Shanghai Engineering Research Center of Food Microbiology, School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, China.
Yunnan Provincial Key Laboratory of Applied Technology for Special Forest Fruits, Yunnan Maoduoli Group Food Co., Ltd., Yuxi, China.
J Sci Food Agric. 2024 Dec;104(15):9719-9728. doi: 10.1002/jsfa.13796. Epub 2024 Aug 12.
Phyllanthus emblica Linn. (PE) is rich in polyphenols, which can be categorized into free and bound phenolics (PEFP and PEBP). This study evaluated the inhibitory effect of PEFB and PEBP on α-amylase for the first time. The mechanism of the inhibition effect of PEFP and PEBP on α-amylase was investigated by enzyme inhibition kinetics, multispectral analysis, thermodynamics, and molecular docking.
Free and bound phenolics inhibited α-amylase activity effectively in a mixed type of inhibition. Fluorescence quenching and thermodynamic analyses showed that the binding of PEFP and PEBP to α-amylase occurred through a static quenching process (K = 6.94 × 10¹² and 5.74 × 10¹² L mol s), which was accompanied by a redshift (λem from 343 to 347 nm), leading to a change in the microenvironment. This process was found to be a spontaneous exothermic reaction (ΔG < 0). Circular dichroism (CD) analysis confirms that the secondary structure of α-amylase was altered, in particular a decrease in α-helixes and an increase in random coils. Molecular docking studies showed that PEFP and PEBP interacted with α-amylase through hydrogen bonding and hydrophobic interactions.
The present study provides valuable insights into the mechanism of action of PEFP and PEBP on α-amylase, which will provide a theoretical basis for their possible use as novel natural α-amylase inhibitors. © 2024 Society of Chemical Industry.
余甘子（PE）富含多酚，可分为游离和结合酚（PEFP 和 PEBP）。本研究首次评估了 PEFB 和 PEBP 对α-淀粉酶的抑制作用。通过酶抑制动力学、多光谱分析、热力学和分子对接研究了 PEFP 和 PEBP 对α-淀粉酶抑制作用的机制。
游离和结合酚以混合抑制类型有效抑制α-淀粉酶活性。荧光猝灭和热力学分析表明，PEFP 和 PEBP 与α-淀粉酶的结合通过静态猝灭过程发生（K = 6.94 × 10¹²和 5.74 × 10¹² L mol s），伴随着红移（λem 从 343 到 347nm），导致微环境发生变化。该过程是自发的放热反应（ΔG < 0）。圆二色性（CD）分析证实α-淀粉酶的二级结构发生了变化，特别是α-螺旋减少，随机卷曲增加。分子对接研究表明，PEFP 和 PEBP 通过氢键和疏水相互作用与α-淀粉酶相互作用。
本研究为 PEFP 和 PEBP 对α-淀粉酶作用机制提供了有价值的见解，可为其作为新型天然α-淀粉酶抑制剂的可能用途提供理论依据。© 2024 化学工业协会。
