Li Lijun, Cai Yuchen, Sun Xu, Du Xiping, Jiang Zedong, Ni Hui, Yang Yuanfan, Chen Feng
College of Food and Biological Engineering Jimei University Xiamen China.
Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering Xiamen China.
Food Sci Nutr. 2020 Dec 11;9(1):389-400. doi: 10.1002/fsn3.2004. eCollection 2021 Jan.
A tyrosinase inhibitor was separated from camellia pollen with the aid of solvent fraction, macroporous adsorptive resin chromatography, and high-speed countercurrent chromatography. The inhibitor was identified to be -coumaric acid ethyl ester (-CAEE) by nuclear magnetic resonance and mass spectrum. Its inhibitory activity (IC = 4.89 μg/ml) was about 10-fold stronger than arbutin (IC = 51.54 μg/ml). The -CAEE inhibited tyrosinase in a noncompetitive model with the and of 1.83 μg/ml and 0.52 mM, respectively. Fluorescence spectroscopy analysis showed the -CAEE quenched an intrinsic fluorescence tyrosinase. UV-Vis spectroscopy analysis showed the -CAEE did not interact with copper ions of the enzyme. Docking simulation implied the CAEE induced a conformational change in the catalytic region and thus changed binding forces of L-tyrosine. Our findings suggest that -CAEE plays an important role in inhibiting tyrosinase and provides a reference for developing pharmaceutical, cosmetic, and fruit preservation products using pollen.
通过溶剂分级、大孔吸附树脂色谱和高速逆流色谱法，从茶花花粉中分离出一种酪氨酸酶抑制剂。通过核磁共振和质谱鉴定该抑制剂为对香豆酸乙酯（-CAEE）。其抑制活性（IC = 4.89μg/ml）比熊果苷（IC = 51.54μg/ml）强约10倍。-CAEE在非竞争性模型中抑制酪氨酸酶，其Ki和IC50分别为1.83μg/ml和0.52mM。荧光光谱分析表明-CAEE淬灭了酪氨酸酶的内在荧光。紫外-可见光谱分析表明-CAEE不与酶的铜离子相互作用。对接模拟表明CAEE诱导了催化区域的构象变化，从而改变了L-酪氨酸的结合力。我们的研究结果表明-CAEE在抑制酪氨酸酶方面起着重要作用，并为开发使用花粉的医药、化妆品和水果保鲜产品提供了参考。
