Showing papers on "Aldose published in 2014"

Inhibitory effects of Colocasia esculenta (L.) Schott constituents on aldose reductase.

Abstract: The goal of this study was to determine the rat lens aldose reductase-inhibitory effects of 95% ethanol extracts from the leaves of C. esculenta and, its organic solvent soluble fractions, including the dichloromethane (CH2Cl2), ethyl acetate (EtOAc), n-butanol (BuOH) and water (H2O) layers, using dl-glyceraldehyde as a substrate. Ten compounds, namely tryptophan (1), orientin (2), isoorientin (3), vitexin (4), isovitexin (5), luteolin-7-O-glucoside (6), luteolin-7-O-rutinoside (7), rosmarinic acid (8), 1-O-feruloyl-d-glucoside (9) and 1-O-caffeoyl-d-glucoside (10) were isolated from the EtOAc and BuOH fractions of C. esculenta. The structures of compounds 1–10 were elucidated by spectroscopic methods and comparison with previous reports. All the isolates were subjected to an in vitro bioassay to evaluate their inhibitory activity against rat lens aldose reductase. Among tested compounds, compounds 2 and 3 significantly inhibited rat lens aldose reductase, with IC50 values of 1.65 and 1.92 μM, respectively. Notably, the inhibitory activity of orientin was 3.9 times greater than that of the positive control, quercetin (4.12 μM). However, the isolated compounds showed only moderate ABTS+ [2,29-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)] activity. These results suggest that flavonoid derivatives from Colocasia esculenta (L.) Schott represent potential compounds for the prevention and/or treatment of diabetic complications.

Enzymatic production of three 6-deoxy-aldohexoses from l-rhamnose

Abstract: 6-Deoxy-L-glucose, 6-deoxy-L-altrose, and 6-deoxy-L-allose were produced from L-rhamnose with an immobilized enzyme that was partially purified (IE) and an immobilized Escherichia coli recombinant treated with toluene (TT). 6-Deoxy-L-psicose was produced from L-rhamnose by a combination of L-rhamnose isomerase (TT-PsLRhI) and D-tagatose 3-epimerase (TT-PcDTE). The purified 6-deoxy-L-psicose was isomerized to 6-deoxy-L-altrose and 6-deoxy-L-allose with L-arabinose isomerase (TT-EaLAI) and L-ribose isomerase (TT-AcLRI), respectively, and then was epimerized to L-rhamnulose with immobilized D-tagatose 3-epimerase (IE-PcDTE). Following purification, L-rhamnulose was converted to 6-deoxy-L-glucose with D-arabinose isomerase (TT-BpDAI). The equilibrium ratios of 6-deoxy-L-psicose:6-deoxy-L-altrose, 6-deoxy-L-psicose:6-deoxy-L-allose, and L-rhamnulose:6-deoxy-L-glucose were 60:40, 40:60, and 27:73, respectively. The production yields of 6-deoxy-L-glucose, 6-deoxy-L-altrose, and 6-deoxy-L-allose from L-rhamnose were 5.4, 14.6, and 25.1%, respectively. These results indicate that the aldose isomerases used in this study acted on 6-deoxy aldohexoses.

Double-triazole conjugated false disaccharide derivative and preparation method thereof

Abstract: The invention discloses a double-triazole conjugated false disaccharide derivative shown as the general formula (I), wherein P represents a protecting group/unprotecting group of a hydroxyl or an amidogen or represents a hydrogen atom; when the P represents the protecting group, the protection mode can be complete protection or partial protection; R represents a side-chain group on a methine for connecting two triazole groups in a fragment B; the methine is keyed on 2-bit N of one triazole and 1-bit N of the other triazole; a fragment A and a fragment C are glucosides of a five-element or six-element single aldose; anomeric carbon is of Alpha-type or Beta-type or Alpha/Beta-mixed-type structure; the types of the glucosides of the fragment A and the fragment C are same or different; and n represents 2, 3 or 4. The derivative contains mother nucleus structures of the triazoles and has the functions of bacterium and virus resistance.

Structural Characterization and Functional Validation of Aldose Reductase from the Resurrection Plant Xerophyta viscosa

Abstract: Aldose reductases are key enzymes in the detoxification of reactive aldehyde compounds like methylglyoxal (MG) and malondialdehyde. The present study describes for first time the preliminary biochemical and structural characterization of the aldose reductase (ALDRXV4) enzyme from the resurrection plant Xerophyta viscosa. The ALDRXV4 cDNA was expressed in E. coli using pET28a expression vector, and the protein was purified using affinity chromatography. The recombinant protein showed a molecular mass of ~36 kDa. The K M (1.2 mM) and k cat (14.5 s−1) of the protein determined using MG as substrate was found to be comparable with other reported homologs. Three-dimensional structure prediction based on homology modeling suggested several similarities with the other aldose reductases reported from plants. Circular dichroism spectroscopy results supported the bioinformatic prediction of alpha–beta helix nature of aldose reductase proteins. Subcellular localization studies revealed that the ALDRXV4-GFP fusion protein was localized both in the nucleus and the cytoplasm. The E. coli cells overexpressing ALDRXV4 exhibited improved growth and showed tolerance against diverse abiotic stresses induced by high salt (500 mM NaCl), osmoticum (10 % PEG 6000), heavy metal (20 mM CdCl2), and MG (5 mM). Based on these results, we propose that ALDRXV4 gene from X. viscosa could be a potential candidate for developing stress-tolerant crop plants.

Compositions and methods for treating colon cancer

Abstract: Certain embodiments are directed to methods of treating a pathophysiological state or symptoms thereof resulting from aldose reductase-mediated signaling in a cytotoxic pathway using an aldose reductase specific inhibitor.

Biosynthesis method of 2-deoxy scarce aldose by using aldolase

Abstract: The invention relates to a biosynthesis method of 2-deoxy scarce aldose such as 2-deoxy-D-ribose aldolase by using aldolase, and discloses protein sequences of two 2-deoxy-D-ribose 5-phosphate aldolase mutants, and a constructed Escherichia coli recombinant bacterial strain L1 containing encoding genes of the 2-deoxy-D-ribose 5-phosphate aldolase mutants Experiments show that the recombinant strain can catalyze reaction of acetaldehyde and a variety of aldehyde groups to produce 2-deoxy aldose by using resting cells, and has strong substrate tolerance For example, recombinant strain can synthesize 2-deoxy-D-ribose by using aldehyde and D-glyceraldehyde as substrates, synthesize 2-deoxy-L-ribose by using acetaldehyde and L-glyceraldehyde as substrates, and synthesize 2-deoxy-D-altrose by using acetaldehyde and D-erythrose as substrates Therefore, the Escherichia coli recombinant bacterial strain L1 provided by the invention can be applied to the production of deoxidation deoxy scarce aldose, and the obtained deoxy aldose has wide application prospect in the industries of food and medicine

Double-triazole conjugated false disaccharide derivative and preparation method thereof

Abstract: The invention discloses a double-triazole conjugated false disaccharide derivative shown as the general formula (I), wherein P represents a protecting group/unprotecting group of a hydroxyl or an amidogen or represents a hydrogen atom; when the P represents the protecting group, the protection mode can be complete protection or partial protection; R represents a side-chain group on a methine for connecting two triazole groups in a fragment B; the methine is keyed on 2-bit N of one triazole and 1-bit N of the other triazole; a fragment A and a fragment C are glucosides of a five-element or six-element single aldose; anomeric carbon is of Alpha-type or Beta-type or Alpha/Beta-mixed-type structure; the types of the glucosides of the fragment A and the fragment C are same or different; and n represents 2, 3 or 4. The derivative contains mother nucleus structures of the triazoles and has the functions of bacterium and virus resistance.

New osazone diagram for determination of two aldoses and a ketose that form identical osazone

Abstract: A new and interesting osazone diagram was presented for determination and identification of a pair aldoses and a ketose that makes the same osazone This chart facilitated the finding any aldose and/or ketose yielded the same osazone

2d qsar studies on the differential inhibition of aldose reductase by flavoniods compounds: a comparative study

Abstract: A quantitative structure activity relationship study of 66 molecules was performed using MLR(Multiple Linear Regression) and PCR (Principal component Analysis) of aldose reductase by flavonoids compounds.Various descriptors, topological indices were used to characterize flavonoids molecules.In the developed model MLR is giving vary significant results wheras PCR has revealed some important information. Keywords: Flavonoids, aldose reuctase, QSAR, Multiple Linear Regression, Principle Component Regression

Synthesis of deoxyamino sugars

Abstract: The invention relates to methods for making an α-amino-aldehyde, preferably a 2-amino-2-deoxy sugar derivative, from an α-hydroxy-aldehyde, preferably an aldose. Intermediary 1-amino-1-deoxy-ketose derivatives, and their use as synthetic intermediates, are also described.