不同取代度N-邻苯二甲酰壳聚糖抗氧化活性的研究

低聚壳聚糖与邻苯二甲酸酐酰化得到三种取代度不同的N-邻苯二甲酸酐酰低聚壳聚糖NPCOSA、NPCOSB和NPCOSC,取代度分别为0.330、.55和0.65。通过红外光谱对其结构进行表征。并考察了其抗氧化性能。结果表明:COS的抗氧化性能最强;随着取代度的增加,N-邻苯二甲酰低聚壳聚糖对超氧阴离子的清除能力逐渐升高;而对DPPH的清除能力以及还原能力呈逐渐下降趋势;对羟基自由基的清除顺序大小依次为NPCOSB>NPCOSA>NPCOSC,即NPCOSB清除羟基自由基的的能力最佳。

Antioxidant Activity of N-Phthaloyl-Chitosan Oligosaccharide with Different Substituting Degrees

N-phthaloyl chitosan oligosaccharides(NPCOSA,NPCOSB and NPCOSC),having various degrees of substitution(DS were 0.33,0.55 and 0.65,respectively)were prepared by chemical modification of chitosan oligosaccharide.The chemical structures of the chitosan oligosaccharides derivatives were characterized by FTIR.Their antioxidant activities were evaluated by the scavenging of superoxide anion radicals(O-·2),hydroxyl radical(·OH),DPPH radical and deter mination of reducing power.The results indicated that all the N-phthaloyl chitosan oligosaccharides showed lower antioxidant activity than chitosan oligosaccharides,the scavenging effect on O-·2 increased with the increasing of DS,and their scavenging effect on DPPH and reducing power both were decreased with the increasing of DS;the order of their scavenging effect on ·OH was NPCOSB>NPCOSA>NPCOSC,and the NPCOSB showed the strongest scavenging effect on ·OH.