Determination of amino sugars in synthetic glycopeptides during the conditions of amino acid analysis utilizing precolumn derivatization and high-performance liquid chromatographic analysis.

The growing number of synthetic glycopeptides required an in-house method for the analysis of the final products. A reversed-phase high-performance liquid chromatographic protocol was developed to verify the presence of N-acetylglucosamine and N-acetylgalactosamine in synthetic glycopeptides after hydrolysis and derivatization with 4-dimethylaminoazobenzene-4'-sulphonyl chloride. Different sugar and glycoamino acid standards were used to separate the two carbohydrate moieties, and the location of the derivatized 2-aminoglucose was established by the use of radiolabeled sugar. The utility of the approach is demonstrated by the amino acid analysis of N- and O-glycosylated synthetic peptides and the method could provide an alternative for sugar analysis of glycoproteins.