4429-06-5

Upstream product

• 3913-65-3 2-hydroxypropanal 
• 96-26-4 dihydroxyacetone 
• 92418-41-2 L-Fuculose-1-phosphate 
• 38088-18-5 1-deoxy-L-psicose 
• 73804-38-3 1-deoxy-L-altritol 
• 2438-80-4 L-Fucose 
• 110-86-1 pyridine 
• 488-69-7 fructose-1,6-bisphosphate 

Downstream Products

• 7658-10-8 6-Deoxy-L-talose 
• 99881-06-8 D-arabino-6-deoxy-[2]hexosulose-bis-phenylhydrazone 

Relevant academic research and scientific papers

Characterization of a novel D-arabinose isomerase from Thermanaeromonas toyohensis and its application for the production of D-ribulose and L-fuculose

D-Ribulose and L-fuculose are potentially valuable rare sugars useful for anticancer and antiviral drugs in the agriculture and medicine industries. These rare sugars are usually produced by chemical methods, which are generally expensive, complicated and do not meet the increasing demands. Furthermore, the isomerization of D-arabinose and L-fucose byDD-arabinose and L-fucose by D-arabinose isomerase from bacterial sources for the production of D-ribulose and L-fuculose have not yet become industrial due to the shortage of biocatalysts, resulting in poor yield and high cost of production. In this study, a thermostable D-ribulose- and L-fuculose producing D-arabinose isomerase from the bacterium Thermanaeromonas toyohensis was characterized. The recombinant D-arabinose isomerase from T. toyohensis (Thto-DaIase) was purified with a single band at 66 kDa using His-trap affinity chromatography. The native enzyme existed as a homotetramer with a molecular weight of 310 kDa, and the specific activities for both D-arabinose and L-fucose were observed to be 98.08 and 85.52 U mg?1, respectively. The thermostable recombinant Thto-DaIase was activated when 1 mM Mn2+ was added to the reactions at an optimum pH of 9.0 at 75 °C and showed approximately 50% activity for both D-arabinose and L-fucose at 75 °C after 10 h. The Michaelis-Menten constant (Km), the turnover number (kcat) and catalytic efficiency (kcat/Km) for D-arabinose/L-fucose were 111/81.24 mM, 18,466/10,688 min?1, and 166/132 mM?1 min?1, respectively. When the reaction reached to equilibrium, the conversion rates of D-ribulose from D-arabinose and L-fuculose from L-fucose were almost 27% (21 g L?1) and 24.88% (19.92 g L?1) from 80 g L?1 of D-arabinose and L-fucose, respectively.

Efficient enzymatic synthesis of l-rhamnulose and l-fuculose

l-Rhamnulose (6-deoxy-l-arabino-2-hexulose) and l-fuculose (6-deoxy-l-lyxo-2-hexulose) were prepared from l-rhamnose and l-fucose by a two-step strategy. In the first reaction step, isomerization of l-rhamnose to l-rhamnulose, or l-fucose to l-fuculose was combined with a targeted phosphorylation reaction catalyzed by l-rhamnulose kinase (RhaB). The by-products (ATP and ADP) were selectively removed by silver nitrate precipitation method. In the second step, the phosphate group was hydrolyzed to produce l-rhamnulose or l-fuculose with purity exceeding 99% in more than 80% yield (gram scale).

Molecular characterization of a thermostable l-fucose isomerase from Dictyoglomus turgidum that isomerizes l-fucose and d-arabinose

A recombinant thermostable l-fucose isomerase from Dictyoglomus turgidum was purified with a specific activity of 93 U/mg by heat treatment and His-trap affinity chromatography. The native enzyme existed as a 410 kDa hexamer. The maximum activity for l-fucose isomerization was observed at pH 7.0 and 80 °C with a half-life of 5 h in the presence of 1 mM Mn2+ that was present one molecular per monomer. The isomerization activity of the enzyme with aldose substrates was highest for l-fucose (with a kcat of 15,500 min-1 and a Km of 72 mM), followed by d-arabinose, d-altrose, and l-galactose. The 15 putative active-site residues within 5 A of the substrate l-fucose in the homology model were individually replaced with other amino acids. The analysis of metal-binding capacities of these alanine-substituted variants revealed that Glu349, Asp373, and His539 were metal-binding residues, and His539 was the most influential residue for metal binding. The activities of all variants at 349 and 373 positions except for a dramatically decreased kcat of D373A were completely abolished, suggesting that Glu349 and Asp373 were catalytic residues. Alanine substitutions at Val131, Met197, Ile199, Gln314, Ser405, Tyr451, and Asn538 resulted in substantial increases in Km, suggesting that these amino acids are substrate-binding residues. Alanine substitutions at Arg30, Trp102, Asn404, Phe452, and Trp510 resulted in decreases in kcat, but had little effect on Km.

DEOXYKETOHEXOSE ISOMERASE AND METHOD FOR PRODUCING DEOXYHEXOSE AND DERIVATIVE THEREOF USING SAME

Providing 1- or 6-deoxy products corresponding to all of aldohexoses, ketohexoses and sugar alcohols, as based on Deoxy-Izumoring, as well as a method for systematically producing those products. A method for producing deoxyketohexose and a derivative thereof using a deoxyketohexose isomerase derived from Pseudomonas cichorii ST-24 (FERM BP-2736), comprising epimerizing 1-deoxy D-ketohexose or 6-deoxy D-ketohexose or 1-deoxy L-ketohexose or 6-deoxy L-ketohexose at position 3 to produce the individually corresponding 1-deoxy D-ketohexose or 6-deoxy D-ketohexose or 1-deoxy L-ketohexose or 6-deoxy L-ketohexose as an intended product.

Conversion of l-rhamnose into ten of the sixteen 1- and 6-deoxyketohexoses in water with three reagents: d-tagatose-3-epimerase equilibrates C3 epimers of deoxyketoses

The efficient isomerization of l-rhamnose [the only cheaply available deoxy hexose] to 1-deoxy-l-psicose, 1-deoxy-d-psicose, 1-deoxy-l-fructose, 1-deoxy-d-fructose, 1-deoxy-l-tagatose, 6-deoxy-l-psicose, 6-deoxy-d-psicose, 6-deoxy-l-fructose, 6-deoxy-d-fructose, and 6-deoxy-l-tagatose is described. The conversion of rhamnose to ten of the sixteen 1- and 6-deoxyketohexoses is accomplished in water in three steps. The range of substrates for d-tagatose-3-epimerase (DTE) is extended to 1- and 6-deoxyketoses. An authentic sample of 6-deoxy-d-psicose is prepared from d-psicose.

Borate as a phosphate ester mimic in aldolase-catalyzed reactions: Practical synthesis of L-fructose and L-iminocyclitols

Dihydroxyacetone phosphate (DHAP)-dependent aldolases have been widely used for the organic synthesis of unnatural sugars or derivatives. The practicality of using DHAP-dependent aldolases is limited by their strict substrate specificity and the high cost and instability of DHAP. Here we report that the DHAP-dependent aldolase L-rhamnulose 1-phosphate aldolase (RhaD) accepts dihydroxyacetone (DHA) as a donor substrate in the presence of borate buffer, presumably by reversible in situ formation of DHA borate ester. The reaction appears to be irreversible, with the products thermodynamically trapped as borate complexes. We have applied this discovery to develop a practical one-step synthesis of the non-caloric sweetener L-fructose. L-Fructose was synthesized from racemic glyceraldehyde and DHA in the presence of RhaD and borate in 92% yield on a gram scale. We also synthesized a series of L-iminocyclitols, which are potential glycosidase inhibitors, in only two steps.

ENZYMATIC ALDOL REACTION/ISOMERIZATION AS A ROUTE TO UNUSUAL SUGARS

Utilizing fructose diphosphate aldolase and glucose isomerase as catalysts, 3-, 5-, and 6-deoxy- and 6-O-methylhexoses have been synthesized from dihydroxyacetone phosphate or acetol phosphate and the corresponding hydroxypropionaldehydes.