S-Linked Thiomimetics of Phytoalexin-Elicitor-Active, Branched Oligosaccharides, Their Synthesis, Protein-Binding Ability and Phytoalexin-Inducing Activity

Synthetic Routes to Thiooligosaccharides and Thioglycopeptides

“…The concentrations resulting in phytoalexin production at the 50% level (EC 50 value) were much higher than those of the O -glycosides giving a similar response in the bioassay. Thiooligosaccharides having a higher elicitor activity were also more efficient competitors of binding of the radiolabeled HG-APEA to the membrane-localized β-glucan binding sites of soybean …”

“…The sulfur-linked pentathiohexasaccharide 3 I ,3 IV -di-β- d -glucopyranosylthiogentiotetraose 119 has been synthesized in 83% yield by a convergent approach involving the reaction of iodo compound 118 with 1-thiosugar 117 in the presence of NaH at room temperature (Scheme ). ,

35

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“…The sulfur-linked pentathiohexasaccharide 3 I ,3 IV -di-β-Dglucopyranosylthiogentiotetraose 119 has been synthesized in 83% yield by a convergent approach involving the reaction of iodo compound 118 with 1-thiosugar 117 in the presence of NaH at room temperature (Scheme 35). 43,44 The product 119 was further converted to compound 120 in four steps. Some other thio-linked oligosaccharides were also synthesized in high yields by employing this convergent approach.…”

“…Thiooligosaccharides having a higher elicitor activity were also more efficient competitors of binding of the radiolabeled HG-APEA to the membrane-localized β-glucan binding sites of soybean. 44…”

Stereoselective Synthesis of β-Glycosyl Thiols and Their Synthetic Applications

“…Glycosyl thiol derivatives or 1-thiosugar derivatives are important building blocks for the synthesis of various thiooligosaccharides and glycoconjugate derivatives. − Because of the exceptional stability of the sulfide linkages toward the enzymatic hydrolysis, thiolinked glycoconjugates are considered as promising molecules to design therapeutics . The anomeric configuration of the glycosyl thiol derivatives mostly remains unaffected , during the course of synthetic transformations in contrast to its normal sugar hemiacetal derivatives.…”