Establishment of general procedure to synthesize polysialogangliosides and its application for neurobidogy.

鞘糖脂是真核细胞特有的膜成分，由于含有一个或多个唾液酸残基而有别于其他糖鞘脂类，在许多生物学过程中发挥着重要作用，特别是在神经系统中。我们已经成功地建立了合成多唾液酸神经节苷脂的一般程序。1.高效构建低聚唾液酸链，利用1，5-内酰胺化唾液酸受体，高产率地获得了α(2-4)-和α(2-8)双唾液酸序列。2.寡糖与神经酰胺通过分子内糖苷元的不同偶联反应，神经酰胺与琥珀酸连接成葡萄糖，还原寡糖的末端，使寡糖与神经酰胺有效偶联。得到的葡萄糖神经酰胺与唾液酸寡糖进一步糖基化，得到所需的神经节苷脂。

Glycosphingolipids are characteristic membrane components of eukaryotic cells where they are distinguished from other glycosphingolipids by containing one or more sialic acid residues, and have been recognized play important roles in many biological processes, particularly in nervous system We have succeeded in the establishment of general procedunes to synthesize polysialogangliosides. The achievements are summarized in the following two parts.1.Efficient construction of polysialo-oligosaccharides.α(2-4)- and α(2-8)disialic acid seguences were obtained in high yields by employing 1,5-lactamized sialyl acceptors. The disaccharides obtained were utilized for the construction of sialo-oligosaccharides.2.The coupling of oligosaccharides and ceramides by intramolecular-aglycon derivery.Tethering of ceramide to glucose, reducing terminal of oligosaccharides, with succnic acid allowed the efficient coupling of oligosaccharides and ceramides. The glucosyl ceramide obtained was further glycosylated with sialo-oligosaccharides as building bloks to give the desired gangliosides.