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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.


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Journal ArticleDOI
TL;DR: In this article, the cocondensation of atomic carbon with water at 77 K generates a mixture of straight chain aldoses with up to five carbons, and a proposed mechanism involves initial reaction of C with H 2 O to give hydroxymethylene which rearranges to formaldehyde.
Abstract: The cocondensation of atomic carbon with water at 77 K generates a mixture of straight chain aldoses with up to five carbons. A proposed mechanism involves initial reaction of C with H 2 O to give hydroxymethylene which rearranges to formaldehyde. Subsequent nucleophilic addition of hydroxymethylene to formaldehyde with hydrogen transfer generates glycolaldehyde which reacts with additional hydroxymethylenes to build up the higher carbohydrates. Confirmation of this mechanism is provided by deuterium labeling studies

35 citations

Journal ArticleDOI
TL;DR: In this paper, the seven-coordinated cage-type cobalt-II complexes containing N-glycosides from mannose-type aldoses and tris(2-aminoethyl)amine (tren), where (aldose)3tren is tris (2-(aldosylamino)ethyl)amines, were prepared and characterized by elemental analysis, electronic absorption and circular dichroism spectroscopies, and X-ray crystallography.
Abstract: Novel seven-coordinated cage-type cobalt(II) complexes containing N-glycosides from mannose-type aldoses and tris(2-aminoethyl)amine (tren), [Co((aldose)3tren)]X2·nH2O (1a·5H2O, aldose = d-mannose (d-Man), X = Cl-; 1b·5H2O, aldose = 6-deoxy-l-mannose (l-Rha), X = Cl-; 2a·4H2O, aldose = d-Man, X = Br-; 2b·H2O, aldose = l-Rha, X = Br-) and [Co((aldose)3tren)]SO4·nH2O (3a·4H2O, aldose = d-Man; 3b·3H2O, aldose = l-Rha), where (aldose)3tren is tris(2-(aldosylamino)ethyl)amine, were prepared and characterized by elemental analysis, electronic absorption and circular dichroism spectroscopies, and X-ray crystallography. Crystal data are as follows. 2b·2CH3OH: C26H56N4O14Br2Co, monoclinic, space group P21, a = 11.045(2) A, b = 17.283(6) A, c = 10.996(3) A, β = 117.371(6)°, V = 1864(1) A3, Z = 2, R = 0.072 for 2787 independent reflections. 3b·3H2O·CH3OH: C25H58N4O20SCo, orthorhombic, space group P212121, a = 14.836(2) A, b = 22.489(2) A, c = 12.181(3) A, V = 4064(1) A3, Z = 4, R = 0.077 for 2010 independent refle...

35 citations

Book ChapterDOI
TL;DR: This chapter provides an overview of the chemistry of anhydro sugars, which are heteromorphic sugar derivatives that formally arise by the elimination of one or more water molecules from arbitrary hydroxyl groups of the parent aldose or ketose.
Abstract: Publisher Summary This chapter provides an overview of the chemistry of anhydro sugars. Anhydro sugars, also called “intramolecular anhydrides,” are heteromorphic sugar derivatives that formally arise by the elimination of one or more water molecules from arbitrary hydroxyl groups of the parent aldose or ketose. They usually contain a bicyclic or tricyclic skeleton composed of oxirane, oxetane, oxolane (tetrahydrofuran), and oxane (tetrahydropyran) rings. If the hemiacetal group is involved in the formation of such a ring, the resulting glycose anhydride exhibits properties approaching ordinary glycosides. In general, the reactivity of anhydro sugars is determined mostly by the size of the oxygen rings. Oxirane and oxetane rings show a high reactivity, whereas oxolane and oxane rings are less reactive. However, the position of the anhydro bond, the steric arrangement, and the conformation of the molecule also play a significant role. Nowadays, anhydro sugars constitute very versatile starting materials not only in carbohydrate chemistry but also for the synthesis of noncarbohydrate and nonnatural compounds. In the past two decades, the interest in anhydro sugars has increased because they have been shown to be suitable monomers for preparing stereoregular polysaccharides and their specifically substituted derivatives.

34 citations

Journal ArticleDOI
TL;DR: Cell-free extracts of Bacillus subtilis contain enzyme activities which catalyze an acyloin-type condensation reaction (carboligase reaction) resulting in the formation of 1-deoxy-ketoses, a precursor of biosynthesis of thiazole ring of thiamine.
Abstract: Cell-free extracts of Bacillus subtilis contain enzyme activities which catalyze an acyloin-type condensation reaction (carboligase reaction) resulting in the formation of 1-deoxy-ketoses. The reactions are deduced to proceed as follows: pyruvate + aldose →C02 + 1-deoxy-ketose (I)acetoin + aldose →acetaldehyde + 1-deoxy-ketose (II)methylacetoin + aldose →acetone + 1-deoxy-ketose (III)Experiments with mutants of B. subtilis defective in pyruvate dehydrogenase (PDH) or acetoin dehydrogenase (AccDH) and with partially purified enzyme preparations revealed that PDH (EC 1.2.4.1) catalyzes reaction (I), and AccDH catalyzes reactions (II) and (III).That the PDH purified from Escherichia coli and the PDC purified from bovine heart also catalyzed reaction (I) indicates that 1-deoxy-ketose-forming activities are widely distributed. One of the reactions catalyzed by these enzymes is the formation of 1-deoxy-d-threo-pentulose, a precursor of biosynthesis of thiazole ring of thiamine.

34 citations

Journal ArticleDOI
TL;DR: It appears that aldose reductase may constitute a major detoxification route of these toxic aldehydes in the retina.

34 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20233
20226
20213
20207
20196
201813