黄瑞香中化学成分抑制黄嘌呤氧化酶活性及其机制研究

目的：黄瑞香中化学成分对黄嘌呤氧化酶活性的影响及其机制探讨。方法：以黄嘌呤为底物，别嘌呤醇为阳性药，采用分光光度法测定黄瑞香中的化学成分木犀草素，5，7，3’-三羟基-4’-甲氧基黄酮daphnodorin A（3），瑞香苷对黄嘌呤氧化酶活性的影响，并进一步对上述化合物进行酶抑制类型考察。结果：黄瑞香中化学成分木犀草素，5，7，3’-三羟基-4’-甲氧基黄酮，daphnodorin A，瑞香苷对黄嘌呤氧化酶有明显的抑制作用，且5，7，3’-三羟基-4’-甲氧基黄酮为非竞争性抑制，木犀草素、瑞香苷为竞争性抑制黄嘌呤氧化酶。结论：黄瑞香中的黄酮类和香豆素类成分能够较好的抑制黄嘌呤氧化酶，为黄瑞香治疗痛风奠定了一定的理论基础。

Effect and Mechanism of Chemical Constituents from Daphne giraldii on Inhibiting Xanthinen Oxidase

Objective: To study the inhibitory effect and mechanism of chemical constituents from Daphne giraldii on xanthine oxidase activity. Method: The ultraviolet spectrophotometry was adopted, xanthine as substrate and allopurinol as positive control drug, to measure xanthine oxidase activity affected by four compounds:luteolin(1), 5,7,3'-trihydroxy-4'-methoxy-flavone(2), daphnodorin A(3), daphnin(4) which were isolated from D. giraldii, and further the type of inhibition through enzyme kinetic was exploreds. Result: The compounds had obvious inhibiting effect on xanthine oxidase, among which 5,7,3'-trihydroxy-4'-methoxy-flavone(2)was a noncompetitive inhibitor while luteolin(1), daphnodorin A(3) daphnin(4)were competitive inhibitors. Conclusion: Flavonoids and coumarins in D. giraldii can effectively inhibit xanthine oxidase activity, which can provide theoretical basis for the clinical usage of D. giraldii in treatment of gout.