Aldose

About: Aldose is a research topic. Over the lifetime, 1270 publications have been published within this topic receiving 27197 citations. The topic is also known as: aldoses.

Novel Poly(ionic liquid) Augmented Membranes for Unconventional Aqueous Phase Applications in Fractionation of Dyes and Sugar.

Abstract: Poly(ionic) liquid (PIL) augmented membranes were fabricated through self-polymerization of 2-vinyl pyridine and 4-vinyl pyridine followed by dopamine triggered polymerization and bridging with inert polyamide support. The resulting membranes acquired a positive surface charge with a high degree of hydrophilicity. Fourier transformed Infra-red (FTIR) and Energy dispersive X-ray (EDX) spectroscopic investigation revealed the successful augmentation of PIL surface layer, whereas surface morphology was investigated through scanning electron microscopy (SEM) imaging. This manuscript demonstrates pi electron-induced separation of dyes with the trend in permeability: Coomassie Brilliant Blue G (CBBHG) > Remazol Brilliant Blue R (RBBR) > Eichrome Black T (EBT) > Congo Red (CR). CBBG exhibited extended conjugation over large aromatic domain. RBBR and EBT were associated withtheelectron-donating -NH2 group and electron-withdrawing -NO2 group, respectively, hence pi electron density on aromatic ring varied. The steric repulsion between two pairs of ortho hydrogens (Hs) in biphenyl moieties of CR resulted in deviation of planarity and hence aromaticity leading to the lowest permeability. The sugar fractionation followed the trend: Galactose > Mannose > Fructose > Glucose > Xylose. More hydroxyl (-OH) groups in sugars and their conformational alignment in the same direction, exhibited more lone pair of electrons leading to more interaction with PIL and hence better permeability. Pentose showed poorer permeation than hexose, whereas aldose showed better permeation than ketose.

Aldose reductase inhibitor

Abstract: PURPOSE: To obtain the subject inhibitor giving a stable aqueous solution exhibiting excellent aldose reductase-inhibiting activity and a low toxicity with high solubility in water, containing sulfate derivatives of a compound having phenolic hydroxyl group as an active ingredient. CONSTITUTION: A sulfate derivative or salt thereof of a compound having phenolic hydroxyl group is contained in the objective drug having aldose reductase- inhibiting property comparable to or higher than a compound having not sulfuric esterified phenolic hydroxyl group as an active ingredient. As the compound having phenolic hydroxyl group, compounds extracted from various plants, such as tannic acid, pentagalloyl glucose expressed by formula I (G is galloyl group, namely 3,4,5-trihydroxybenzoyl expressed by formula II), rutin expressed by formula III, quercetin expressed by formula IV, ellagic acid expressed by formula V or epicatechin expressed by formula VI, are exemplified. Said drug is useful as therapeutic agent of various complications in diabetes mellitus such as cataract, retinopathy, kidney disease or nerve disturbance. COPYRIGHT: (C)1991,JPO&Japio

The mechanism of a one-substrate transketolase reaction.

Abstract: Transketolase catalyzes the transfer of a glycolaldehyde residue from ketose (the donor substrate) to aldose (the acceptor substrate). In the absence of aldose, transketolase catalyzes a one-substrate reaction that involves only ketose. The mechanism of this reaction is unknown. Here, we show that hydroxypyruvate serves as a substrate for the one-substrate reaction and, as well as with the xylulose-5-phosphate, the reaction product is erythrulose rather than glycolaldehyde. The amount of erythrulose released into the medium is equimolar to a double amount of the transformed substrate. This could only be the case if the glycol aldehyde formed by conversion of the first ketose molecule (the product of the first half reaction) remains bound to the enzyme, waiting for condensation with the second molecule of glycol aldehyde. Using mass spectrometry of catalytic intermediates and their subsequent fragmentation, we show here that interaction of the holotransketolase with hydroxypyruvate results in the equiprobable binding of the active glycolaldehyde to the thiazole ring of thiamine diphosphate and to the amino group of its aminopyrimidine ring. We also show that these two loci can accommodate simultaneously two glycolaldehyde molecules. It explains well their condensation without release into the medium, which we have shown earlier.