玄参中苯丙素苷对脱氧核苷酸羟基加成自由基的快速修复作用(英文)

目的:探讨玄参化学成分的抗氧化作用.方法:应用多种层析方法和化学和光谱方法,对玄参的水溶性主要成分进行分离和结构鉴定.应用脉冲辐解方法,观察分离得到的主要单体成分对脱氧核苷酸dAMP和dGMP羟基加成自由基的快速修复过程,测定苯丙素苷与羟基加成自由基的反应速率常数.结果:从玄参水溶性部位分得四种主要成分,发现它们属于环烯醚萜苷:哈帕酯苷与哈帕苷,和苯丙素苷:安格洛苷C与acteoside.脉冲辐解实验中观察到在0.1 mmol·L~(-1)时,苯丙素苷安格洛苷C与acteoside对脱氧核苷酸羟基加成自由基产生显著的修复作用,而环烯醚萜苷:哈帕酯苷与哈帕苷在相同条件下作用不明显.安格洛苷C与dAMP及dGMP间的电子转移速率常数为4.2×10~8及10.3×10~8 L·mol~(-1)·S~(-1);acteoside与dAMP及dGMP间的电子转移速率常数为5.3×10~8及20.2×10~8 L·mol~(-1)·S~(-1).结论:玄参中的苯丙素苷在还原脱氧核苷酸的氧化性羟基加成自由基方面有很好的抗氧化作用.

Fast repairing of oxidized OH radical adducts of dAMP and dGMP by phenylpropanoid glycosides from Scrophularia ningpoensis Hemsl

AIM: To investigate the antioxidative activity of the constituents of the roots of Scrophularia ningpoensis (Chinese name: Xuanshen). METHODS: The main compounds from the roots of Scrophularia ningpoensis were isolated and identified by chromatography and FABMS, NMR etc. Using the techniques of pulse radiolysis, the electron transfers from iridoid glycosides (IG) or phenylpropanoid glycosides (PG) to oxidized OH radical adducts of 2'-deoxyadenosine-5'-monophosphate acid (dAMP) or 2'-deoxyguanosine-5'-monophosphate acid (dGMP) were observed. RESULTS: Two IG: harpagoside and harpagide, two PG: angoroside C and acteoside were obtained as the main hydrophilic constituents of the plant. At 0.1 mmol/L concentration, angoroside C and acteoside were able to repair the oxidized OH adducts dAMP and dGMP significantly. However, harpagoside and harpagide had no such effect. The electron transfer rate constants of angoroside C with dAMP and dGMP were 4.2 x 10(8) and 10.3 x 10(8) L.mol-1.s-1; the electron transfer rate constants of acteoside with dAMP and dGMP were 5.3 x 10(8) and 20.2 x 10(8) L.mol-1.s-1. CONCLUSION: PG from Scrophularia ningpoensis have a potent antioxidative activity for reducing of the oxidized OH adducts of dAMP and dGMP.