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.

Characterization of aldose reductases Ia and Ib from rabbit lens.

Abstract: The properties of two aldose reductases (Ia and Ib) from rabbit lens were investigated. Both enzymes showed similar substrate specificity, and were capable of reducing various aldoses and aldehydes. On the basis of apparent Km, Vmax and second-order rate constant (kcat/Km) values, both enzymes had the highest reductive efficiency toward aromatic aldehydes such as pnitrobenzaldehyde. Among the aldoses tested, the aldose reductases exhibited a high affinity for DL-glyceraldehyde (Km of 31μM for Ia and 32μM for Ib) and a low affinity for D-glucose (Km of 92mM for Ia and 126mM for Ib). Aldose reductase I's could utilize both reduced nicotinamide adenine dinucleotide phosphate (NADPH) and reduced nicotinamide adenine dinucleotide (NADH) as coenzymes, but NADH was less effective than NADPH. The Km values for NADPH (1.4μM for Ia and 1.3μM for Ib) were much smaller than those for NADH (420μM for Ia and 270μM for Ib). Aldose reductase I's were strongly activated by sulfate ion and their Km and Vmax values for substrate and coenzyme were increased. Aldose reductase I's were inhibited strongly by aldose reductase inhibitors : about 80% by 0.3μM quercitrin, 65% by 1.6μM quercetin and about 70% by 8.0μM 3, 3-tetramethyleneglutaric acid. NADP+ and adenosine 2', 5'-diphosphate (2', 5'-ADP) were strong competitive inhibitors of both aldose reductase I's with respect to the coenzyme. The K1 values for 2', 5'-ADP were about 30μM, and those for NADP+ were about 70μM.

Intramolecular C-arylation of benzylated sugars. The unexpected double C-glycosideration of tris-O-m-methoxybenzyl-β-D-ribofuranose derivatives

Abstract: Upon treatment with tin(IV) chloride, D-ribofuranose derivatives bearing activated O-benzyl groups were found to undergo single or double intramolecular C-arylation, with m-methyl- and m-methoxy-substituted benzyl groups respectively.

Direct Oxidative Amidation of Aldoses by Iodine in Ammonia Water

Abstract: Aldopentoses, aldohexoses and the benzylated derivatives reacted with iodine in ammonia water at room temperature to give their corresponding saccharide amides in high yields. The reactions proceeded with oxidation of the aldose hemiacetals by iodine to generate the saccharide lactone intermediates, which underwent ammonolysis in situ to give the saccharide amides.

5-substituted alkylidene-2- (N-cyanoimino) thiazolidin-4-one derivatives, their preparation and their use as aldose reductase inhibitors

Abstract: A class of compounds represented by the formula (I) wherein R₁s are the same or different groups and each represents hydrogen atom or alkyl group having 1 to 4 carbon atoms; R₂ is phenyl group, naphthyl group, or either phenyl or naphthyl substituted with at least one hydroxyl, alkyl having 1 to 4 carbon atoms or alkoxy having 1 to 4 carbon atoms; R₃ is hydrogen atom, alkyl group having 1 to 4 carbon atoms or CH₂COOR₄ group, in which R₄ is hydrogen atom or alkyl group having 1 to 12 carbon atoms; n is 0 or 1, the configuration of 5-methylene group includes both E-isomer and Z-isomer, providing excepting the case wherein R₁ is hydrogen atom, R₂ is 3,5-di-t-butyl-4-hydroxyphenyl, R₃ is hydrogen atom and n is 0 or pharmacologically acceptable salts thereof when R₃ or R₄ is hydrogen atom. The invention also concerns preparation methods thereof. The present compounds are useful as prophylactic or therapeutic agents for neuropathy, retinopathy, diabetic cataract, impediment in the kidney as tubulo-nephrosis, all known as complications of chronic diabetes and especially aldose reducing enzyme induced complications.