13224-95-8

Upstream product

• 582-52-5 1,2:5,6-di-O-isopropylidene-α-D-glucofuranose 
• 2847-00-9 1,2:5,6-di-O-isopropylidene-α-D-hexofuran-3-ulose 
• 14686-89-6 (1,2:5,6)-di-O-isopropylidene-D-gulose 
• 29587-01-7 5-[2,2-dimethyl-(4R)-1,3-dioxolan-4-yl]-2,2-dimethyl-(3aR,5R,6R,6aR)-perhydrofuro[2,3-d][1,3]dioxol-6-yl methyl ether 
• 54649-66-0 1,2:5,6-di-O-isopropylidene-α-D-gulose 
• 97834-06-5 (3aR,5R,6S,6aR)-5-((S)-2,2-dimethyl-1,3-dioxolan-4-yl)-6-methoxy-2,2-dimethyltetrahydrofuro[2,3-d][1,3]-dioxol 
• 38-26-6 holothurin A 

Downstream Products

• 126874-18-8 (S,S)-1,2:4,6-di-O-benzylidene-3-O-methyl-α-D-gulose 
• 126797-42-0 (S)-4,6-O-benzylidene-3-O-methyl-D-gulose 

Relevant academic research and scientific papers

Systematic Hydrogen-Bond Manipulations To Establish Polysaccharide Structure–Property Correlations

A dense hydrogen-bond network is responsible for the mechanical and structural properties of polysaccharides. Random derivatization alters the properties of the bulk material by disrupting the hydrogen bonds, but obstructs detailed structure–function correlations. We have prepared well-defined unnatural oligosaccharides including methylated, deoxygenated, deoxyfluorinated, as well as carboxymethylated cellulose and chitin analogues with full control over the degree and pattern of substitution. Molecular dynamics simulations and crystallographic analysis show how distinct hydrogen-bond modifications drastically affect the solubility, aggregation behavior, and crystallinity of carbohydrate materials. This systematic approach to establishing detailed structure–property correlations will guide the synthesis of novel, tailor-made carbohydrate materials.

A sulfated galactan with antioxidant capacity from the green variant of tetrasporic Gigartina skottsbergii (Gigartinales, Rhodophyta)

The water soluble polysaccharide produced by the green variant of tetrasporic Gigartina skottsbergii was found to be composed of d-galactose and sulfate groups in a molar ratio of 1.0:0.65. 1H and 13C NMR spectroscopy studies of the desulfated polysaccharide showed a major backbone structure of alternating 3-linked β-d-galactopyranosyl and 4-linked α-d-galactopyranosyl units, and minor signals ascribed to 3-O-methyl-substitution on the latter unit. Ethylation analysis of the polysaccharide indicated that the sulfate groups are mainly located at position O-2 of 4-linked α-d-galactopyranosyl residue and partially located at positions O-6 of the same unit and at position O-2 of 3-linked β-d-galactopyranosyl residue, and confirmed the presence of 3-O-methyl-galactose in minor amounts (4.4%). The sulfated d-galactan presents a similar structure to λ carrageenan but with much lower sulfation at position O-6 of the α-residue and at position O-2 of β-residue. The antioxidant capacity of the sulfated d-galactan was evaluated by the peroxyl radicals (ORAC method), hydroxyl radicals, chelating activity, and ABTS + assays. Kinetic results obtained in these assays were compared with those obtained for the commercial λ carrageenan. The antioxidant activity toward peroxyl radicals was higher for commercial λ carrageenan, this agrees with its higher content of sulfate group. The kinetics of the reaction of both polysaccharides with hydroxyl and ABTS+ radicals showed a complex mechanism, but the antioxidant activity was higher for the polysaccharide from the green variant of tetrasporic Gigartina skottsbergii.

The Synthesis and Reactivity of Cyclic Thiocarbonates Derived from Some Carbohydrate 1,2-Diols

The attempted synthesis of several carbohydrate 1,2-diols is reported, together with the transformation of two of these diols into cyclic thiocarbonates, namely 4,6-O-benzylidene-3-O-methyl-1,2-O-thiocarbonyl-α-D-glucose and 3,4-O-isopropylidene-1,2-O-thiocarbonyl-β-D-arabinose.The treatment of these thiocarbonates, and a furanose 1,2-thiocarbonate previously prepared by Mukaiyama, with methyl halides and with tributyltin hydride is discussed.A single-crystal X-ray diffraction study of 3,4-O-isopropylidene-1,2-O)-thiocarbonyl-β-D-arabinose is recorded.

The galactan sulphate of the red alga Polysiphonia lanosa.

The structure of the galactan sulphate of P. lanosa has been established by a combination of methylation, treatment with alkali, and partial methanolysis of the alkali-treated polysaccharide to give derivatives of agarobiose. The polysaccharide belongs to the agar class, in which 3-linked derivatives of beta-D-galactose alternate with 4-linked derivatives of alpha-L-galactose in a repeating sequence. In addition to D-galactose itself, the 3-linked units include 6-O-methyl-D-galactose, D-galactose 6-sulphate, and a hitherto unreported unit, 6-O-methyl-D-galactose 4-sulphate. The 4-linked units include L-galactose 6-sulphate, 2-O-methyl-L-galactose 6-sulphate, and 3,6-anhydro-L-galactose.