Chen Szu Kai, Tsai Min Lang, Huang Jin Ru, Chen Rong Huei
Department of Food Science, National Taiwan Ocean University, 2 Pei-Ning Road, Keelung, Taiwan 20224, Republic of China.
J Agric Food Chem. 2009 Apr 8;57(7):2699-704. doi: 10.1021/jf804010w.
The objectives of this study were to evaluate the effect of different functional groups of sulfate, amine, and hydroxyl and/or their ionized groups on in vitro antioxidant capacities of low-molecular-weight polysaccharides (LMPS) prepared from agar (LMAG), chitosan (LMCH), and starch (LMST), respectively, and to elucidate their structure-activity relationship. Ascorbic acid and ethylenediaminetetraacetic acid (EDTA) were used as positive controls. The in vitro antioxidant capacities of LMAG and LMCH were higher than that of LMST in the DPPH radical, superoxide radical, hydrogen peroxide, and nitric oxide radical scavenging and ferrous metal-chelating capacities. The different scavenging capacities may be due to the combined effects of the different sizes of the electron-cloud density and the different accessibility between free radical and LMPS, which, in turn, depends upon the different hydrophobicities of the constituent sugars.
本研究的目的是分别评估硫酸盐、胺和羟基的不同官能团及其离子化基团对由琼脂（LMAG）、壳聚糖（LMCH）和淀粉（LMST）制备的低分子量多糖（LMPS）体外抗氧化能力的影响，并阐明其构效关系。以抗坏血酸和乙二胺四乙酸（EDTA）作为阳性对照。在DPPH自由基、超氧阴离子自由基、过氧化氢和一氧化氮自由基清除以及亚铁离子螯合能力方面，LMAG和LMCH的体外抗氧化能力高于LMST。不同的清除能力可能是由于电子云密度大小不同以及自由基与LMPS之间的可及性不同共同作用的结果，而这又取决于组成糖类的不同疏水性。
