Preparation of neoglycolipids with a definite sugar chain moiety from glycoproteins

A method for preparing neoglycolipids possessing a sugar chain with a definite structure using two N-linked sugar chains as model compounds was developed. Pyridylaminated sugar chains obtained from glycoproteins were purified by reversed-phase HPLC and a pyridylaminated sugar chain thus obtained was converted to a 1-amino-1-deoxy derivative. The product was conjugated by reductive amination with phosphatidylglycolaldehyde prepared by periodate oxidation of dipalmitoyl phosphatidylglycerol. Neoglycolipids formed were purified by gel filtration from the reaction mixture. The structures of the purified neoglycolipids were confirmed by composition analysis for sugar, fatty acid, phosphorus, and 2-acetamido-1,2-dideoxy-1-[(hydroxyethyl)amino]-D-glucitol, the linkage region of the sugar chain, and lipid moieties. The method provides a convenient means of preparing neoglycolipids having a definite structure.