芬顿反应制备低分子量硫酸软骨素及其降解机制  

Preparation of low molecular weight chondroitin sulfate by Fenton method and its degradation mechanism

作　　者：王康宇 王雯芳 侯成立[1] 郭玉杰 张春晖[1] WANG Kangyu;WANG Wenfang;HOU Chengli;GUO Yujie;ZHANG Chunhui(Comprehensive Key Laboratory of Agro-products Processing,Ministry of Agriculture and Rural Affairs,Institute of Food Science and Technology,Chinese Academy of Agricultural Sciences,Beijing 100193,China;State Key Laboratory of Food Nutrition and Safety,College of Food Science and Engineering,Tianjin University of Science&Technology,Tianjin 300457,China)

机构地区：[1]中国农业科学院农产品加工研究所,农业农村部农产品加工综合性重点实验室,北京100193 [2]天津科技大学食品科学与工程学院食品营养与安全国家重点实验室,天津300457

出　　处：《农业工程学报》2023年第21期269-278,共10页Transactions of the Chinese Society of Agricultural Engineering

基　　金：十四五国家重点研发计划项目(2021YFD2100804);国家农业科技创新工程项目(CAAS-ASTIP-2021-IFST)。

摘　　要：为了提高硫酸软骨素(chondroitin sulfate,CS)的生物活性和生物利用率,该研究通过芬顿反应制备了不同来源的低分子量硫酸软骨素(low molecular weight chondroitin sulfate,LMCS)并探究了其潜在降解机制。使用鸡来源的硫酸软骨素(chondroitin sulfate from chicken cartilage,CCS)、牛来源的硫酸软骨素(chondroitin sulfate from bovine cartilage,BCS)、鲨鱼来源的硫酸软骨素(chondroitin sulfate from shark cartilage,SCS),通过单因素试验优化CS的降解条件,随后测定了降解产物的化学组成和结构,并且通过密度泛函理论(density functional theory,DFT)和分子动力学模拟(molecular dynamics,MD)试验探究了其潜在的机制。结果表明,CS的降解条件分别为乙酸铜浓度0.5 mmol、pH值7.5和反应温度45℃。降解产物的单糖和双糖组成结果表明,CS中的硫酸软骨素A(CSA)的GlcA残基在降解反应中可能被优先攻击。红外图谱结果表明CS可能和羟基自由基反应生成了羧基衍生物。分子动力学模拟试验结果表明,CSA比非硫酸化软骨素(non-chondroitin sulfate,CSO)和硫酸软骨素C(CSC)更容易与·OH相互作用。密度泛函数计算表明,GlcA的C1-H(CSO:-65.288 3 kJ/mol、CSA:-69.985 3 kJ/mol、CSC:-64.826 2 kJ/mol)发生抽氢反应所需的能量比GalNAc(CSO:-75.273 1 kJ/mol、CSA:-76.097 5 kJ/mol、CSC:-68.782 9 kJ/mol)的低。这些结果为生产LMCS提供了指导。Chondroitin sulfate(CS)has been widely used as a dietary supplement in the food industry at present.However,there is incomplete absorption in the body,due to the large molecular weight,abundant hydrophilic groups,and low lipid solubility.As a result,CS exhibits low bioavailability(typically less than 13%),when taken orally.The bioavailability of oral CS formulations is closely linked to the molecular weight.Furthermore,the intact CS is still challenging to absorb in the digestive tract,where the low molecular weight CS(LMCS)can be absorbed through the intestine.LMCS can be expected to serve as the superior bioactivity and bioavailability,compared with undegraded CS.Therefore,the preparation of LMCS by degrading CS is of great significance for the further development and utilization of CS.There are several ways to prepare the LMCS so far,including free radical,enzyme,and acid degradation.Among them,the Fenton process is one type of free radical degradation with a commonly used and cost-effective reaction.It can be expected to degrade the CS by catalytic H2O2 while retaining the main polysaccharide structure.In this study,LMCS from different sources was prepared using the Fenton reaction,in order to investigate the potential degradation mechanism.The molecular weight,sulfate,and glyoxylate contents of chondroitin sulfate(BCS)of bovine origin were analyzed under different degradation conditions.The optimal CS degradation was determined using single-factor experiments.Subsequently,chondroitin sulfate derived from chicken(CCS),bovine(BCS),and shark(SCS)were reacted under optimal degradation conditions for 2,4,6,and 8 hours.The contents of sulfate and uronic acid,as well as the mono-and disaccharide composition and structure of the degradation products,were determined using Fourier transform infrared(FT-IR)spectroscopy and high-performance liquid chromatography(HPLC).For the first time,the potential mechanism of CS degradation by the Fenton reaction was analyzed from the perspective of molecular conformation and bond e

关 键 词：降解 硫酸软骨素 芬顿反应 分子动力学模拟 标准密度函数理论 

分 类 号：TS251.1[轻工技术与工程—农产品加工及贮藏工程]