Qin et al. demonstrated for the first time that the norathyriol 3-benzyloxy derivative J99745 (Figure 22) presented an in vitro XO inhibition, with a determined IC50 value of 3.297 μM. Experiments involving hyperuricemia mice showed that J99745 at doses of 10 and 30 mg/kg significantly reduced serum urate levels, enhanced UA excretion, and provided higher nephroprotective effects than allopurinol. The gene discussed is XDH; the disease is hyperuricemia.