几种枳壳乙醇提取物对酪氨酸酶抑制作用比较

研究了6种中药枳壳乙醇提取物对酪氨酸酶活力的影响．结果表明：6种中药枳壳乙醇提取物对酪氨酸酶活力均有显的抑制作用，除了绿衣枳壳外，其它5种中药枳壳的提取物随着含量的增大，酶活力呈指数下降．测定导致酶活力下降50％的6种中药枳壳提取物含量(JC50)分别为：0．92mg／mL(绿衣枳壳)、0．96mg／mL(陕西枳壳)、1．30mg／mL(红河橙枳壳)、0．44mg／mL(湖南枳壳)、0．41mg／mL(四川枳壳)、和0．70mg／mL(江西枳壳)，上述6种中药枳壳提取物对酪氨酸酶的抑制作用表现为可逆过程．抑制类型均为混合型，分别测定各种枳壳提取物对游离酶抑制抑制常数(K1)和酶-底物络合物抑制常数(Kis)，并加以比较。

Comparison of the Inhibition of Some Ethanol Extracts from Different Kinds of Fructus aurantii on the Activity of Mushroom Tyrasinase

Fructus aurantii is the dried green fruit of Rutaceae plant.It is used as a kind of traditional Chinese medicine.It was recorded that the extracts from Fructus aurantii could be used as curing the stomachache.In this paper,six sorts of Fructus aurantii: Lvyi,Shanxi,Honghecheng,Hunan,Sichuan and Jiangxi,were used to test.The effects of the extracts from the six sorts of Fructus aurantii by ethanol on the mushroom tyrosinase were studied.The results showed that all of the six extracts could inhibit the activity of tyrosinase obviously.With increasing of content of the extracts,the enzyme activity decreased exponentially except the extract from Poncirus Raf.which enhanced the inhibition at low concentration and weakened it at high concentration.The inhibitor content leading to 50% activity lost,IC_(50s),were estimated to be 0.92 mg/mL for Poncirus Raf.,0.96 mg/mL for C.aurantium Shanxi,1.30 mg/mL for C.hongheensis Y.L.D.L.,0.44 mg/mL for C.aurantium Hunan,0.41 mg/mL for C.aurantium Sichuan and 0.70 mg/ mL for C.aurantium Jiangxi.Kinetics analyses showed that the six extracts of Fructus aurantii inhibited the enzyme reversibly and the inhibition belonged to the mix-typed.The inhibition constants,K_I and K_(IS),of every extracts were determined respectively and compared.