Synthesis of sialyllactosamine clusters using carbosilane as core scaffolds by means of chemical and enzymatic approaches

An efficient synthesis of sialyllactosamine (SiaLacNAc) clusters using carbosilanes as core scaffolds has been accomplished by means of chemical and enzymatic approaches. N-Acetyl-D-glucosamine (GlcNAc) clusters having O-glycosidic linkage or S-glycosidic linkage were chemically synthesized from known intermediates in high yields. The GlcNAc clusters were first used as substrates for beta 1,4 galactosyl transferase using UDP-galactose (UDP-Gal) as a sugar source to provide corresponding N-acetyllactosamine clusters. Further sugar elongation of the LacNAc clusters was demonstrated using alpha 2,3 sialyl transferase and CMP-neuraminic acid (CMP-NANA) to yield the corresponding SiaLacNAc clusters. (c) 2010 Elsevier Ltd. All rights reserved.