Regioselective synthesis and antioxidant activities of phosphorylated guar gum
Regioselective synthesis and antioxidant activities of phosphorylated guar gum
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DOI：
10.1016/j.ijbiomac.2013.09.047
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发表时间：
2013-11
影响因子：
8.2
通讯作者：
Shengfan Niu;Junlong Wang;Baotang Zhao;Mei-Ping Zhao;Ming-Hao Nie;Xiaofang Wang;Jian Yao;Ji Zhang-Ji-Z
中科院分区：
文献类型：
--
作者：
Shengfan Niu;Junlong Wang;Baotang Zhao;Mei-Ping Zhao;Ming-Hao Nie;Xiaofang Wang;Jian Yao;Ji Zhang-Ji-Z
我们报道了一种非c -6磷酸化瓜尔胶（PRSGG）的区域选择性合成，取代度（DS）为0.34。采用三苯基氯甲烷（TrCl）作为关键保护前驱体。通过过量的二氯乙酸处理进行去三氮化。磷酸化的GG通过FT-IR和13c NMR成功地进行了表征。结果表明，在磷酸化多糖中以C-2和C-3取代为主。在脱保护过程中，由于酸性环境的影响，反应的质量平均摩尔质量（Mw）有所下降。体外抗氧化实验结果表明，C-2/C-3和低分子量的区域选择性磷酸化具有较强的抗氧化活性。非c -6磷酸化瓜尔胶对1,1-二苯基-2-吡啶酰肼（DPPH）和羟基自由基的清除能力明显高于c -6磷酸化瓜尔胶。
We reported here a regioselective synthesis of non-C-6 phosphorylated guar gum (PRSGG) with a degree of substitution (DS) 0.34. Triphenylchloromethane (TrCl) was employed as a key protected precursor. Detritylation was performed by treatment with an excess of dichloroacetic acid. Phosphorylated GG was successfully characterized by FT-IR and13C NMR spectroscopies. It was indicated that C-2 and C-3 substitution was predominant in phosphorylated polysaccharide. A decrease in weight average molar mass (Mw) was observed in the reaction due to the acid environment in deprotection procedure. The results of vitro antioxidant experiments revealed that regioselective phosphorylation at C-2/C-3 and lowMwafforded strong antioxidant activities. Non-C-6 phosphorylated guar gum showed a much higher scavenging abilities of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical than C-6-phosphorylated derivative.