Abstract：
Bakuchiol is gaining major interest for treatments against skin photoaging. The kinetics of mushroom tyrosinase inhibition by bakuchiol, by real-time oxygen sensing and UV-vis monitoring (475 nm), showed competitive inhibition with average Ki constant (µM, 30 °C, pH 6.8) of 6.71 ± 1.23 and 1.15 ± 0.34 for monophenolase and diphenolase reactions respectively, with respective IC50 37.22 ± 5.18 and 6.91 ± 0.96 ∼ at 1 mM substrate, compared to kojic acid IC50 34.02 ± 5.51 and 16.86 ± 3.28 μM. Fluorescence quenching showed a single binding mode with formation constant Ka 1.02 × 106 M-1. The antioxidant activity was studied by inhibited autoxidation of styrene and cumene (PhCl, 30 °C) affording inhibition constant kinh = 18.1 ± 6.6 (104M-1s-1, 30 °C) and of MeLin in Triton™ X-100 micelles giving kinh = 0.16 ± 0.03 (104M-1s-1, 37 °C). Stoichiometric factor was 1.9 ± 0.1. ReqEPR spectroscopy afforded the BDE(OH) as 81.7 ± 0.1 kcal/mol. Bakuchiol is a potent tyrosinase inhibitor with good antioxidant activity having major potential as natural food preservative against oxidation and food-browning.
摘要：
Bakuchiol正在获得针对皮肤光老化的治疗的主要兴趣。bakuchiol抑制蘑菇酪氨酸酶的动力学，通过实时氧气传感和紫外可见监测(475nm)，显示竞争性抑制，平均Ki常数（µM，30°C,单酚酶和二酚酶反应的pH6.8）分别为6.71±1.23和1.15±0.34，在1mM底物下，IC50分别为37.22±5.18和6.91±0.96，与曲酸IC5034.02±5.51和16.86±3.28μM相比。荧光猝灭显示单一结合模式，形成常数Ka1.02×106M-1。通过抑制苯乙烯和异丙苯（PhCl，30°C）提供抑制常数kinh=18.1±6.6（104M-1s-1，30°C），并且在Triton™X-100胶束中的MeLin提供kinh=0.16±0.03（104M-1s-1，37°C）。化学计量系数为1.9±0.1。ReqEPR光谱得到的BDE(OH)为81.7±0.1kcal/mol。Bakuchiol是一种有效的酪氨酸酶抑制剂，具有良好的抗氧化活性，具有作为天然食品防腐剂抵抗氧化和食品褐变的主要潜力。
