Design, Synthesis, And Screening Of The Anti-gout Compounds Based On The Three-Dimensional Structure Of Xanthine Oxidase

The xanthine oxidoreductase (XOR) is generally recognized as a key enzyme in purine catabolism, which catalyze the hydroxylation of hypoxanthine and xanthine, the two last steps in the formation of urate. The enzyme increases the levels of plasma uric acid and causes gout. It has been reported that XOR is a target of drugs against gout and hyperuricemia. In present, Allopurinol and Oxipurinol are the only drug which have been approved for the treatment of gout and hyperuricemia. But adverse side effects have limited their use such as interstitial nephritis, renal dysfunction, hepatic toxicity, vasculitis and hypersensitivity syndrome. Furthermore, Allopurinol is limited its use because of the excretion which is involved with kidneys.It highlights an urgent necessity for the development of novel xanthine oxidase inhibitors.Xanthine oxidoreductase (XOR) is a important class of molybdenum-containing iron– sulfur flavoproteins. The active form of the enzyme is a homodimer of molecular, with each of the monomers mass 147 kDa and appears catalysis effect dependently. Each subunit contains one molybdopterin group, two non-identical [2Fe–2S] centers, and one flavin adenine dinucleotide (FAD) cofactor. Xanthine oxidoreductase (XOR) has been widely distributed in the tissues of mammalian. It appears high concentrations in liver and intestinal. It has been reported that a novel non-purine selective inhibitor of xanthine oxidase can block both xanthine dehydrogenase and xanthine oxidase appearing better activity than Allopurinol. The XOR inhibitors is metabolized through liver avoiding adverse effect caused by Allopurinol which is excreted by kidney.Febuxostat(TEI-6720,TMX-67), a novel non-purine selective inhibitor of xanthine oxidase, developed by Teijin Ltd. Japan, was able to inhibit both xanthine dehydrogenase and xanthine oxidase with significant inhibitory activity. According to the completed phase III clinical trial of Febuxostat, the result has elucidated that Febuxostat is prior to Allopurinol whatever on the therapeutic effect, safety of dose or side effects. Febuxostat also can be used for the patients who are not tolerant to Allopurinol.In our research work, we chose Febuxostat as our lead compound. According to patents, development progress of anti-gout drug, known quantitative structure-activity relationship, the length and volume of drug molecular and the relationship between drug molecular and the amino acids in activity site of xanthine oxidoreductase, we build a virtual compounds library by using traditional and computer-aided drug designing methods. By molecular docking, a series compounds have high scores. Based on the docking result, 38 compounds have synthesized. All compounds were characterized by 1H-NMR and MS.In vitro ,we screened the inhibitory activity of 38 compounds on xanthine oxidase, three compounds of them appeared better inhibitory activity on xanthine oxidase .The IC50 value of compounds WJ080111 and WJ080328 is 28.54×10-6 mol/L and 16.28×10-6 mol/L, respectively.According to the initial XOI activity assay results, We discussed the effect of substituents on the position 1 and the positon 3 Aromatic ring of 1,2,4-triazole ring on biological activity which might be very useful for our further research work. We also selected three compounds for docking comparing with Febuxostat which have better biological activity than others.