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低聚壳聚糖经化学改性得到三种取代度不同的N-琥珀酰低聚壳聚糖(NSCOSA、NSCOSB和NSCOSC,取代度(DS)分别是为0.25、0.57和0.70。对其结构进行红外表征,并且并考察了其对超氧阴离子自由基(O-·2)、羟基自由基(·OH)、DPPH的清除活性以及还原能力。结果表明:N-琥珀酰低聚壳聚糖衍生物的抗氧化活性与低聚壳聚糖相比有所降低。随着DS的升高,琥珀酰衍生物对·OH的清除能力下降;对O-·2的清除能力大小顺序为NSCB>NSCA>NSCC;对DPPH的清除能力以及还原能力大小顺序均为:NSCA>NSCC>NSCB。这可能是由于N-琥珀酰低聚壳聚糖的取代度、引进基团的性质以及对自由基的清除机理不同所致。
Chitosan oligosaccharides were chemically modified to give three kinds of N-succinyl oligosaccharides with different degrees of substitution (NSCOSA, NSCOSB and NSCOSC, the degree of substitution (DS) were 0.25,0.57 and 0.70 for the structure of IR and their scavenging activities on superoxide anion radical (O- · 2), hydroxyl radical (· OH), DPPH and their reducing ability were also investigated.The results showed that N-succinyl oligosaccharide derivative The antioxidant activity of the product decreased as compared with that of the oligochitosan.With the increase of DS, the scavenging ability of succinyl derivatives to · OH decreased, and the order of scavenging ability to O · 2 was NSCB> NSCA > NSCC, and the order of scavenging capacity and reducing ability of DPPH were: NSCA> NSCC> NSCB.This may be due to the degree of substitution of N-succinyl oligochitosan, the nature of the introduced groups and the elimination of free radicals Due to different mechanisms.