Development of a multifunctional neoglycoside auxiliary for applications in glycomics research.

A novel, multifunctional, tetrazine-containing neoglycoside auxiliary has been synthesized in three steps and 28% overall yield. The oxyamine was conjugated with unprotected carbohydrates under aqueous conditions (pH = 4.7), with DMF as a cosolvent, to provide neoglycosides in yields ranging between 51% and 68%. This auxiliary displayed broad advantages in the isolation and purification of complex carbohydrate mixtures, compatibility during extension by glycosyltransferases, and direct conjugation to chemical probes. Furthermore, the auxiliary can be removed in 96% yield under acidic conditions (0.25% TFA in H2O) that leave glycosidic linkages intact. Thereby, the tetrazine-containing neoglycoside auxiliary can serve to facilitate future glycomics investigations.