C_(6)/C_(6+)糖基碳水化合物选择性转化为糠醛的研究

糠醛是一种广泛应用在食品、医药、农药和化工等领域的重要的精细化工品。通常,半纤维素解聚到五碳糖后进一步脱水可转化为糠醛,而纤维素解聚后生成的六碳糖难于转化为糠醛。基于此,实验研究了葡萄糖(C_(6))选择性转化糠醛的影响因素,提出了可能的反应路径;比较了几种典型的C_(6)/C_(6+)糖基碳水合物转化为糠醛的差异。结果表明葡萄糖在硫酸-环丁砜体系中可转化收率为32.6%的糠醛,且糠醛在硫酸-环丁砜体系中保持6.0 h后的浓度依然较为稳定,损失率仅为4.6%。以果糖、蔗糖与纤维素为原料时,可分别得到收率为32.4%、46.5%和43.5%的糠醛。上述结果说明溶剂的性质及其对糠醛的稳定作用,糖基碳水化合物的碳链长度和结构是影响糠醛选择性生成的重要因素。

Synthesis of N(OMe)-linked TF antigen analogue

Tumor-associated carbohydrate antigens （TACAs）, important molecular markers on tumor cells, are major targets for the development of anti-cancer vaccines. However, due to the immunotolerance and weak immunogenicity, native TACAs cannot induce powerful immune response. The use of modified TACAs such as N-glycosides could be an alternative strategy to overcome this problem. Herein, the synthesis of N（OMe）-linked analogue of tumor-associated disaccharide antigen Thomsen-Friedenreich （TF） by the glycosylation reaction is described.