound, added the same concentration of enzyme and substrate) and a negative control well (no compound and enzyme, added the same concentration of substrate) were set up. After being incubated at room temperature for 5 min, absorbance at 290 nm was read by using PHERAstar FS microplate reader. The inhibition rate of the compound against xanthine oxidase (XO) was calculated by the following formula, and IC50 values were calculated by using GraphPad Prism 5.