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 p‐coumaric acid ethyl ester (p‐CAEE) by nuclear magnetic resonance and mass spectrum. Its inhibitory activity (IC₅₀ = 4.89 μg/ml) was about 10‐fold stronger than arbutin (IC₅₀ = 51.54 μg/ml). The p‐CAEE inhibited tyrosinase in a noncompetitive model with the K_I and K_m of 1.83 μg/ml and 0.52 mM, respectively. Fluorescence spectroscopy analysis showed the p‐CAEE quenched an intrinsic fluorescence tyrosinase. UV‐Vis spectroscopy analysis showed the p‐CAEE did not interact with copper ions of the enzyme. Docking simulation implied the p‐CAEE induced a conformational change in the catalytic region and thus changed binding forces of L‐tyrosine. Our findings suggest that p‐CAEE plays an important role in inhibiting tyrosinase and provides a reference for developing pharmaceutical, cosmetic, and fruit preservation products using pollen.

中文翻译：

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从山茶花粉中鉴定出对香豆酸乙酯抑制酪氨酸酶

通过溶剂馏分，大孔吸附树脂色谱法和高速逆流色谱法从山茶花粉中分离出酪氨酸酶抑制剂。通过核磁共振和质谱鉴定该抑制剂为对香豆酸乙酯（p- CAEE）。它的抑制活性（IC ₅₀  = 4.89μg/ ml）比熊果苷（IC ₅₀  = 51.54μg/ ml）强约10倍。所述p -CAEE抑制酪氨酸酶与非竞争性模型ķ_我和ķ_米1.83微克/毫升和0.52毫米，分别的。荧光光谱研究表明p‐CAEE淬灭了固有的荧光酪氨酸酶。紫外-可见光谱分析表明，p- CAEE与酶的铜离子没有相互作用。对接模拟表明，p- CAEE在催化区域引起构象变化，从而改变了L-酪氨酸的结合力。我们的发现表明，p- CAEE在抑制酪氨酸酶中起着重要作用，并为开发使用花粉的药物，化妆品和水果保鲜产品提供了参考。