Taxonomic group: fungi / Basidiomycota
(Phylum: Basidiomycota)
Organ / tissue: capsuleAssociated disease: infection due to Cryptococcus neoformans [ICD11:
XN3EH 
];
infection due to Cryptococcus gattii [ICD11:
XN0LE ]
NCBI PubMed ID: 25986781Publication DOI: 10.1039/c5ob00766fJournal NLM ID: 101154995Publisher: The Royal Society of Chemistry
Correspondence: stefan.oscarson
ucd.ie
Institutions: Center for Synthesis and Chemical Biology, University College Dublin, Dublin, Ireland
As part of an ongoing project aimed at developing vaccine candidates against Cryptococcus neoformans the preparation of tri- and tetrasaccharide thioglycoside building blocks, to be used in construction of structurally defined part structures of C. neoformans GXM capsular polysaccharide, was investigated. Using a naphthalenylmethyl (NAP) ether as a temporary protecting group and trichloroacetimidate donors in optimized glycosylations the target building blocks, ethyl 6-O-acetyl-2,4-di-O-benzyl-3-O-(2-naphthalenylmethyl)-α-D-mannopyranosyl-(1→3)-[2,3,4-tri-O-benzyl-β-D-xylopyranosyl-(1→2)]-4,6-di-O-benzyl-1-thio-α-D-mannopyranoside (16) and ethyl 2,3,4-tri-O-benzyl-β-D-xylopyranosyl-(1→2)-4,6-di-O-benzyl-3-O-(2-naphthalenylmethyl)-α-D-mannopyranosyl-(1→3)-[2,3,4-tri-O-benzyl-β-D-xylopyranosyl-(1→2)]-6-O-acetyl-4-O-benzyl-1-thio-α-D-mannopyranoside (21), were efficiently prepared. These synthesized thiosaccharide building blocks were then used as donors in high-yielding (similar to 90%) DMTST promoted glycosylations to a spacer-containing acceptor to, after deprotection, afford GXM polysaccharide part structures ready for protein conjugation to give vaccine candidates. Also, the NAP groups in the building blocks were removed to obtain tri- and tetrasaccharide acceptors suitable for further elongation towards larger thiosaccharide building blocks.
synthesis, vaccine, Thioglycoside, Cryptococcus neoformans, protecting group
Structure type: suggested polymer biological repeating unit
Location inside paper: Fig. 1, B
Trivial name: glucuronoxylomannan (GXM), glucuronoxylomannan
Compound class: CPS, EPS, O-polysaccharide, O-antigen, cell wall polysaccharide, polysaccharide, glucuronoxylomannan, capsule polysaccharide
Contained glycoepitopes: IEDB_114701,IEDB_115136,IEDB_115576,IEDB_130701,IEDB_140116,IEDB_140630,IEDB_144983,IEDB_145668,IEDB_152206,IEDB_164174,IEDB_167188,IEDB_174332,IEDB_2270799,IEDB_423153,IEDB_76933,IEDB_983930,SB_197,SB_44,SB_67,SB_72
Methods: chemical synthesis
Synthetic data: chemical
Comments, role: chemical repeating unit frame was shifted in annotation for compatibility with structures elucidated by MS [Eukaryotic Cell 2007, 6: 1464-1473]
Related record ID(s): 48288, 48290, 48291
NCBI Taxonomy refs (TaxIDs): 37769Reference(s) to other database(s): GTC:G42955PN
Show glycosyltransferases
There is only one chemically distinct structure:
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(later renamed to: Cryptococcus gattii VGI)