Synthesis and Binding Activity of 3- and 4-Deoxy-N-Acetyl-Galactosamine Derivatives

Abstract
Allyl 3- and 4-deoxy-N-acetyl-β-D-galactosaminides were synthesized from galactosamine and glucosamine, respectively. Using inhibition assay, we found that neither the 3-deoxy nor the 4-deoxy derivative had any binding affinity to the Gal/GalNAc lectins of rabbit and rat liver at the highest concentration tested (40 mM), indicating that the absence of either 3- or 4-hydroxyl group of N-acetyl-galactosamine (GalNAc) caused a decreace in afffinity of at least 100-fold. Therefore, both 3- and 4-hydroxyl groups of GalNAc are required for the binding to the mammalian hepatic lectins.