Taxonomic group: fungi / Basidiomycota
(Phylum: Basidiomycota)
Associated disease: infection due to Cryptococcus neoformans [ICD11:
XN3EH 
]
NCBI PubMed ID: 15220088Journal NLM ID: 0043535Publisher: Elsevier
Correspondence: fzkong
mail.rcees.ac.cn
Institutions: Research Center for Eco-Environmental Sciences, Academia Sinica, PO Box 2871, Beijing 100085, China
β-D-Xylp-(1→4)-α-D-manp-(1→3)-[β-D-Xylp-(1→2)]-α-D-man p-(1→3)-[β-D-Xylp-(1→2)]-α-D-manp, the fragment of the exopolysaccharide from Cryptococcus neoformans serovar B, was synthesized as its methyl glycoside. Thus, acetylation of allyl 3-O-benzoyl-4,6-O-benzylidene-α-D-mannopyranoside (1) followed by debenzylidenation and selective 6-O-benzoylation afforded allyl 2-O-acetyl-3,6-di-O-benzoyl-α-D-mannopyranoside (4). Glycosylation of 4 with 2,3,4-tri-O-benzoyl-d-xylopyranosyl trichloroacetimidate (5) furnished the β-(1→4)-linked disaccharide 6. Deallylation followed by trichloroacetimidate formation gave the disaccharide donor 8, and subsequent coupling with allyl 2,3,4-tri-O-benzoyl-β-D-xylopyranosyl-(1→2)-4,6-di-O-benzoyl-α-d-mannopyranoside (9), produced the tetrasaccharide 10. Reiteration of deallylation and trichloroacetimidate formation from 10 yielded the tetrasaccharide donor 12. The downstream disaccharide acceptor 18 was obtained by condensation of 5 with methyl 3-O-acetyl-4,6-O-benzylidene-α-D-mannopyranoside, followed by debenzylidenation, benzoylation, and selective 3-O-deacetylation. Coupling of 18 with 12 afforded the hexasaccharide 19, and subsequent deprotection gave the hexasaccharide glycoside 20. Selective 2'-O-deacetylation of 19 gave the hexasaccharide acceptor 21. Condensation of 21 with glucopyranosyluronate imidate 22 did not produce the expected heptasaccharide glycoside; instead, a transacetylation product 19 was obtained. Meanwhile, there was no reaction between 21 and the bromide donor 23
glucuronic acid, Mannose, Xylose
Structure type: polymer chemical repeating unit
Location inside paper: Fig. 1D
Trivial name: glucuronoxylomannan (GXM)
Compound class: CPS, EPS, glucuronoxylomannan
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_423153,IEDB_76933,IEDB_983930,SB_197,SB_44,SB_67,SB_72
Synthetic data: chemical
Comments, role: model deacetylated structure; 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): 9240, 9353, 9354, 9355, 50826
NCBI Taxonomy refs (TaxIDs): 40410Reference(s) to other database(s): GTC:G53406VG, CCSD:
50379, CBank-STR:13359
Show glycosyltransferases
There is only one chemically distinct structure:
Found 
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(later renamed to: Cryptococcus neoformans var. neoformans)