Showing papers on "Aldose published in 2013"

Docking Studies of Chlorogenic Acid against Aldose Redutcase by using Molgro Virtual Docker Software

Abstract: Docking studies of chlorogenic acid against aldose reductase, an enzyme involved in diabetic complications, have been performed, in order to evaluate the inhibitory effects of chlorogenic acid on this enzyme. The docking studies were performed using Molgro Virtual Docker (MVD) software. From the several available alternative methods to incorporate protein flexibility in docking studies, the use of multiple crystal structures with different bound ligands was applied here, thus, of the available crystal structures of the non- mutated aldose reductase enzyme from Homo sapiens, five were selected for the final docking studies. The docking results of chlorogenic acid with selected aldose reductase crystal structures shows that it forms hydrogen bonds with at least two out of three key active site residues (Tyr48, His110 and Trp111). It also form hydrogen bonds to other active site residues, in particular Thr113. The average MolDock score and the MolDock Re-rank score for cholorogenic acid are -119.34 Kcal/mol and -114.92 Kcal/mol respectively. The docking results show that chlorogenic acid fits well in the active site of aldose reductase and interact with the residues in the active site which are crucial for their biological activity, thus, it could a potent inhibitor of aldose reductase enzyme and thus be used for prevention/treatment of diabetic complications.

Optimized GC-MS method to simultaneously quantify acetylated aldose, ketose, and alditol for plant tissues based on derivatization in a methyl sulfoxide/1-methylimidazole system.

Abstract: The isomers of monosaccharide always produce multiple chromatographic peaks as volatile derivatives during gas chromatography, which may result in the overlapping of different sugar peaks Whereas reduction and oximation of sugar carbonyl groups for GC analysis do eliminate many isomer derivatives, the approaches create new problems One ketose can yield two peaks by oximation, and different aldoses and ketoses can yield the same alditol upon reduction, leading to the inability to detect some important monosaccharides This paper reports an optimal method that yields a single peak per sugar by acetylation directly By using a methyl sulfoxide (Me2SO)/1-methylimidazole (1-MeIm) system, the carbohydrates in acetic anhydride (Ac2O) esterification reactions were solubilized, and the oxidation that normally occurs was inhibited The results demonstrate that acetylated derivatives of 23 saccharides had unique peaks, which indicates aldose, ketose, and alditol can be determined simultaneously by GC-MS

Medicinal Flowers. XXXVIII. Structures of Acylated Sucroses and Inhibitory Effects of Constituents on Aldose Reducatase from the Flower Buds of Prunus mume

Abstract: The methanolic extract from the flower buds of Prunus mume, cultivated in Zhejiang province, China, showed an inhibitory effect on aldose reductase. From the methanolic extract, five new acylated sucroses, mumeoses F-J, were isolated together with 29 known compounds. The chemical structures of the new compounds were elucidated on the basis of chemical and physicochemical evidence. The inhibitory effects of the isolated compounds on aldose reductase were also investigated. Acylated quinic acid analogs, which are one of the major compounds of the flower buds of P. mume, were shown to substantially inhibit aldose reductase. In particular, mumeic acid-A was found to exhibit a potent inhibitory effect [IC50=0.4 µm].

Synthesis of Specially Designed Probes to Broaden Transketolase Scope

Abstract: Efficient, biocompatible, stereospecific strategies were developed to prepare eight probes to assay transketolase (TK) variants with new substrate specificities. The structure of these probes combines a sugar moiety (D-threo or L-erythro ketose, or D-threo aldose) with the side chain of an amino acid (Ala, Leu, Val, Met, Thr) for in vivo detection of new TK activities using amino acid auxotrophs. To obtain D-threo ketose probes, biocatalysts, such as transketolase and fructose-6-phosphate aldolase Ala129Ser, were used whereas L-erythro ketoses and D-threo aldose probes were synthesized by the way of organocatalysis or Sharpless dihydroxylation as sustainable alternative key steps to biocatalysis.

Method for preparing ketose by utilizing aldose

Abstract: The invention discloses a method for preparing ketose by utilizing aldose. The method for preparing ketose by utilizing aldose comprises the following steps of: in an organic solvent, carrying out isomerization reaction on aldose under the catalytic action of a molecular sieve based catalyst to obtain glucoside; and carrying out in-situ hydrolysis on the glucoside under the catalytic action of water and the molecular sieve based catalyst to obtain ketose. The invention provides a method for producing ketose by taking low-cost and high-efficiency aldose as a raw material. The method for preparing ketose by utilizing aldose has the advantages that reaction conditions are mild, activity is high, and recovery rates of the catalyst and the solvent are high; the amount of byproducts is low, and yield of a target product is 81%; a molecular sieve and alcohol are respectively taken as the catalyst and the solvent, and economic and environmental costs are low; a heterogeneous catalysis system is adopted, products and the catalyst can be easily separated, aftertreatment is simple, and industrialization is easy to realize.

Method for manufacturing 5-hydroxymethyl-2-furfural or its alkyl ether derivatives in organic solvents using ion exchange resins

Abstract: PURPOSE: A method for preparing 5-hydroxymethyl-2-furfural or an alkyl ether derivative thereof using ion exchange resin under the presence of an organic solvent is provided to enable easy isolation and purification, and to directly prepare chemically stable AMF(5-alkoxymethyl2-furfural). CONSTITUTION: A method for preparing a furan-based compound comprises: a step of reacting aldose type hexose compounds using an anion exchange resin by isomerization, and preparing ketose type hexose compounds; and a step of dehydrating the ketose type hexose compounds using a cation exchange resin.

Method for preparing ketose by utilizing aldose

Abstract: The invention discloses a method for preparing ketose by utilizing aldose. The method for preparing ketose by utilizing aldose comprises the following steps of: in an organic solvent, carrying out isomerization reaction on aldose under the catalytic action of a molecular sieve based catalyst to obtain glucoside; and carrying out in-situ hydrolysis on the glucoside under the catalytic action of water and the molecular sieve based catalyst to obtain ketose. The invention provides a method for producing ketose by taking low-cost and high-efficiency aldose as a raw material. The method for preparing ketose by utilizing aldose has the advantages that reaction conditions are mild, activity is high, and recovery rates of the catalyst and the solvent are high; the amount of byproducts is low, and yield of a target product is 81%; a molecular sieve and alcohol are respectively taken as the catalyst and the solvent, and economic and environmental costs are low; a heterogeneous catalysis system is adopted, products and the catalyst can be easily separated, aftertreatment is simple, and industrialization is easy to realize.