Key Laboratory of Structure-Based Drugs Design & Discovery of Ministry of Education, School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, 103 Culture Road, Shenhe District, Shenyang, 110016, China.
Key Laboratory of Structure-Based Drugs Design & Discovery of Ministry of Education, School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, 103 Culture Road, Shenhe District, Shenyang, 110016, China.
Eur J Med Chem. 2019 Nov 1;181:111559. doi: 10.1016/j.ejmech.2019.07.062. Epub 2019 Jul 24.
Xanthine oxidase is an important target for the treatment of hyperuricemia, gout and other related diseases. Analysis of the high-resolution structure of xanthine oxidase with febuxostat identified the existence of a subpocket formed by the residues Leu648, Asn768, Lys771, Leu1014 and Pro1076. In this study, we designed and synthesized a series of 2-[4-alkoxy-3-(1H-tetrazol-1-yl) phenyl]-6-oxo-1,6-dihydropyrimidine-5-carboxylic acid derivatives (8a-8z) with a tetrazole group targeting this subpocket of the xanthine oxidase active site, and they were further evaluated for their inhibitory potency against xanthine oxidase in vitro. The results showed that all the tested compounds (8a-8z) exhibited an apparent xanthine oxidase inhibitory potency, with IC values ranging from 0.0288 μM to 0.629 μM. Among them, compound 8u emerged as the most potent xanthine oxidase inhibitor, with an IC value of 0.0288 μM, which was comparable to febuxostat (IC = 0.0236 μM). The structure-activity relationship results revealed that the hydrophobic group at the 4'-position was indispensable for the inhibitory potency in vitro against xanthine oxidase. A Lineweaver-Burk plot revealed that the representative compound 8u acted as a mixed-type inhibitor for xanthine oxidase. Furthermore, molecular modeling studies were performed to gain insights into the binding mode of 8u with xanthine oxidase and suggested that the tetrazole group of the phenyl unit was accommodated in the subpocket, as expected. Moreover, a potassium oxonate-induced hyperuricemia model in rats was chosen to further confirm the hypouricemic effect of compound 8u, and the result demonstrated that compound 8u could effectively reduce serum uric acid levels at an oral dose of 5 mg/kg. In addition, acute oral toxicity study in mice indicated that compound 8u was nontoxic and tolerated at a dose up to 2000 mg/kg. Thus, compound 8u could be a potential and efficacious agent in treatment of hyperuricemia with low toxicity.
黄嘌呤氧化酶是治疗高尿酸血症、痛风和其他相关疾病的重要靶点。利用非布司他分析黄嘌呤氧化酶的高分辨率结构，确定了由残基 Leu648、Asn768、Lys771、Leu1014 和 Pro1076 形成的亚口袋的存在。在这项研究中，我们设计并合成了一系列具有 1H-四唑-1-基的 2-[4-烷氧基-3-(1H-四唑-1-基)苯基]-6-氧代-1,6-二氢嘧啶-5-羧酸衍生物（8a-8z），这些化合物靶向黄嘌呤氧化酶活性部位的这个亚口袋，并进一步评估了它们在体外对黄嘌呤氧化酶的抑制活性。结果表明，所有测试的化合物（8a-8z）均表现出明显的黄嘌呤氧化酶抑制活性，IC 值范围为 0.0288 μM 至 0.629 μM。其中，化合物 8u 表现出最强的黄嘌呤氧化酶抑制活性，IC 值为 0.0288 μM，与非布司他（IC=0.0236 μM）相当。构效关系结果表明，4′-位的疏水性基团对于体外抑制黄嘌呤氧化酶的活性是必不可少的。Lineweaver-Burk 作图表明，代表性化合物 8u 对黄嘌呤氧化酶表现为混合型抑制剂。此外，还进行了分子建模研究，以深入了解 8u 与黄嘌呤氧化酶的结合模式，并表明苯环单元的四唑基团被容纳在亚口袋中，这与预期一致。此外，选择氧嗪酸钾诱导的大鼠高尿酸血症模型进一步证实了化合物 8u 的降尿酸作用，结果表明，化合物 8u 可在 5mg/kg 口服剂量下有效降低血清尿酸水平。此外，在小鼠中的急性口服毒性研究表明，化合物 8u 在高达 2000mg/kg 的剂量下无毒性且可耐受。因此，化合物 8u 可能是一种具有低毒性的治疗高尿酸血症的有效候选药物。
