Synthesis of blood group pentasaccharides ALey, BLey and related tri- and tetrasaccharides

Recent advances in chemoenzymatic synthesis of human ABO blood group antigens

ABO blood group antigens (namely, A, B, and H antigens) are carbohydrate epitopes on cell surface that play important roles in biological processes and blood transfusion. The structure diversity of ABH antigens structures is associated with susceptibility to different pathogen infections. Advanced synthetic methodologies are required for studying and applying ABO blood group antigens. The existing methods include chemical, enzymatic and chemoenzymatic synthesis. As an alternative approach to chemical synthesis, enzymatic synthesis provides a simple pathway to access oligosaccharide antigens under extremely mild reaction conditions, thereby avoiding laborious protecting group manipulation procedures. Enzymatic synthesis of human blood group antigens primarily relies on Leloir glycosyltransferases, alongside several glycosidases and glycoside phosphorylases. This review aims to discuss recent advancements in chemical, enzymatic and chemoenzymatic synthesis of human ABH antigens, with a particular focus on novel developments in enzymatic assembly of naturally occurring ABH antigens.

ANALYSIS OF CARBOHYDRATES AND GLYCOCONJUGATES BY MATRIX-ASSISTED LASER DESORPTION/IONIZATION MASS SPECTROMETRY: AN UPDATE FOR 2015-2016

This review is the ninth update of the original article published in 1999 on the application of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2016. Also included are papers that describe methods appropriate to analysis by MALDI, such as sample preparation techniques, even though the ionization method is not MALDI. Topics covered in the first part of the review include general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation and arrays. The second part of the review is devoted to applications to various structural types such as oligo- and poly-saccharides, glycoproteins, glycolipids, glycosides and biopharmaceuticals. Much of this material is presented in tabular form. The third part of the review covers medical and industrial applications of the technique, studies of enzyme reactions and applications to chemical synthesis. The reported work shows increasing use of combined new techniques such as ion mobility and the enormous impact that MALDI imaging is having. MALDI, although invented over 30 years ago is still an ideal technique for carbohydrate analysis and advancements in the technique and range of applications show no sign of deminishing. © 2020 Wiley Periodicals, Inc.