κ-卡拉胶邻苯二甲酰基化衍生物的抗氧化活性研究

Antioxidant Activity of Phthaloyl Derivative of κ-Carrageenan Oligosaccharides

对κ-卡拉胶进行酸降解得到三种卡拉胶低聚糖,并进一步与苯二甲酰基合成制得三种分子量分别为1450、2520和3430的κ-卡拉胶邻苯二甲酰衍生物(LA、LB和LC)。对产物进行IR表征并对其取代度(DS)进行测定,并检测了产物对羟基自由基.OH、DPPH自由基和过氧化氢的清除活性以及还原能力。结果表明,上述三种κ-卡拉胶邻苯二甲酰衍生物的抗氧化能力强弱顺序依次为:LC>LA>LB,这可能与衍生物的羟基含量、取代基团的性质以及取代度等因素有关。

Three κ-carrageenan oligosaccharides were prepared by acidic degradation of κ-carrageenan.Their phthaloyl derivatives with different molecular weight（LA∶1450;LB∶2520;LC∶3430） were synthesized with phthalic anhydride.The products were characterized by FI-IR,and the degrees of acylation（DS） were determined.Their antioxidant activities were evaluated by the scavenging of hydroxyl radical,1,1-diphenyl-2-picrylhrazyl radicals （DPPH）,hydrogen peroxide and reducing power.The results indicated that the orders of antioxidant activities were：LC LA LB.It may be related to the content of hydroxyl groups,the nature of substituting group and the substituting degrees.