Showing papers on "Aldose published in 2005"

Structure of aldehyde reductase holoenzyme in complex with the potent aldose reductase inhibitor fidarestat: implications for inhibitor binding and selectivity.

Abstract: Structure determination of porcine aldehyde reductase holoenzyme in complex with the potent aldose reductase inhibitor fidarestat was carried out to explain the difference in the potency of the inhibitor for aldose and aldehyde reductases. The hydrogen bonds between the active-site residues Tyr50, His113, and Trp114 and fidarestat are conserved in the two enzymes. In aldose reductase, Leu300 forms a hydrogen bond through its main-chain nitrogen atom with the exocyclic amide group of the inhibitor, which when replaced with a Pro in aldehyde reductase, cannot form a hydrogen bond, thus causing a loss in binding energy. Furthermore, in aldehyde reductase, the side chain of Trp220 occupies a disordered split conformation that is not observed in aldose reductase. Molecular modeling and inhibitory activity measurements suggest that the difference in the interaction between the side chain of Trp220 and fidarestat may contribute to the difference in the binding of the inhibitor to the enzymes.

Factorizing selectivity determinants of inhibitor binding toward aldose and aldehyde reductases: structural and thermodynamic properties of the aldose reductase mutant Leu300Pro-fidarestat complex.

Abstract: Structure of the Leu300Pro mutant of human aldose reductase (ALR2) in complex with the inhibitor fidarestat is determined. Comparison with the hALR2−fidarestat complex and the porcine aldehyde reductase (ALR1)−fidarestat complex indicates that the hydrogen bond between the Leu300 amino group of the wild-type and the exocyclic amide group of the inhibitor is the key determinant for the specificity of fidarestat for ALR2 over ALR1. Thermodynamic data also suggest an enthalpic contribution as the predominant difference in the binding energy between the aldose reductase mutant and the wild-type. An additional selectivity-determining feature is the difference in the interaction between the inhibitor and the side chain of Trp219, ordered in the present structure but disordered (corresponding Trp220) in the ALR1−fidarestat complex. Thus, the hydrogen bond (∼7 kJ/mol) corresponds to a 23-fold difference in inhibitor potency while the differences in the interactions between Trp219(ALR2) and fidarestat and between ...

Immunodetection of aldose reductase in normal and diseased human liver

Abstract: Aldose reductase is an NADPH-dependent aldo-keto reductase best known as the rate-limiting enzyme of the polyol pathway that is implicated in the complications of diabetes. Aldose reductase appears to be involved in a variety of disease states other than diabetes, presumably due to its ability to catalyze the reduction of a broad spectrum of aldehydes, including some cytotoxic products of lipid peroxidation. Although the data regarding expression of aldose reductase in normal liver are conflicting, prior studies have suggested that the enzyme may be induced in diseased liver. The goal of these studies was to characterize expression of aldose reductase in normal and diseased human liver, using RT-PCR, Western analysis and immunohistochemistry. Aldose reductase transcripts and protein were detected at low levels in control human livers. In contrast, levels of aldose reductase mRNA and protein were increased in chronically diseased human livers. Immunohistochemistry demonstrated localization of aldose reductase in sinusoidal lining cells; dual immunofluorescence confocal microscopy with the macrophage marker, CD68, confirmed that the aldose reductase-positive sinusoidal lining cells were Kupffer cells. Abundant aldose reductase-positive, CD68-positive cells were present in the fibrous septa of cirrhotic livers, accounting for the increase in immunoreactive aldose reductase in diseased livers. Immunostaining of human lung, spleen and lymph node revealed that macrophages in those tissues also express aldose reductase. These data are the first to demonstrate that aldose reductase is expressed by human macrophages in various tissues and suggest that this enzyme may play a role in immune or inflammatory processes.

Synthesis of ovalicin starting from D-mannose

Abstract: A new synthesis of epoxyketone 22 is described that is a key intermediate in Barton's synthesis of ovalicin (2), a powerful anti-angiogenetic inhibitor. The key process for the construction of 22 was ring-closing metathesis of olefins 11 and 12 obtained from 2,3:5,6-di-O-isopropylidene-α-d-mannofuranose (4) and regioselective desilylation of tri-TES ether 19. Furthermore, an alternative stereoselective route from 22 into 2 has also been developed, and the overall yield of 2 from 4 was 10.0%.

Method of producing aldonic acids and aldose dehydrogenase

Abstract: Aldonic acids are efficiently produced by coupling a reaction of oxidizing aldose by aldose dehydrogenase using nicotinamide adenine dinucleotide (NAD+) as a coenzyme with a NAD+ regeneration system using NADH oxidase. Also, it is intended to provide a recombinant microorganism in which NADH oxidase and aldonic acid dehydrogenase are expressed in a single host; an aldose dehydrogenase using NAD as a coenzyme; and a composition containing NADH oxidase. Thus, aldonic acids, which have been widely used in food additives, feed additives, medicinal additives and so on, can be efficiently produced by a convenient method.

Process for producing carbon-diminished aldose compound

Abstract: The present invention provides a process capable of industrially producing 5-deoxy-L-arabinose, important as a raw material for the production of sapropterin useful as a therapeutic agent for atypical hyperphenylalaninemia, satisfactorily efficiently even with a simple production apparatus. Provided is the process for producing 5-deoxy-L-arabinose characterized by including: reacting L-rhamnose with a C 11-16 straight chain alkyl mercaptan compound in the presence of an acid catalyst to prepare L-rhamnose dialkylmercaptal; subjecting then the obtained compound to an oxidation reaction to prepare a sulfonyl derivative; and subjecting then the sulfonyl derivative to a carbon-reduction reaction to prepare 5-deoxy-L-arabinose. The present production process can also be applied to a process for producing compounds obtained by removing one carbon atom from other aldol compounds, and thus the present invention provides a general process for producing compounds obtained by reducing the number of carbon atoms from aldose compounds.

Preparation of ketose sugars by isomerization of aldose sugars in the presence of potassium aluminate, useful as low calorie-type sweeteners

Abstract: Preparation of ketose sugars in which a solution or suspension of the aldose sugar is reacted with potassium aluminate to effect an isomerization. The mixture obtained is acidified by treatment with sulfuric acid to give a potassium/aluminum sulfate which can be separated by filtration. ACTIVITY : Antimicrobial. MECHANISM OF ACTION : None given.

Aldose reduction enzyme inhibitor

Abstract: PROBLEM TO BE SOLVED: To obtain a superior aldose reduction enzyme inhibitor, and also to provide a safe food composition or a medicinal composition derived from natural edible plants and ingestible over a long period of time without side effect SOLUTION: The aldose reduction enzyme inhibitor of the invention for solving the above-mentioned problem is characterised by containing solvent extracts of seeds of Oensothera tetraptera, seeds of Litchi chinensis, and black rice COPYRIGHT: (C)2007,JPO&INPIT

The Exploration of Question about Bormine Water Distinguish Glucose and Fructose

Abstract: The conditional,product and mechanism of Bormine Water oxidating Aldose and Ketose are discussed in this paper.The results show: in the acid solution which pH is 2～3,Bormina Water can distinguish Glucose and Fructose;in the nearly neutral solution which pH is 5～6 and in the Alkalescence solution which pH is 9～10.Bormina Water can not distinguish Glucose and Fructose;Further more the best distinguishing method is given.

Method for producing aldose

Abstract: PROBLEM TO BE SOLVED: To provide an industrial method for inexpensively and safely producing aldose in high yield by subjecting aldonic acid to decarboxylation reaction to produce a corresponding aldose as being accompanied by decrease of one carbon atom. SOLUTION: In the process for producing aldose from aldonic acid by using hypochlorous acid or a hypochlorite salt as one of carbon atoms is decreased, a compound having higher reactivity to the hypochlorous acid or its salt than that of the reaction product (namely aldose of which one carbon number is decreased) is added to the reaction mixture. COPYRIGHT: (C)2005,JPO&NCIPI