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目的:合成罗望子多糖硒酸酯,并表征其结构特征。方法:在HNO3-BaCl2催化作用下,利用亚硒酸钠合成罗望子多糖硒酸酯,以硒含量为指标对合成工艺进行优选,采用红外吸收光谱、热重分析、GPC等方法对合成产物进行表征。结果:罗望子多糖硒酸酯最佳合成条件为硝酸浓度为0.5%,反应温度80℃,反应时间14 h,此条件下产物硒含量约为22 mg.g-1,结论:合成产物中硒以Se=O的形式存在,且与纯多糖比较,多糖硒酸酯热稳定性和相对分子质量稍有降低,可能是由于酸性反应体系下罗望子多糖稍有降解,同时引入的亚硒酸基对分子结构产生了影响。
Objective: To synthesize tamarind polysaccharide selenate and characterize its structure. Methods: Under the catalysis of HNO3-BaCl2, sodium selenite was used to synthesize selenate of tamarind polysaccharides, and the selenium content was taken as the index to optimize the synthesis process. The synthesized products were characterized by infrared absorption spectroscopy, thermogravimetric analysis and GPC Characterization. Results: The optimal synthesis conditions of tamarind polysaccharide selenate were as follows: the concentration of nitric acid was 0.5%, the reaction temperature was 80 ℃ and the reaction time was 14 h. The content of selenium in this condition was about 22 mg.g-1. Conclusion: In the form of Se = O, the thermal stability and molecular weight of polysaccharide selenate decreased slightly compared with pure polysaccharides, which may be due to the slight degradation of tamarind polysaccharides in acid reaction system and the simultaneous introduction of selenite Have an impact on the molecular structure.