摘要
类胡萝卜素是一大类天然抗氧化剂,但目前对于其清除自由基活性的研究还不系统,所报道结果也不统一。本实验对常用的两种清除自由基活性的测定方法,DPPH和ABTS法,进行了类胡萝卜素适用性的研究。采用7种类胡萝卜素与槲皮素作为研究对象,分别考察了其清除DPPH和ABTS自由基的能力及其光谱学特征,并优化活性测定条件。结果表明,采用DPPH测定法时,部分有色类胡萝卜素由于其最大吸收峰在450~550 nm之间,与DPPH溶液最大吸收峰接近,会对实验结果产生干扰;而采用ABTS测定法时,最佳测定波长为734 nm,体系在180 min内保持稳定。7种类胡萝卜素在734 nm处吸光值随样品浓度的增加而降低,具有显著量效关系。经测定获得了7种类胡萝卜素与槲皮素清除ABTS自由基的半数抑制浓度(IC50)分别为β-胡萝卜素1251,番茄红素1280,虾青素141,槲皮素22.21,叶黄素386,玉米黄素476,藏红花素596,杜鹃红素42μg·mL^-1。清除ABTS自由基的能力由大到小排列为:槲皮素>杜鹃红素>虾青素>叶黄素>玉米黄素>藏红花素>β-胡萝卜素>番茄红素。ABTS清除实验避免了有色抗氧化剂本身的光谱干扰,相比DPPH自由基清除测定而言,更可靠、方便,更适合作为类胡萝卜素清除自由基性测定方法之一。
Carotenoids are a large class of natural antioxidants,but the current research on their ability to scavenge free radicals is not systematic,and the reported results are not uniform.In this experiment,the commonly used two methods for the determination of free radical scavenging activity,DPPH and ABTS,were used to study the applicability of carotenoids.Seven kinds of carotenoids and quercetin were used as research objects,and their ability to scavenge DPPH and ABTS free radicals and their spectral characteristics were investigated,and the conditions for activity determination were optimized.The results showed that when the DPPH assay was used,some of the colored carotenoids had a maximum absorption peak between 450 nm and 550 nm,which was close to the maximum absorption peak of the DPPH solution,which would interfere with the experimental results.When using the ABTS assay,The optimum measurement wavelength is 734 nm and the system remains stable for 180 min.The absorbance of 7 carotenoids at 734 nm decreased with increasing sample concentration,which showed a significant dose-effect relationship.The half-inhibitory concentration(IC50)of 7 carotenoids and quercetin to remove ABTS free radicals was determined to beβ-carotene 1.27,lycopene 2.58,astaxanthin 0.27,quercetin clearance 0.01,lutein 1.74,zeaxanthin 0.42,crocin 1.65,rhododendrin 0.13 mg·mL^-1.The ability to scavenge ABTS free radicals is ranked from large to small:quercetin>azadirachtin>astaxanthin>lutein>zeaxanthin>crocin>β-carotene>lycopene.The ABTS removal experiment avoids the spectral interference of the colored antioxidant itself,and is more reliable and convenient than the DPPH radical scavenging assay,and is more suitable as one of the methods for determining the free radicality of carotenoids.
作者
羌宇
张耀宗
余勃
陆豫
QIANG Yu;ZHANG Yaozong;YU Bo;LU Yu(College of chemistry,Nanchang University,Nanchang 330031,China;Sino-German Joint Research Institute,Nanchang University,Nanchang 330047,China)
出处
《南昌大学学报（理科版）》
CAS
北大核心
2019年第6期543-549,共7页
Journal of Nanchang University(Natural Science)
基金
国家自然科学基金资助项目(31860432)。
作者简介
羌宇(1995-),女,硕士生;通信作者:陆豫(1958-),男,教授,博士,E-mail:luyzsu@hotmail.com。
