Masuoka Noriyoshi, Isobe Takahiko, Kubo Isao
Department of Biochemistry, Okayama University Graduate School of Medicine and Dentistry, Okayama 700-8558, Japan.
Phytother Res. 2006 Mar;20(3):206-13. doi: 10.1002/ptr.1835.
The antioxidant activities of phenolic compounds: pedalitin, quercetin, rutin, isoquercitrin, and rosmarinic acid, isolated from the dried leaves of Rabdosia japonica Hara (Labiatae) were elucidated. All the phenolics tested exhibited superoxide scavenging activity and an inhibitory effect on xanthine oxidase (EC 1.1.3.22), and pedalitin showed the most potent antioxidant activity. Pedalitin prevents the generation of superoxide radicals in part by inhibiting xanthine oxidase competitively. Both pedalitin and quercetin inhibited uric acid formation by xanthine oxidase, and the inhibition kinetics analysed by Lineweaver-Burk plots found both flavonoids to be competitive inhibitors. On the other hand, isoquercitrin, rutin and rosmarinic acid were effective in scavenging superoxide radicals generated by the xanthine-xanthine oxidase system without inhibiting the enzyme.
对从狭叶香茶菜（唇形科）干燥叶片中分离出的酚类化合物——踏板花素、槲皮素、芦丁、异槲皮苷和迷迭香酸的抗氧化活性进行了阐明。所有测试的酚类物质均表现出超氧阴离子清除活性以及对黄嘌呤氧化酶（EC 1.1.3.22）的抑制作用，其中踏板花素显示出最有效的抗氧化活性。踏板花素部分通过竞争性抑制黄嘌呤氧化酶来阻止超氧阴离子自由基的产生。踏板花素和槲皮素均抑制黄嘌呤氧化酶形成尿酸，通过Lineweaver-Burk图分析抑制动力学发现这两种黄酮类化合物均为竞争性抑制剂。另一方面，异槲皮苷、芦丁和迷迭香酸在不抑制该酶的情况下，对黄嘌呤-黄嘌呤氧化酶系统产生的超氧阴离子自由基具有清除作用。
Zotero 插件