29024-90-6

Upstream product

• 7512-17-6 N-Acetyl-D-glucosamine 
• 53-84-9 nicotinamide adenine dinucleotide 
• 14131-68-1 N-acetyl-D-glucosamine 
• 72-87-7 N-acetyl-D-mannosamine 
• 24960-16-5 N-acetylmannosaminolactone 
• 72-87-7 N-acetyl-D-galactosamine 

Relevant academic research and scientific papers

D - production of glucosamine acid or its analogs, as well as catalyst composition

PROBLEM TO BE SOLVED: To provide a means for simply and efficiently producing D-glucosamic acid or its analogue.SOLUTION: By using a catalyst composition including a carrier comprising hydrotalcite, magnesium oxide or calcium oxide and gold particles carried on the carrier, it becomes possible to produce D-glucosamic acid or its analogue simply and efficiently from corresponding D-glucosamine or its analogue.

Crystal structures and functional studies clarify substrate selectivity and catalytic residues for the unique orphan enzyme N-acetyl-D-mannosamine dehydrogenase

NAMDH (N-acetyl-D-mannosamine dehydrogenase), from the soil bacteroidete Flavobacterium sp. 141-8, catalyses a rare NAD+ -dependent oxidation of ManNAc (N-acetyl-Dmannosamine) into N-acetylmannosamino-lactone, which spontaneously hydrolyses into N-acetylmannosaminic acid. NAMDH belongs to the SDR (short-chain dehydrogenase/reductase) superfamily and is the only NAMDH characterized to date. Thorough functional, stability, site-directed mutagenesis and crystallographic studies have been carried out to understand better the structural and biochemical aspects of this unique enzyme. NAMDH exhibited a remarkable alkaline pH optimum (pH 9.4) with a high thermal stability in glycine buffer (Tm =64°C) and a strict selectivity towards ManNAc and NAD+ . Crystal structures of ligand-free and ManNAc- and NAD + -bound enzyme forms revealed a compact homotetramer having point 222 symmetry, formed by subunits presenting the characteristic SDR α3β7α3 sandwich fold. A highly developed C-terminal tail used as a latch connecting nearby subunits stabilizes the tetramer. A dense network of polar interactions with the substrate including the encasement of its acetamido group in a specific binding pocket and the hydrogen binding of the sugar 4OH atom ensure specificity for ManNAc. The NAMDH-substrate complexes and site-directed mutagenesis studies identify the catalytic tetrad and provide useful traits for identifying new NAMDH sequences.

Synthesis of α-amino acids from glucosamine-HCl and its derivatives by aerobic oxidation in water catalyzed by au nanoparticles on basic supports

The golden wonder: Various α-amino acids such as glucosaminic acid, galactosaminic acid, or N-acetyl-glucosaminic acid can be obtained from the corresponding glucosamine derivatives (amino sugars). This is achieved through an aqueous oxidation that cataly

Substrate specificity of galactokinase from Streptococcus pneumoniae TIGR4 towards galactose, glucose, and their derivatives

Galactokinases (GalKs) have attracted significant research attention for their potential applications in the enzymatic synthesis of unique sugar phosphates. The galactokinase (GalKSpe4) cloned from Streptococcus pneumoniae TIGR4 presents a remarkably broad substrate range including 14 diverse natural and unnatural sugars. TLC and MS studies revealed that GalKSpe4 had relaxed activity towards galactose derivatives with modifications on the C-6, 4- or 2-positions. Additionally, GalKSpe4 can also tolerate glucose while glucose derivatives with modifications on the C-6, 4- or 2-positions were unacceptable. More interestingly, GalKSpe4 can phosphorylate l-mannose in moderate yield (43%), while other l-sugars such as l-Gal cannot be recognized by this enzyme. These results are very significant because there is rarely enzyme reported that can phosphorylate such uncommon substrates as l-mannose.

The reaction of hyaluronic acid and its monomers, glucuronic acid and N- acetylglucosamine, with reactive oxygen species

Synovial fluid is a ~0.15% (w/v) aqueous solution of hyaluronic acid (HA), a polysaccharide consisting of alternating units of GlcA and GlcNAc. In synovial fluid of patients suffering from rheumatoid arthritis, HA is thought to be degraded either by radicals generated by Fenton chemistry (Fe2+/H2O2) or by NaOCl generated by myeloperoxidase. We investigated the course of model reactions of these two reactants in physiological buffer with HA, and with the corresponding monomers GlcA and GlcNAc. meso-Tartaric acid, arabinuronic acid, arabinaric acid and glucaric acid were identified by GC-MS as oxidation products of glucuronic acid. When GlcNAc was oxidised, erythronic acid, arabinonic acid, 2-acetamido-2-deoxy-gluconic acid, glyceric acid, erythrose and arabinose were formed. NaOCl oxidation of HA yielded meso-tartaric acid; in addition, arabinaric acid and glucaric acid were obtained by oxidation with Fe2+/H2O2. These results indicate that oxidative degradation of HA proceeds primarily at glucuronic acid residues. meso-Tartaric acid may be a useful biomarker of hyaluronate oxidation since it is produced by both NaOCl and Fenton chemistry.

Purification and Characterization of N-Acetyl-D-hexosamine Dehydrogenase from Pseudomonas sp. No. 53

A new enzyme, N-acetyl-D-hexosamine dehydrogenase (N-acetyl-α-D-hexosamine: NAD+ 1-oxidoreductase), was purified to homogeneity on polyacrylamide gel electrophoresis from a strain of Pseudomonas sp. about 900-fold with a yield of 12percent.The molecular weight of the enzyme was about 124,000 on gel filtration and 30,000 on SDS-polyacrylamide gel electrophoresis, respectively.Its isoelectric point was 4.7.The optimum pH was about 10.0.The enzyme was most stable between pH 8.0 and pH 10.5.The highest enzyme activity was observed with N-acetyl-D-glucosamine (Km=5.3 mM) and N-acetyl-D-galactosamine (Km=0.8 mM) as the sugar substrate.But it was not so active on N-acetyl-D-mannosamine.NAD+ was used specifically as the hydrogen acceptor.The anomeric requirement of the enzyme for N-acetyl-D-glucosamine was the α-pyranose form, and the reaction product was N-acetyl-D-glucosaminic acid.The enzyme activity was inhibited by Hg2+ and SDS, but many divalent cations, metal-chelating reagents, and sulfhydryl reagents had no effect.