两种新型水溶性异黄酮衍生物的合成与抗氧化活性

合成了未见文献报道的水溶性的3'-磺酸钠-4',7-二羧甲氧基异黄酮(L1)和3'-磺酸钠-4'-羟基-7-羧甲氧基异黄酮(L2), 采用IR, UV, ¹H NMR和元素分析对其结构进行了表征, 利用荧光光谱法研究了它们和母体大豆甙元(D)对羟基自由基的清除活性, 用紫外光谱法研究了其对超氧阴离子自由基和1,1-二苯基-2-苦肼基自由基(1,1-diphenyl-2-picrylhydrazyl free radical, 简称DPPH)的清除活性; 并采用量子化学AM1方法在全几何构型优化的基础上进行了电荷布居分析, 计算了它们抽氢反应的生成热(?H_f), 从而从理论上探讨了目标化合物清除羟基自由基的活性. 实验结果表明本文合成的两种水溶性化合物清除超氧阴离子自由基和DPPH自由基的活性要优于母体大豆甙元, 对于目标化合物清除羟基自由基的活性, 实验和理论结果都显示其清除活性要优于大豆甙元．

Synthesis and Antioxidant Activities of Two New Water Soluble Isoflavone Derivatives

Two water soluble isoflavone derivatives: sodium 4',7-bis(carboxymethoxy)isoflavone-3'-sulfonate (L1) and sodium 4'-hydroxy-7-carboxy-methoxyisoflavone-3'-sulfonate (L2) were synthesized and their structures were characterized by IR, UV, ¹H NMR and elemental analysis. The scavenging activities of L1, L2 and their parent daidzein to hydroxy radicals were detected by fluorescent spectrophotometry, while their scavenging activities on superoxide anion free radicals and 1,1-diphenyl-2-picrylhydrazyl free radical (DPPH?) were measured by ultraviolet spectrophotometry. The scavenging abilities of L1, L2 and daidzein to hydroxy radicals were also studied by quantum chemistry semiempirical calculation methods. The scavenging acitivity sites of L1, L2 and daidzein to hydroxyl radicals were analysed by the charge population of O—H and the difference of heat of formation between an antioxidant and its free radical (?H_f), calculated by the semiempirical AM1 method. The experimental results showed that both L1 and L2 could scavenge hydroxy radicals, superoxide anion free radicals and DPPH? ef-fectively, and the scavenging activities of L1 and L2 were better than that of daidzein. The experimental re-sults were consistent with the calculational results.