Thio-sugars. IV: Design and synthesis of S-linked fucoside analogs as a new class of alpha-L-fucosidase inhibitors

Regioselective direct sulfenylation of glycals using arylsulfonyl chlorides in the presence of triphenylphosphine: access to C2-thioaryl glycosides

Cheap and easily available arylsulfonyl chlorides as a sulfur source reductively couple with glycals in the presence of triphenylphosphine to afford C2-thioaryl glycosides.

Convenient preparation of thioglycomimetics: S-glycosyl sulfenamides, sulfinamides and sulphonamides

S-Glycosyl sulfenamide derivatives were rapidly prepared from glycosyl thiols using N-bromosuccinimide or N-chlorosuccinimide. Sulfenamide derivatives were oxidized to corresponding sulfinamides and sulfonamides.

Tri-isopropylsilyl thioglycosides as masked glycosyl thiol nucleophiles for the synthesis of S-linked glycosides and glyco-conjugates

Tri-isopropylsilyl thio-glycosides (TIPS S-glycosides), readily synthesized from glycosyl halides, glycosyl acetates, or p-methoxyphenyl glycosides, were in one-pot de-silylated and S-alkylated, -acylated, or -glycosylated in high yields and short time.

Facile synthesis of sulfonium ion derivatives of 1,5-anhydro-5-thio-l-fucitol as potential α-l-fucosidase inhibitors

Five sulfonium ion derivatives with 1,5-anhydro-5-thio-L-fucitol as a core structure were efficiently synthesized as potential alpha-L-fucosidase inhibitors. The key unit, the tri-O-benzyl derivative of L-fucitol, was readily synthesized from methyl alpha-D-mannopyranoside. Alkylation with methyl iodide or 5-methoxycarbonyl-1-pentyl iodide in acetonitrile containing AgBF4 afforded the corresponding alkylated sulfonium tetrafluoroborates. Alternatively, ring opening of three 1,3-cyclic sulfates in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) containing K2CO3 afforded the corresponding zwitterionic sulfonium sulfates.

Spirocyclopropyl pyrrolidines as a new series of α-l-fucosidase inhibitors

Polyhydroxy 4-azaspiro[2.4]heptane derivatives (spirocyclopropyl iminosugars) were prepared in four to six steps from readily available protected aldoses. The key step of the reaction sequence involves a titanium-mediated aminocyclopropanation of glycononitriles with subsequent cyclization. Five new polyhydroxypyrrolidines so-obtained have been evaluated for their ability to inhibit 16 glycosidases. One of them exhibits selective inhibition of alpha-L-fucosidase from bovine kidney (Ki=1.6 microM, competitive).

Thio-sugars VII. Effect of 3-deoxy-4-S-(beta-D-gluco- and beta-D-galactopyranosyl)-4-thiodisaccharides and their sulfoxides and sulfones on the viability and growth of selected murine and human tumor cell lines

The first conversion of (1-->4)-thiodisaccharides into corresponding sulfoxides and sulfones by conventional oxidation with m-chloroperoxybenzoic acid (MCPBA) is reported. The effects of alpha-(1-->4)-3'-deoxythiodisaccharides (8-9) and their sulfoxide (14-15) and sulfone (16-17) derivatives on murine leukemia and human colon and pancreatic carcinoma cell viability were studied. Concentrations of thio-sugars that decreased tumor cell line viability by 50% (IC(50)), measured via the MTT assay, ranged from 6.4 to 38.3 microg/mL. The effect of alpha-(1-->4)-3'-deoxythiodisaccharide derivatives were most profound on human pancreatic epithelial carcinoma (PANC-1) cells with compounds 8 and 9 having IC(50) values of 6.4 microg/mL and 8.2 microg/mL, respectively. Sulfone derivatives 16 and 17 also had pronounced effects on PANC-1 cell viability (IC(50)=10.2 microg/mL and 9.6 microg/mL, respectively). These results indicate that deoxythio-disaccharide analogs generated by functionalization of the universal chiral precursor levoglucosenone may have cytotoxic properties and therapeutic potential as anticancer agents.

New leads for selective inhibitors of alpha-L-fucosidases. Synthesis and glycosidase inhibitory activities of [(2R,3S,4R)-3,4-dihydroxypyrrolidin-2-yl]furan derivatives

Readily derived from D-glucose, 5-[(2R,3S,4R)-3,4-dihydroxypyrrolidin-2-yl]-2-methyl-3-furoic esters and amides are selective and competitive inhibitors (K(i)> or = 3 microM) of alpha-L-fucosidase from bovine epididymis and from human placenta.