Synthesis of a Glucuronic Acid-Containing Thioglycoside Trisaccharide Building Block and Its Use in the Assembly of Cryptococcus Neoformans Capsular Polysaccharide Fragments.

ABSTRACT: As part of an ongoing project aimed at identifying protective capsular polysaccharide epitopes for the development of vaccine candidates against the fungal pathogen Cryptococcus neoformans, the synthesis and glycosylation properties of a naphthalenylmethyl (NAP) orthogonally protected trisaccharide thioglycoside, a common building block for construction of serotype B and C capsular polysaccharide structures, were investigated. Ethyl (benzyl 2,3,4-tri-O-benzyl-?-d-glucopyranosyl- uronate)-(1?2)-[2,3,4-tri-O-benzyl-?-d-xylopyranosyl-(1?4)]-6-O-benzyl-3-O-(2-naphthalenylmethyl)-1-thio-?-d-mannopyranoside was prepared and used both as a donor and an acceptor in glycosylation reactions to obtain spacer equipped hexa- and heptasaccharide structures suitable either for continued elongation or for deprotection and printing onto a glycan array or conjugation to a carrier protein. The glycosylation reactions proceeded with high yields and ?-selectivity, proving the viability of the building block approach also for construction of 4-O-xylosyl-containing C.?neoformans CPS structures.

SUBMITTER: Guazzelli L 

PROVIDER: S-EPMC4906494 | biostudies-literature | 2015 Dec

REPOSITORIES: biostudies-literature