壳聚糖硫酸酯金属配合物的抗氧化活性

Antioxidant activity of the complexes of sulfation chitosan with metalion

以吩嗪硫酸甲酯-NADH为超氧阴离子自由基(O2.-)产生、检测体系和EDTANa2-Fe(Ⅱ)-H2O2为羟自由基(.OH)产生、检测体系,对壳聚糖硫酸酯铜、锌配合物和不同分子质量壳聚糖进行了抗O2.-和.OH自由基的活性研究。结果表明,壳聚糖硫酸酯金属配合物对于O2.-自由基的清除能力明显高于壳聚糖,在质量浓度为0.025 g/L时,壳聚糖硫酸酯铜配合物对O2.-自由基的清除能力达到94.18%,壳聚糖硫酸酯锌配合物达到93.19%;壳聚糖硫酸酯铜、锌配合物对.OH自由基的清除能力(67.39%、60.46%)低于相同分子质量的壳聚糖(88.06%),而高于高分子质量壳聚糖761 ku(18.71%);壳聚糖分子质量大小对O2.-和.OH自由基的清除能力有较大影响,质量浓度为1.6 g/L壳聚糖分子质量为20 ku时,对O2.-清除率达54.69%,而分子质量在761 ku时,对O2.-清除率仅为35.50%;各样品对O2.-和.OH自由基的清除能力均随着质量浓度的增加而上升,壳聚糖硫酸酯铜、锌配合物在相当低的浓度下(0.025 g/L)就可以达到明显清除O2.-自由基的效果(≥90%)。

The O2^·-and · OH scavenging activities of the complexes of sulfation chitosan with copper（ Ⅱ ） or zinc（ Ⅱ ） and DMW chitosan were investigated. Colorimetric method was used, where phenzine methosulphate （PMS）/dinucleotide reduced （NADH） and Fe/H2O2 were used as producing reagents and Nitro blue tetrazolium （NBT） and Fanhonghua as detecting reagents for O2^·-and · OH. As expected, we obtained several satisfying results, as follow： Firstly, compared with DMW chitosan, the complexes of sulfation chitosan with copper （ Ⅱ ） or zinc （Ⅱ） had the stronger inhibition effect on O2^·-. For example, when mass concentration of samples was 0. 025 g/L, the O2^·- scavenging activity of the complexes of sulfation chitosan with copper（ Ⅱ ） and the complexes of sulfation chitosan with zinc（ Ⅱ） were 94.18% and 93.19% respectively. Secondly, scavenging activity of the complexes of sulfation chitosan with copper（ Ⅱ ） or zinc（ Ⅱ ） （67.39%, 60.46%, 3.2 g/L） on · OH was between low molecular weight chitosan （20 ku,88.06 %, 3.2 g/L） and high molecular weight chitosan （761 ku, 18.71%, 3.2 g/L）. Thirdly, low molecular weight chitosan had stronger scavenging effect on O2^·-and · OH than high molecular weight chitosan. At 1. 6 g/L, the scavenging activity of low molecular weight chitosan （20 ku） on O2^·- reached 54. 69%, while that of high molecular weight chitosan （761 ku ） was 35.50 %. Finally, the scavenging activity of several samples increased with increase in their mass concentration. However, the complexes of sulfation chitosan with copper（Ⅱ ） or zinc（ Ⅱ ） had a quite strong scavenging action to O2^·- , their scavenging activity barely had obvious changing over 0. 025 g/L. This result also showed that the complexes of sulfation chitosan with metalion were very effective antioxidant.