Department of Food and Life Science, Pukyong National University, Busan 48513, Korea.
Department of Food Science and Human Nutrition, Chonbuk National University, Jeonju 54896, Korea.
Molecules. 2018 Jun 11;23(6):1413. doi: 10.3390/molecules23061413.
Kuwanon G (KG) and benzofuran flavonoids such as mulberrofuran G (MG) and albanol B (AB) isolated from sp. are reported to exhibit anti-Alzheimer’s disease, anti-inflammatory, fungicidal, anti-cancer, anti-bacterial, and anti-tyrosinase properties. We investigated the inhibition of mono- and diphenolase activity of mushroom tyrosinase by KG, MG, and AB. KG and MG displayed acceptable inhibition activity compared to kojic acid. AB did not show any activity up to 350 µM. MG displayed six-fold higher inhibition of -tyrosine oxidation (IC = 6.35 ± 0.45 µM) compared to kojic acid (IC = 36.0 µM). Kinetic studies revealed that KG and MG inhibited monophenolase activity of tyrosinase in a competitive manner. Docking simulations of KG and MG demonstrated favorable binding energies with amino acid residues of the active sites of tyrosinase. Our investigation of the structure-activity relationship of the fused benzofuran flavonoids (MG vs. AB) implicated the methyl cyclohexene ring moiety in tyrosinase inhibition. The enzyme substrate and relative structural analyses demonstrated that KG and MG from sp. could be useful natural tyrosinase inhibitors in foods or cosmetics.
从 中分离得到的库瓦酮 G（KG）和苯并呋喃类黄酮，如桑根呋喃 G（MG）和阿尔巴诺醇 B（AB），据报道具有抗老年痴呆症、抗炎、杀菌、抗癌、抗菌和抗酪氨酸酶的特性。我们研究了 KG、MG 和 AB 对蘑菇酪氨酸酶单酚酶和二酚酶活性的抑制作用。与曲酸相比，KG 和 MG 表现出可接受的抑制活性。AB 即使在 350 µM 时也没有显示出任何活性。MG 对 -酪氨酸氧化的抑制活性是曲酸的六倍（IC = 6.35 ± 0.45 µM）（IC = 36.0 µM）。动力学研究表明，KG 和 MG 以竞争性方式抑制酪氨酸酶的单酚酶活性。KG 和 MG 的对接模拟表明，它们与酪氨酸酶活性部位的氨基酸残基具有良好的结合能。我们对融合苯并呋喃类黄酮（MG 与 AB）的构效关系的研究表明，酪氨酸酶抑制中环己烯基甲基部分的存在。酶底物和相对结构分析表明， 中的 KG 和 MG 可能是食品或化妆品中有用的天然酪氨酸酶抑制剂。
