Chemoenzymatic synthesis of a trimeric ganglioside GM3 analogue

Article abstract of DOI:10.1016/S0008-6215(97)00085-2

A trimeric β-lactosyl cluster based on 2-nitro-2-(hydroxymethyl)propane- 1,3-diol was prepared using the trichloroacetimidate method. Kinetic studies showed that this cluster was an effective acceptor for rat-liver α-(2 → 3)-sialyltransferase. Its K(M) was comparable to those for monomeric lactose and N-acetyllactosamine accepters, and its V(MAX) was 1% of that measured for the LacNAc acceptor. Preparative-scale sialylation using this enzyme afforded a trimeric cluster of the ganglioside GM₃ oligosaccharide in good yield. The NMR spectra of the trimeric GM₃ analogue suggest that the oligosaccharide conformation is not significantly perturbed by this level of clustering.