藏荆芥提取物对酪氨酸酶活性及其动力学研究

以L-酪氨酸和L-多巴为底物,采用酶促反应动力学方法研究藏荆芥提取物对酪氨酸单酚酶和二酚酶活性的影响以及抑制动力学。结果表明,藏荆芥提取物对酪氨酸单酚酶和二酚酶均有抑制作用,单酚酶和二酚酶活力下降50%的藏荆芥提取物质量浓度(IC₅₀)分别为0.1388和0.5332g/L。藏荆芥提取物对酪氨酸二酚酶的抑制作用属于可逆过程,Lineweaver-Burk图显示其作用类型表现为竞争性抑制,抑制常数为504.846mg/L。藏荆芥提取物对酪氨酸酶有明显的抑制作用,具有开发成天然酪氨酸酶抑制剂的潜力。

The effect of extract of Nepeta angustifolia C.Y.Wu on tyrosinase activity and kinetics

The effect of extract of Nepeta angustifolia C.Y.Wu on tyrosine monophenolase and diphenolase activity and inhibition kinetics were studied by enzymatic reaction using L-tyrosinase and L-DOPA as substrates. Experimental results show that the extract of Nepeta angustifolia C.Y.Wu, has inhibitory effect on tyrosine monophenolase and diphenolase, and the concentrations of the extract of Nepeta angustifolia C.Y.Wu leading to 50% decrease in monophenolase and diphenolase activity(IC50)are calculated to be 0.138 8 and 0.533 2 g/L, respectively. The inhibition of tyrosine diphenolase by the extract of Nepeta angustifolia C.Y.Wu is a reversible process. The Lineweaver-Burk plots show that the type of action is competitive inhibition with an inhibition constant of 504.846 mg/L. The extract of Nepeta angustifolia C.Y.Wu has a significant inhibitory effect on tyrosinase and has the potential to be developed into a natural tyrosinase inhibitor.