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目的:采用酶促反应动力学方法研究补骨脂酚对酪氨酸单酚酶和二酚酶活性的影响,并考察补骨脂酚对酪氨酸酶的作用机制及动力学参数。方法:在p H 6.8的磷酸盐缓冲体系中,分别以L-酪氨酸和左旋多巴为底物,37℃反应后在475 nm处测定吸光度,研究补骨脂酚对酪氨酸酶催化反应进程和酶活性抑制的影响,计算抑制动力学参数。结果:补骨脂酚对酪氨酸单酚酶和二酚酶均有抑制作用,半抑制浓度分别为1.49,0.41 mmol·L~(-1),其中对酪氨酸二酚酶的抑制作用表现为可逆抑制,其抑制作用表现为竞争性抑制,抑制常数0.955 mmol·L~(-1)。结论:在低浓度范围内,补骨脂酚对酪氨酸酶的抑制作用较熊果苷更明显,具有开发成天然酪氨酸酶抑制剂的潜力。
OBJECTIVE: To study the effect of bakuchiol on the tyrosine monophenol and diphenolase activities by enzymatic reaction kinetics and investigate the mechanism of action and kinetic parameters of bakuchiol on tyrosinase. Methods: Absorbance was measured at 475 nm after reaction at 37 ℃ with L-tyrosine and levodopa in phosphate buffer system of p H 6.8. The effects of bakuchiol on tyrosinase The reaction progress and the inhibition of enzyme activity were calculated and the inhibition kinetic parameters were calculated. Results: Bakuchiol inhibited the tyrosine monophenol and diphenolase at half-inhibitory concentrations of 1.49 and 0.41 mmol·L -1, respectively. The inhibitory effect on tyrosine diphenols It showed reversible inhibition. The inhibitory effect was competitive inhibition with an inhibition constant of 0.955 mmol·L -1. CONCLUSION: In the low concentration range, the inhibitory effect of bakuchiol on tyrosinase is more obvious than that of arbutin, which has the potential to develop into a natural tyrosinase inhibitor.