The enzyme tyrosinase plays a key role in the early stages of melanin biosynthesis. This study evaluated the inhibitory activity of anthocyanidin (1) and anthocyanins (2–6) on the catalytic reaction. Of the six derivatives examined, 1–3 showed inhibitory activity with IC₅₀ values of 3.7 ± 0.1, 10.3 ± 1.0, and 41.3 ± 3.2 μM, respectively. Based on enzyme kinetics, 1–3 were confirmed to be competitive inhibitors with K_i values of 2.8, 9.0, and 51.9 μM, respectively. Molecular docking analysis revealed the formation of a binary encounter complex between 1–3 and the tyrosinase catalytic site. Luteolinidin (1) and petunidin 3-O-glucoside (2) may serve as tyrosinase inhibitors to block melanin production.

中文翻译：

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Luteolinidin 和 Petunidin 3-O-Glucoside：酪氨酸酶的竞争性抑制剂

酪氨酸酶在黑色素生物合成的早期阶段起关键作用。本研究评价了花青素（ 1）和花青素（2-6）对催化反应的抑制活性。在所检查的六种衍生物中，1-3种显示出抑制活性，IC ₅₀值分别为 3.7 ± 0.1、10.3 ± 1.0 和 41.3 ± 3.2 μM。基于酶动力学，1-3被证实是竞争性抑制剂，K _{i值分别为}2.8、9.0和 51.9 μM。分子对接分析揭示了在1-3之间形成二元遭遇复合物和酪氨酸酶催化位点。Luteolinidin ( 1 ) 和 Petunidin 3- O -glucoside ( 2 ) 可以作为酪氨酸酶抑制剂来阻断黑色素的产生。