期刊
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
卷 51, 期 5, 页码 1270-1277出版社
AMER CHEMICAL SOC
DOI: 10.1021/jf020836g
关键词
kaempferol; gamma irradiation; depsides; antioxidant activity
Oxidative reaction between hydroxymethyl radical (.CH2OH) and kaempferol, in methanol and methanol/water mixtures, was studied by gamma-radiolysis using a Co-60 source. Radiolysis was performed with concentrations and doses ranging from 5 x 10(-5) M to 5 x 10(-3) M and from 0.5 kGy to 14 kGy, respectively. Kaempferol degradation was followed by HPLC. Results showed that .CH2OH reacts with kaempferol at the 3-OH group and produces two depsides (K1 and K2) and other products including K3. K1, K2, and K3 were identified by NMR, LC-MS, and HRMS. The kaempferol degradation pathway leading to the K1, K2, and K3 formation is proposed. It was observed that the more water concentration in the irradiation medium increases, the more K2 concentration increases. Comprehension of food preservation is not clear because many phenomena occurring during irradiation are not established. Radiolysis of kaempferol in water/methanol mixtures helps to elucidate the phenomenon and it is possible that during the treatment of nutriments by gamma-irradiation, a series of products such as depside K2 could be formed. Antioxidant properties of kaempferol radiolysis products were evaluated according to their capacity to decrease the EPR DPPH (1,1-diphenyl-2-picrylhydrazil) signal and to inhibit superoxide radicals formed by the enzyme reaction xanthine + xanthine oxidase.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据