Chemoenzymatic synthesis of lacto-N-tetrasaccharide and sialyl lacto-N-tetrasaccharides.

A concise and practical chemoenzymatic synthesis of lacto-N-tetraose, a major component and one of the most common core structures of human milk oligosaccharides (HMOs) was reported. This convergent synthesis relies on the glycosylation of a readily available lactoside acceptor with a lacto-N-biose donor generated from a highly efficient one-pot two-enzyme synthesis.