An efficient route to prepare L-glucose and L-galactose is described.The L-sugars are achieved by using the strategy of switching the functional groups at C1 and C5 of D-glucose and D-mannose.The oxidation and reduction of the silyl enol ether at C1 and the lead(IV) tetraacetate mediated oxidative decarboxylation at C5 are the key steps.L-Glucose and L-galactose are prepared in a convenient and inexpensive way.
Tian-Yu XiaYang-Bing LiZhao-Jun YinXiang-Bao MengShu-Chun LiZhong-Jun Li
We utilized the glycosyl acceptor tagging method with ionic liquid support for synthesis of the core segment of Clostridium botulinum C2 toxin ligand through a divergent synthetic strategy without chromatographic purification.The total yield was 57.1% and the reaction was completed in 10 h.The efficient ionic liquid supported glycosylation and purification procedure was applied for the synthesis of branched glucosamine-containing oligosaccharides for the first time,which expanded the scope of ionic liquid supported synthesis of biologically important oligosaccharides.
Ze-Shen GaoSheng SunWei LiQing MaQing LiZhong-Jun Li
免疫监视学说最早是由Ehrlich于1909年提出的，其认为免疫系统的一个关键作用是识别并清除肿瘤，之后又不断有学者（ Burnet and Thomas ）完善免疫监视学说理论，认为免疫系统能够清除新生的肿瘤病变［1］。而肿瘤能够逃避免疫监视则被视为肿瘤的十大特征之一［2］。尽管免疫监视理论目前仍有争议，T细胞在体内抑制肿瘤发生发展中扮演的重要角色却已得到公认［3，4］。本文将针对T细胞和肿瘤的相互作用做一综述，为理解肿瘤如何逃避T细胞的免疫监视作用提供参考。
A new carrier containing three hydrophobic octadecyls was employed to improve the yield and purity of the synthesized oligosaccharides, and the applicability of hydrophobic carrier for HASP(hydrophobically assisted switching phase) was also explored. High performance liquid chromatography(HPLC) was used to analyze the purity of oligosaccharides and improve the elution efficiency. Elution system was optimized and replaced by isopropyl alcohol and water, in which the excess donor and other impurities had a better solubility than that in methanol.
Yunhe WangShuai MengTingting YueShuchun LiZhongjun Li
