College of Food Science and Engineering, Northwest A&F University, Yangling, China.
College of Food Science and Engineering, Northwest A&F University, Yangling, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2023 Jan 15;285:121797. doi: 10.1016/j.saa.2022.121797. Epub 2022 Aug 28.
Inhibiting the activity of α-amylase has been considered an effective strategy to manage hyperglycemia. Hyperoside and quercetin are the main natural flavonoids in various plants, and the inhibition mechanism on α-amylase remains unclear. In this study, the structure-activity relationships between hyperoside/quercetin and α-amylase were evaluated by enzyme kinetic analysis, multi-spectroscopic techniques, and molecular docking analysis. Results showed that hyperoside and quercetin exhibited significant α-amylase inhibitory activities with IC values of 0.491 and 0.325 mg/mL, respectively. The α-amylase activity decreased in the presence of hyperoside and quercetin in a competitive and noncompetitive manner, respectively. UV-vis spectra suggested that the aromatic amino acid residues (Trp and Tyr) microenvironment of α-amylase changed in the presence of these two flavonoids. FTIR and CD spectra showed the vibrations of the amide bands and the secondary structure content changes. The fluorescence quenching mechanism of α-amylase by hyperoside and quercetin belonged to the static quenching type. Finally, molecular docking intuitively showed that hyperoside/quercetin formed hydrogen bonds with the key active site residues (Asp197, Glu233, and Asp300) in α-amylase. MD simulation indicated hyperoside/quercetin-α-amylase docked complexes had good stability. Taken together, this research provides new sights to developing potent drugs or functional foods with hyperoside and quercetin, offering new avenues for hyperglycemia treatment.
抑制α-淀粉酶的活性被认为是控制高血糖的有效策略。桃叶珊瑚苷和槲皮素是各种植物中主要的天然类黄酮，其对α-淀粉酶的抑制机制尚不清楚。在这项研究中，通过酶动力学分析、多光谱技术和分子对接分析评估了桃叶珊瑚苷/槲皮素与α-淀粉酶之间的构效关系。结果表明，桃叶珊瑚苷和槲皮素有显著的α-淀粉酶抑制活性，IC值分别为 0.491 和 0.325 mg/mL。在桃叶珊瑚苷和槲皮素的存在下，α-淀粉酶活性以竞争和非竞争方式降低。紫外可见光谱表明，在这两种类黄酮存在下，α-淀粉酶的芳香族氨基酸残基（色氨酸和酪氨酸）微环境发生了变化。傅里叶变换红外光谱和圆二色光谱显示了酰胺带的振动和二级结构含量的变化。桃叶珊瑚苷和槲皮素对α-淀粉酶的荧光猝灭机制属于静态猝灭类型。最后，分子对接直观地表明，桃叶珊瑚苷/槲皮素与α-淀粉酶的关键活性位点残基（Asp197、Glu233 和 Asp300）形成氢键。MD 模拟表明，桃叶珊瑚苷/槲皮素-α-淀粉酶对接复合物具有良好的稳定性。总之，这项研究为开发具有桃叶珊瑚苷和槲皮素的有效药物或功能性食品提供了新的思路，为高血糖的治疗提供了新的途径。
