We report on the synthesis of an active component, 2-(4-hydroxyphenyl)ethyl 3,4,5-trihydroxybenzoate (HETB), from Rhodiola crenulata. Subsequent analysis revealed that HETB exhibits α-glucosidase inhibitory activities on maltase and sucrase, with potency exceeding that of the known α-glucosidase inhibitors (voglibose and acarbose). An inhibition kinetics study revealed that HETB, acarbose, and voglibose bind to maltase and sucrase, and HETB was shown to be a strong competitive inhibitor of maltase and sucrase. In a molecular docking study based on the crystal structure of α-glucosidase from Saccharomyces cerevisiae, we revealed the HETB binding in the active site of maltase via hydrogen-bond interactions with five amino acid residues: Ser 240, Asp 242, Glu 277, Arg 315, and Asn 350. For HETB docked to the sucrase active site, seven hydrogen bonds (with Asn 114, Glu 148, Gln 201, Asn 228, Gln 381, Ile 383, and Ser 412) were shown.

中文翻译：

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3,4,5-三羟基苯甲酸2-（4-羟苯基）乙酯的合成及其对蔗糖酶和马耳他酶的抑制作用

我们对活性成分的合成中，2-（4-羟基苯基）乙基3,4,5-三羟基苯甲酸（被HetB）报道，从大花红景天。随后的分析显示，HETB对麦芽糖酶和蔗糖酶表现出α-葡萄糖苷酶抑制活性，其效力超过已知的α-葡萄糖苷酶抑制剂（伏格列波糖和阿卡波糖）。抑制动力学研究表明，HETB，阿卡波糖和伏格列波糖与麦芽糖酶和蔗糖酶结合，并且HETB被证明是麦芽糖酶和蔗糖酶的强竞争性抑制剂。在基于酿酒酵母α-葡萄糖苷酶晶体结构的分子对接研究中，我们通过与五个氨基酸残基的氢键相互作用揭示了麦芽糖酶活性位点上的HETB结合：Ser 240，Asp 242，Glu 277，Arg 315和Asn350。对于停靠在蔗糖酶活性位点上的HETB，七个氢所示的键（具有Asn 114，Glu 148，Gln 201，Asn 228，Gln 381，Ile 383和Ser 412）。