Synthesis of bioactive sialosides

Abstract

Abstract

Synthesis of Solid-Supported Mirror-Image Sugars: A Novel Method for Selecting Receptors for Cellular-Surface Carbohydrates

“…Compound 1 was further linked to L ‐galactose to provide 2 . D ‐NeuNAc‐ α ‐(2→3)‐ D ‐Gal exists as a common moiety in typical tumor‐associated glycosphingolipid antigens and the binding site of influenza virus hemagglutinin 3, 25. The enantiomer 2 was synthesized by coupling of the L ‐sialyl phosphite 9 with 6‐TBDPS‐1‐ O ‐allyl‐ L ‐galactose ( 10 ), which was prepared from L ‐galactose via 1‐ O ‐allyl‐2,3,4,6‐tetraacetate‐ L ‐galactose ( 12 ) as shown in Scheme .…”

The Chemistry of Sialic Acid

“…Glycosides of N-acetylneuraminic acid can be introduced by similar glycosylation approaches, and these coupling procedures are classified as direct methods [30,55,[67][68][69]. The use of glycosyl donors of Neu5Ac is complicated, however, by the fact that there is no C-3 functionality present to direct the stereochemical outcome of glycosylations.…”

“…The need for increasingly efficient methods for oligosaccharide synthesis has stimulated the development of enzymatic approaches [6,28,29,68,69,144,154,[195][196][197][198][199][200][201][202][203][204][205][206]. These enzymatic methods bypass the need for protecting groups since they govern both the regioselectivity and the stereoselectivity of glycosylations.…”

Hydrolysis and Formation of Glycosidic Bonds

“…Some SiaTs accept CMP-NeuAc analogs which are derivatized at the 9-position with amino, fluoro, azido, acetamido, or benzamido . zido-, phthalimido-, carbamate, and pivaloyl analogs of LacNAc and Galpl,3GalNAc are also substrates for the enzymes [172]. Sialyltransferases have been used to append NeuAc to galactose on the terminus of glycopeptides ['"I, glycolipids…”