61474-17-7

Upstream product

• 10028-44-1 1,2,3,4-tetra-O-acetyl-6-O-triphenylmethyl-α-D-glucopyranose 
• 604-68-2 α-D-glucopyranose peracetylate 
• 83-87-4 D-glucose pentaacetate 
• 71208-20-3 1,2,3,4-tetra-O-acetyl-6-O-benzoyl-α-D-glucopyranose 
• 67919-36-2 1,2,3,4-tetra-O-acetyl-6-O-trityl-D-glucopyranoside 
• 492-62-6 alpha-D-glucopyranose 
• 108-24-7 acetic anhydride 
• 4163-60-4 β-D-galactose peracetate 
• 54325-28-9 (2R,3R,4S,5S,6R)-6-Trityloxymethyl-tetrahydro-pyran-2,3,4,5-tetraol 
• 54325-28-9 6-O-trityl-α-D-glucose 
• 2280-44-6 D-Glucose 

Downstream Products

• 71208-20-3 1,2,3,4-tetra-O-acetyl-6-O-benzoyl-α-D-glucopyranose 
• 1034191-98-4 C₂₁H₂₃NO₁₄ 

Relevant academic research and scientific papers

Highly efficient deacetylation by use of the neutral organotin catalyst [tBu2SnOH(Cl)]2

Deprotection of acetyl esters is effected cleanly by the neutral organotin catalyst, [tBu2SnOH(Cl)]2. The mildness of the reaction gives rise to great synthetic versatility and in the process a variety of functional groups are tolerated. Differentiations between primary, secondary, and tertiary alcohols and between acetyl ester and other esters are feasible. No racemization occurs with chiral acetyl esters. Exclusive deprotection of primary acetyl esters in carbohydrates and nucleosides is observed. The crude product thus obtained can be used for further reactions without purification.

Discriminating non-ylidic carbon-sulfur bond cleavages of sulfonium ylides for alkylation and arylation reactions

A sulfonium ylide participated alkylation and arylation under transition-metal free conditions is described. The disparate reaction pattern allowed the separate activation of non-ylidic S-alkyl and S-aryl bond. Under acidic conditions, sulfonium ylides serve as alkyl cation precursors which facilitate the alkylations. While under alkaline conditions, cleavage of non-ylidic S-aryl bond produces O-arylated compounds efficiently. The robustness of the protocols were established by the excellent compatibility of wide variety of substrates including carbohydrates.

Diastereoselective Synthesis of Thioglycosides via Pd-Catalyzed Allylic Rearrangement

Stereoselective glycosylation is challenging in carbohydrate chemistry. Herein, stereoselective thioglycosylation of glycals via palladium-catalyzed allylic rearrangement yields various substituents on α-isomer thioglycosides. Two comprehensive series of aryl and benzyl thioglycosides were obtained via a combination of thiosulfates with glycals derived from glucose, arabinose, galactose, and rhamnose. Furthermore, diosgenyl α-l-rhamnoside and isoquercitrin achieved selectivity via stereospecific [2,3]-sigma rearrangements of α-sulfoxide-rhamnoside and α-sulfoxide-glucoside, respectively.

Regio- A nd chemoselective deprotection of primary acetates by zirconium hydrides

A combination of DIBAL-H and Cp2ZrCl2 is shown to promote the regioselective cleavage of primary acetates on a broad scope of substrates, ranging from carbohydrates to terpene derivatives, with a high tolerance toward protecting groups and numerous functionalities found in natural products and bioactive compounds. Apart from providing highly valuable building blocks in only two steps from biosourced raw materials, this selective de-O-acetylation should also be strongly helpful to solve selectivity issues in organic synthesis.

Total synthesis of agalloside, isolated from: Aquilaria agallocha, by the 5-O-glycosylation of flavan

Agalloside (1) is a neural stem cell differentiation activator isolated from Aquilaria agallocha by our group using Hes1 immobilized beads. We conducted the first total synthesis of agalloside (1) via the 5-O-glycosylation of flavan 25 using glycosyl fluoride 20 in the presence of BF3·Et2O. Subsequent oxidation with DDQ to flavanone 2 and deprotection successively provided agalloside (1). This synthetic strategy holds promise for use in the synthesis of 5-O-glycosylated flavonoids. The synthesized agalloside (1) accelerated neural stem cell differentiation, which is a result comparable to that for the naturally occurring compound 1.

Biocatalytic Process Optimization for the Production of High-Added-Value 6-O-Hydroxy and 3-O-Hydroxy Glycosyl Building Blocks

A biocatalytic process to synthesize regioselective monohydroxy glycosyl building blocks has been optimized. Lipases immobilized on commercial supports were treated with water-soluble carbodiimide (EDC) at different concentrations. In the presence of cosolvents, the stability of lipases adsorbed on octyl-Sepharose improved after the EDC modification. The new Candida rugosa lipase (CRL) modified heterogeneous biocatalysts were tested in the production of 6-OH hydroxyl-tetraacetyl glucose by a regioselective mono-deacetylation in aqueous media. Improvements in activity and excellent regioselectivity were obtained for octyl-CRL-EDC10mM preparation, with 95 % isolated yield of product on a multimilligram scale. We also observed excellent recyclability. The C-6 alcohol was transformed to a C-3 alcohol by chemical migration, and both compounds were transformed successfully in the corresponding new trichloroacetimidyl glucoderivatives. Modified CRL biocatalysts were also tested in the selective deprotection of peracetylated thymidine, and octyl-CRL-EDC10mM showed excellent specificity and improved regioselectivity to produce 3-hydroxy-5-acetyl-thymidine, a precursor of azidethymidine (AZT), in 95 % yield. The new Rhizomucor miehei lipase (RML)-modified heterogeneous biocatalysts showed excellent regioselectivity and recyclability in the 3-OH mono-deprotection of peracetylated lactal.

Glycopolymer self-assemblies with gold(I) complexed to the core as a delivery system for auranofin

A new glycomonomer 1 containing a thioacetate group in the anomeric position and mimicking the thiosugar ligand of the gold-based drug auranofin was designed and synthesized in four steps from d-glucose. Both CPADB-mediated homopolymerization and chain extension of a hydrophilic poly(OEGMEMA) macroRAFT agent were well-controlled with dispersities (D) below 1.2, highlighting the suitability of thioacetate as a thiol protecting group in RAFT polymerization. Using the homopolymer as a test system, the thioacetate protective groups were selectively removed using hydrazine acetate, and AuPEt3Cl was subsequently complexed to the exposed thiols to generate a polymeric auranofin analogue with 52% complexation efficiency. Extension of this successful procedure to three block copolymers with differing hydrophobic block lengths, poly(OEGMEMA)34-b-poly(1)47, poly(F-OEGMEMA)32-b-poly(1)27, and poly(F-OEGMEMA)32-b-poly(1)7 (where F in the last two indicates the incorporation of 2 wt % fluorescein methacrylate into the hydrophilic block), produced well-defined complexed block copolymers with complexation efficiencies comparable to that of the homopolymer. Self-assembly of the longest complexed polymer poly(OEGMEMA)34-b-poly(1-AuPEt3)47 generated spherical micelles with a hydrodynamic diameter Dh of 28 nm when prepared by slow water addition to a dilute DMF solution. The IC50 value against OVCAR-3 cells in a serum-free media was 44 μM on a gold concentration basis, compared to 0.3 μM for auranofin itself. The two shorter fluorescent complexed block copolymers formed spherical micelles with Dh 23 and 9 nm, respectively, and proved more cytotoxic than their longer counterpart, both displaying IC50 values of 13.5 μM. The addition of serum to the cell growth medium reduced the cytotoxicity of auranofin by a factor of 3.6 but had a less marked effect on the fluorescent micellar systems, reducing their toxicities by between 2.4 and 2.8 times. These micellar systems therefore show less susceptibility to deactivation by serum proteins (which is the primary limitation to auranofins in vivo effectiveness) than the free auranofin, suggesting some protective benefit offered by the hydrophilic shell. Fluorescence microscopy of the two fluorescent systems revealed an accumulation in the lysosomes of the OVCAR-3 cells. The cytotoxicity mechanism may therefore differ from that of auranofin, which is known to interact with mitochondrial proteins.

Escherichia coli LacZ β-galactosidase inhibition by monohydroxy acetylated glycopyranosides: Role of the acetyl groups

Escherichia coli LacZ β-galactosidase is an extensively employed glycosidase for many different scientific purposes. Here, we describe how acetyl moieties protecting hydroxyl groups of the glycosides make these molecules better inhibitors to the enzyme activity. In particular, the presence of a unique hydroxyl group in the peracetylated glycosides still enhanced the inhibitory capacity of the molecule more. Molecular docking studies showed that the acetylation in the carbohydrate structure helps the substrate to accommodate into the active site. From a small biocatalytic synthesized library of different monohydroxy acetylated glycosides we can conclude that galactosidic structures are better for inhibition capacity. The best inhibitors were two monohydroxy lactal derivatives. The one with the OH free, in C-6 of the galactosidic part of the disaccharide, was a better inhibitor (Ki of 95 μM) than that with the OH free in C-3 in the glucosidic part of the molecule (Ki of 143 μM).

METHODS, COMPOUNDS, COMPOSITIONS AND VEHICLES FOR DELIVERING 3-AMINO-1-PROPANESULFONIC ACID

The invention relates to methods, compounds, compositions and vehicles for delivering 3-amino-1-propanesulfonic acid (3APS) in a subject, preferably a human subject. The invention encompasses compounds that will yield or generate 3APS, either in vitro or in vivo. Preferred compounds include amino acid prodrugs of 3APS for use, including but not limited to, the prevention and treatment of Alzheimer's disease.

Regioselective hydrolysis of different peracetylated β-monosaccharides by immobilized lipases from different sources. Key role of the immobilization

The effect of the immobilization strategy on the activity, specificity and regioselectivity of three different lipases [those from Thermomyces lanuginose (TLL), Aspergillus niger (ANL) and Candida antarctica B (CAL-B)] in the hydrolysis of peracetylated β-monosaccharides has been evaluated. Three very different immobilization strategies were utilized, covalent attachment, anionic exchange and interfacial activation on a hydrophobic support. The octyl-TLL immobilized preparation was the most efficient biocatalyst in the hydrolysis of 1,2,3,4,6-pentaO-acetyl-β-D-galactopyranose, producing specifically 6-hydroxy-l,2,3,4-tetra-O-acetyl-β-D-galactopyranose in 95 % overall yield, whereas the CNBr-TLL preparation was 48 times slower and regioselective towards the anomeric position, producing the 1-hydroxy derivative in 70% yield. The PEI-TLL immobilized preparation was the most efficient catalyzing the hydrolysis of 1,2,3,4,6-penta-O-acetyl-β-D-glucopyranose, permitting us to obtain up to 70% of the 6-hydroxy product. In the hydrolysis of 2-acetamido2-deoxy-l,3,4,6-tetra-0-acetyl-β-D-glucopyranose, the octyl-CALB preparation was not selective at all for the production of monohydroxy products whereas when CAL-B was immobilized on PEI-agarose, the enzyme was highly specific and regioselective producing the 6-hydroxy-2- acetamido-2-deoxy-l,3,4-tri-O-acetyl-β-D-glucopyranose in 70 % yield.