Synthesis of chitosan-caffeic acid derivatives and evaluation of their antioxidant activities
Synthesis of chitosan-caffeic acid derivatives and evaluation of their antioxidant activities
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DOI：
10.1016/j.jbiosc.2010.09.018
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发表时间：
2011-02-01
影响因子：
2.8
通讯作者：
Kida, Kenji
中科院分区：
文献类型：
--
作者：
Aytekin, Ali Ozhan;Morimura, Shigeru;Kida, Kenji
本文研究了不同分子量和接枝率的壳聚糖-咖啡酸衍生物的抗氧化活性。以1-乙基-3-（3-二甲氨基丙基）碳二亚胺盐酸盐（EDAC）为共价连接剂，在壳聚糖分子量、壳聚糖与咖啡酸的摩尔比、反应温度、pH值和反应时间等条件下进行接枝反应。通过在自由基清除试验中还原1，1-二苯基苦基肼和在还原力试验中将Fe 3 +/铁氰化物复合物还原为亚铁形式来计算产物的半抑制浓度（IC 50）。EDAC在3 h、pH 5.0和室温条件下表现出最大活性，但高分子量壳聚糖在pH 2.0时表现出最大活性。该产品是水溶性的，在所有的pH值，并表现出较低的粘度比天然壳聚糖。在低分子量壳聚糖中，咖啡酸的接枝率在15%时最高。在相同条件下，将咖啡酸接枝到壳聚糖上，接枝率随壳聚糖分子量的降低而提高。咖啡酸在产品的抗氧化活性中起主要作用。自由基清除活性的最大IC 50（0.064 mg/ml）在含咖啡酸的衍生物最高时观察到。通过本研究得到了水溶性壳聚糖和咖啡酸衍生物，而没有活性损失。(C)2010年，生物技术学会，日本。All rights reserved.
In this study, the antioxidant activities of different molecular weights (M-w) and grafting ratios of chitosan-caffeic acid derivatives were investigated. The grafting process was achieved using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDAC) as covalent connector under different conditions such as molecular-weight of chitosan, molar ratio of chitosan and caffeic acid, reaction temperature, pH, and reaction time. The half-inhibition concentrations (IC50) of products were calculated by reduction of the 1,1-diphenyl picryl hydrazyl in the radical-scavenging assay and reduction of the Fe3+/ferricyanide complex to the ferrous form in reducing power assay. The EDAC showed maximum activity at 3-h, pH 5.0 and room temperature conditions, except high-molecular-weight chitosan in pH 2.0. The products were water-soluble in all pH and showed lower viscosity than native chitosan. The highest grafting ratio of caffeic acid was observed at 15% in low-molecular-weight chitosan. After 5% grafting of caffeic acid into chitosan, the grafting efficiency was increased by decreasing molecular-weight of chitosan at the same conditions. Caffeic acid has main role in the antioxidant activity of products. The maximum IC50 of radical-scavenging activity (0.064 mg/ml) was observed at the highest caffeic acid containing derivative. Water-soluble chitosan and caffeic acid derivatives were obtained by this study without activity loss. (C) 2010, The Society for Biotechnology, Japan. All rights reserved.