本文研究了柚皮素与α-淀粉酶的相互作用。柚皮素与α-淀粉酶反应形成复合物，从而对α-淀粉酶的催化活性、荧光特性以及柚皮素的抗氧化活性产生相应的影响。采用酶动力学方法和荧光光谱法研究了柚皮素对α-淀粉酶的抑制作用。在pH 6.8、37 ℃条件下反应20 min，柚皮素（1 mg/mL，0.05 mL）对α-淀粉酶（0.33 U/mL, 0.2 mL）催化活性的抑制率达到36.6 %。该抑制作用是以非竞争性方式进行。柚皮素对α-淀粉酶的内源性荧光产生有规律的猝灭作用，其方式以静态猝灭为主。二者主要通过疏水作用力发生结合反应形成复合物，有1个结合位点，表观结合常数约105 L/mol。另一方面，由于与α-淀粉酶发生复合反应，柚皮素的还原力和抗亚油酸氧化的活性也有一定程度的降低，而可能导致其生物活性发生改变。

The complex formed by naringenin and α-amylase resulted in the decreased antioxidant activity of naringenin and catalytic activity of enzyme, as well as efficient quenching of the intrinsic fluorescence of α-amylase. The inhibitory effect of naringenin on α-amylase was studied by enzymatic kinetics and fluorescence spectroscopy. α-Amylase (0.33 U/mL, 0.2 mL) was treated by naringenin (1 mg/mL, 0.05 mL) under pH 6.8, 37 ℃ for 20 min, the inhibition rate reached 36.6 %. The mechanism of inhibition effect was noncompetitive inhibition. The regular quenching of intrinsic fluorescence of α-amylase was induced by naringenin as a quencher in physiological condition, and the majority was static quenching. Naringenin binded with α-amylase to form a new complex was using hydrophobic interaction. An α-amylase molecule provided one binding site for a naringenin molecule, with the apparent binding constant Kb around 105 L?mol-1. The total antioxidant activity in linoleic acid emulsion and reducing power of naringenin were also inhibited by α-amylase, which might lead to the change of biological activity of naringenin.

国家自然科学基金项目(21002034)；华南理工大学中央高校基本科研业务费项目（2013ZZ0080）；华南理工大学广东省绿色精细化学产品工程技术研究中心研究基金资助课题