Sporothrix schenckii polysaccharide

Fig. 19.—13C-N.m.r. Spectra (Excluding C-CH3 Regions) of Polysaccharides (in D20) Isolated from Various Strains of Sporothrix schenckii. (Polysaccharides A, B, C, and D were isolated from Strains 1099.23, 1099.27, 1099.16, and 1099.18, respectively solvent, D2Oj temperature, 70° chemical shifts expressed as Sc, relative to external tetra-methylsilane.)...

In dimorphic fungi, the composition of constituent polysaccharides is sensitive to morphology and to the cultural conditions. These effects are accentuated in the case of Sporothrix schenckii, and 13C-n.m.r. spectroscopy can be used to detect individual polysaccharides in a qualitative way. The 13C-n.m.r. spectra of mannose-containing polysaccharides of ten Sporothrix schenckii and three Ceratocystis stenoceras species, grown under various conditions, were distinguishable in terms of the presence of signals,130 at 8C 103.3 to 103.7, which arose from 0-a-L-rhamnopyranosyl-(l- 2)-0-a-L-rhamnopyranosyl-(1— 3)-side-chains (14 C-l, 103.7 C-l, 96.8), and were not present in... 

Fig. 24.—13C-N.m.r. Spectrum of a Galactofuranose-Containing Polysaccharide from Sporothrix schenckii Grown on a Medium Containing Brain-Heart Infusion. (Solvent, DsO temperature, 70° chemical shifts expressed as 8C, relative to external tetramethyl-silane.)...

Methylation of a polysaccharide containing 2-amino-2-deoxy-D-galactose (88 %), protein (6.8 %), and phosphate (4.7 %) has indicated a linear structure of (1 — 4)-linked amino-sugar residues. An L-rhamno-D-mannan containing single unit a-L-rhamnopyranosyl side chains has been identified in isolated conidia of Sporothrix schenckii and differs from the di-L-rhamnosyl-D-mannan synthesized by the hyphae. ... 

The preferential synthesis of different polysaccharides by specific morphological types of Sporothrix schenckii has been reported. Thus, yeasts synthesize rhamnomannans containing monorhamnosyl side-chains, conidia or conidia-forming mycelia synthesize rhamnomannans with dirhamnosyl side-chains, and unsporulated mycelia synthesize galactomannans or mannans that are readily excreted into the culture medium. A combination of methylation analysis. Smith degradation, and n.m.r. spectroscopy was used to deduce the structure (25) for the D-mannan core of S. schenckii galactomannan. 

On the basis of the n.m.r. spectra, various structural assignments have been made to polysaccharides of S. schenkii, including a neutral mono-L-rhamnosyl-D-mannan and an acidic L-rhamno-D-mannan. Many strains from species of Sporothrix, Ceratocystis, Europhium, and Graphium have exhibited serological cross-reactions with S. schenckii, and contain polysaccharides composed of residues of L-rhamnose and D-mannose. The d-galacto-D-mannan of Schizosaccharomyces pombe has been located at the periphery of the cell wall and near the plasmalemma. No evidence was obtained for the presence of chitin. 

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