荧光法研究高粱红色素清除羟自由基活性

由多种黄酮类化合物组成的天然产物高粱红色素，主要存在于高粱属植物的壳、茎等部位, 广泛应用于食品工业、化妆品和染色等领域，对清除氧自由基、保护人体健康非常重要。通过Cu+催化过氧化氢-抗坏血酸反应体系产生羟自由基模型，根据羟基苯甲酸的荧光大小对比研究了亚硝酸钠、槲皮素和红色素对羟自由基的清除能力。结果表明：高粱红色素、亚硝酸钠、槲皮素对O·H自由基的清除能力呈一定的量效关系，亚硝酸钠、槲皮素优于红色素对羟自由基的清除能力。探讨了红色素、槲皮素、亚硝酸钠的猝灭机理，表明红色素、亚硝酸钠为动态猝灭，槲皮素为静态猝灭过程。本研究可为高粱红色素的合理开发和利用提供一定的参考依据。

Study of Scavenging Activity of Sorghum Pigment to Hydroxyl Free Radicals by Fluorimetry

A natural product,sorghum pigment,consists of a number of important flavonoid derivatives,occurrs on the seed capsules or in the stems of many sorghums,and is widely applied in different fields of food,cosmetic and dyeing industries,It is important for scavenging hydroxyl free radicals and protection of human healthiness.Scavenging capacities of hydroxyl free radicals with sodium nitrite,quercetin and sorghum pigment were comparatively researched by fluorimetry,and the model of hydroxyl free radicals produced is based on the reaction of Cu2 -catalyzed oxidation of ascorbic acid in the presence of hydrogen peroxide.The hydroxyl radicals react with benzoic acid,forming a fluorescent product,and the fluorescence intensity was determined by the concentration of hydroxybenzoic acid.The experimental results show that the sodium nitrite,quercetin and sorghum pigment have a quantity-effect relationship for scavenging hydroxyl free radicals,and sodium nitrite and quercetin in comparison with sorghum pigment have high antioxidant capacity.Finally,the quenching mechanisms were explored with sodium nitrite,sorghum pigment,and quercetin respectively.The sorghum pigment and sodium nitrite feature a dynamic quenching processes,while quercetin shows a static quenching processes.A reference method was provided for reasonable exploitation and utilization of sorghum pigment.