Sericultural & Agri-Food Research Institute Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs/Guangdong Key Laboratory of Agricultural Products Processing, Guangzhou 510610, PR China.
Department of Horticulture, Guangdong Eco-Engineering Polytechnic, Guangzhou 510520, PR China.
Food Chem. 2022 Mar 15;372:131306. doi: 10.1016/j.foodchem.2021.131306. Epub 2021 Oct 5.
Brown rice bound phenolics extracts (BRBPE) have been reported to possess α-glucosidase inhibitory effects, the specific enzyme inhibitors involved in this process were unknown. Here, α-glucosidase inhibitors in BRBPE were screened using bioaffinity ultrafiltration methods, and seven phenolic compounds - three monomers (p-coumaric acid, ferulic acid and methyl ferulate), three dimers (8-5', 5-5' and 8-O-4' diferulic acid) and a trimer (5-5'/8-O-4″ dehydrotriferulic acid) were identified as exact inhibitors, among which 5-5'/8-O-4″ dehydrotriferulic acid and 5-5'diferulic acid exhibited the best inhibitory activity. Enzyme kinetic analysis suggested that the inhibitory mechanism of these seven inhibitors including competitive, noncompetitive, uncompetitive and mixed manner. Molecular docking analysis revealed that the seven inhibitors bind with α-glucosidase mainly by hydrogen bonding interaction, hydrophobic force and ionic bond. Molecular dynamics simulation further explored the structure and molecular property of phenolic-glucosidase complex. This work provided a deep insight into brown rice bound phenolics acting as potent α-glucosidase inhibitors.
糙米结合型酚提取物（BRBPE）已被报道具有α-葡萄糖苷酶抑制作用，但涉及该过程的特定酶抑制剂尚不清楚。在这里，使用生物亲和超滤方法筛选 BRBPE 中的α-葡萄糖苷酶抑制剂，鉴定出 7 种酚类化合物-3 种单体（对香豆酸、阿魏酸和甲基阿魏酸）、3 种二聚体（8-5'、5-5'和 8-O-4'二阿魏酸）和 1 种三聚体（5-5'/8-O-4″脱氢三阿魏酸）为确切的抑制剂，其中 5-5'/8-O-4″脱氢三阿魏酸和 5-5'二阿魏酸表现出最好的抑制活性。酶动力学分析表明，这 7 种抑制剂的抑制机制包括竞争性、非竞争性、反竞争性和混合性。分子对接分析表明，这 7 种抑制剂主要通过氢键相互作用、疏水相互作用和离子键与α-葡萄糖苷酶结合。分子动力学模拟进一步探讨了酚-葡萄糖苷酶复合物的结构和分子特性。这项工作深入了解了糙米结合型酚作为有效的α-葡萄糖苷酶抑制剂的作用机制。
