School of Pharmacy and Medical Technology, Putian University, Fujian, China.
Key Laboratory of Pharmaceutical Analysis and Laboratory Medicine (Putian University), Fujian Province University, Fujian, China.
Curr Pharm Biotechnol. 2024;25(4):477-487. doi: 10.2174/1389201024666230621141014.
Background: Cinnamic acid and its derivatives have gained significant attention in recent medicinal research due to their broad spectrum of pharmacological properties. However, the effects of these compounds on xanthine oxidase (XO) have not been systematically investigated, and the inhibitory mechanism remains unclear.
Objectives: The objective of this study was to screen 18 compounds and identify the XO inhibitor with the strongest inhibitory effect. Furthermore, we aimed to study the inhibitory mechanism of the identified compound.
Methods: The effects of the inhibitors on XO were evaluated using kinetic analysis, docking simulations, and study. Among the compounds tested, 4-NA was discovered as the first XO inhibitor and exhibited the most potent inhibitory effects, with an IC value of 23.02 ± 0.12 μmol/L. The presence of the nitro group in 4-NA was found to be essential for enhancing XO inhibition. The kinetic study revealed that 4-NA inhibited XO in a reversible and noncompetitive manner. Moreover, fluorescence spectra analysis demonstrated that 4-NA could spontaneously form complexes with XO, referred to as 4-NA-XO complexes, with the negative values of △H and ΔS.
Results: This suggests that hydrogen bonds and van der Waals forces play crucial roles in the binding process. Molecular docking studies further supported the kinetic analysis and provided insight into the optimal binding conformation, indicating that 4-NA is located at the bottom outside the catalytic center through the formation of three hydrogen bonds. Furthermore, animal studies confirmed that the inhibitory effects of 4-NA on XO resulted in a significant reduction of serum uric acid level in hyperuricemia mice.
Conclusion: This work elucidates the mechanism of 4-NA inhibiting XO, paving the way for the development of new XO inhibitors.
.背景：肉桂酸及其衍生物因其广泛的药理特性在最近的医学研究中受到了极大的关注。然而，这些化合物对黄嘌呤氧化酶（XO）的影响尚未得到系统研究，其抑制机制尚不清楚。
目的：本研究旨在筛选 18 种化合物，鉴定出对 XO 抑制作用最强的化合物。此外，我们旨在研究鉴定出的化合物的抑制机制。
方法：采用动力学分析、对接模拟和实验研究评估抑制剂对 XO 的影响。在所测试的化合物中，发现 4-NA 是第一个 XO 抑制剂，具有最强的抑制作用，IC 值为 23.02±0.12 μmol/L。4-NA 中硝基的存在被发现对增强 XO 抑制至关重要。动力学研究表明，4-NA 以可逆和非竞争性方式抑制 XO。此外，荧光光谱分析表明，4-NA 可以与 XO 自发形成复合物，称为 4-NA-XO 复合物，其△H 和△S 为负值。
结果：这表明氢键和范德华力在结合过程中起着关键作用。分子对接研究进一步支持了动力学分析，并提供了最佳结合构象的深入了解，表明 4-NA 通过形成三个氢键位于催化中心的底部外部。此外，动物研究证实，4-NA 对 XO 的抑制作用导致高尿酸血症小鼠血清尿酸水平显著降低。
结论：本研究阐明了 4-NA 抑制 XO 的机制，为开发新的 XO 抑制剂铺平了道路。
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