title: Positional isomers of thioxylobiose, their synthesis and inducing ability for D-xylan-degrading enzymes in the yeast Cryptococcus albidus.
abstract: Isomeric S-linked 2-thioxylobiose 10, 3-thioxylobiose 17, and 4-thioxylobiose 19 were conveniently prepared by SN2 displacement of suitable triflylglycoses with the sodium salt of 2,3,4-tri-O-acetyl-1-thio-beta-D-glucopyranose, either in N,N-dimethylformamide, or in oxolan in the presence of a sodium complexing agent. Allyl 3,5-O-isopropylidene-2-O-trifluoromethanesulfonyl-beta-D-lyxofu ranoside was a convenient electrophilic precursor for 10, which was smoothly obtained after a short sequence of deprotection involving conversion to the 1-propenyl glycoside. 1,2:5,6-Di-O-isopropylidene-3-O-trifluoromethylsulfonyl-alpha-D-++ +allofuranose and 1,2,3-tri-O-benzoyl-4-O-trifluoromethylsulfonyl-beta-L-arabinop yranose were the respective precursors for 17 and 19. 4-Thioxylobiose has a highly stimulatory effect on the synthesis of enzymes of the xylanolytic system in the yeast Cryptococcus albidus when applied to the cells in the presence of the natural disaccharide inducer (1----4)-beta-D-xylobiose.
authors.affiliation: Département de Recherche Fondamentale, Centre d'Etudes Nucléaires de Grenoble, France.
authors.forename: J
authors.initials: J
authors.lastname: Defaye
authors.forename: J M
authors.initials: JM
authors.lastname: Guillot
authors.forename: P
authors.initials: P
authors.lastname: Biely
authors.forename: M
authors.initials: M
authors.lastname: Vrsanská
mesh_terms: D002240:Carbohydrate Sequence; D003454:Cryptococcus / Q000201:enzymology*; D004187:Disaccharides / Q000138:chemical synthesis / Q000494:pharmacology*; D004790:Enzyme Induction / Q000187:drug effects; D005656:Fungal Proteins; D006026:Glycoside Hydrolases / Q000187:drug effects / Q000378:metabolism; D006027:Glycosides / Q000378:metabolism*; D007536:Isomerism; D026901:Membrane Transport Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D043325:Xylan Endo-1,3-beta-Xylosidase; D014990:Xylans / Q000378:metabolism; D014995:Xylosidases / Q000187:drug effects / Q000378:metabolism
chemical_list: D004187:Disaccharides; D005656:Fungal Proteins; D006027:Glycosides; D026901:Membrane Transport Proteins; D014990:Xylans; C010807:xylosides; C028552:beta-xyloside permease, Cryptococcus albidus; C076314:4-thioxylobiose; D006026:Glycoside Hydrolases; D014995:Xylosidases; D043325:Xylan Endo-1,3-beta-Xylosidase