Cryptococcus neoformans is an opportunistic fungal pathogen that causes severe diseases primarily in immunocompromised individuals (e.g. HIV positive patients).[1] C. neoformans is surrounded by a thick layer of capsular polysaccharides (CPSs), which are an important virulence factor. In order to investigate the immunobiological properties of the fungal CPSs and to develop glycoconjugate vaccines, chemically synthesised part structures of the fungal CPSs are required. Currently, we are focusing on the synthesis of structures related to serotype A and D of the glucuronoxylomannnan (GXM) CPSs. Our strategy is to use thioglycoside donors of varying size as building blocks in the construction of large oligosaccharide structures (up to pentadeca- and octadecasaccharides) in order to determine structure and minimum size of protective epitopes. [2, 3]
Herein, an improved synthetic pathway is presented to assemble a library of spacer-equipped oligosaccharides corresponding to native GXM-structures.
[1] Brummer, E. Mycopathologia, 1999, 143, 121-125.
[2] Oscarson, S.; Alpe, M.; Svahnberg, P.; Nakouzi, A.; Casadevall, A. Vaccine, 2005, 23, 3961–3972.
[3] Nazouki, A.; Zhang, T.; Oscarson, S.; Casadevall, A. Vaccine, 2009, 27, 3513–3518.
