Formation of Inter-residue Hemiacetals During the Oxidation of Polysaccharides by Periodate Ion.

Ishak, Mona Fahmy; Painter, Terence; Andersen, V. Sten; Enzell, Curt R.; Lousberg, R. J. J. C.; Weiß, U.

doi:10.3891/acta.chem.scand.25-3875

Cited by 56 publications

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“…Hydrolysis of the last two polyalcohols failed to reveal the presence of Dglucose. The results are readily interpreted in the light of work by Painter and colleagues (14,15). These authors have shown that in polysaccharides containing 1,4-linkages inter-residue hemiacetal linkages niay be formed readily.…”

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confidence: 51%

The Structure of the Capsular Polysaccharide of Klebsiella K-type 5

Choy¹,

Dutton²

1973

Can. J. Chem.

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Methylation, periodate oxidation and partial hydrolysis studies on the capsular polysaccharide, and on the carboxyl reduced polymer of Klebsiella K5 show the structure to consist of a repeating unit:The polysaccharide has a molecular weight (by gel filtration) of 9 x loS and is the first Klebsiella capsule to be found lacking a carbohydrate side chain. The proportion of 0-acetyl and pyruvate groups was determined by p.m.r. spectroscopy.Les mithodes de methylation, oxydation periodique, et hydrolyse partielle portees au polysaccharide capsulaire, et au polymkre avec le groupe carboxyle reduit, de Klebsiella K5 ont demontri que la structure se compose d'une unite qui se rCpCte.Le polyoside posskde un poids molCculaire (par chromatographie sur gel) de 9 x lo5 et cette capsule de Klebsiella est la premiere d'etre trouvee sans une chaine laterale de sucre. Le rapport entre les groupes 0-acityles, pyruviques et sucres a kt6 dose par spectroscopie r.m.n.Can. J. Chem., 51. 1826 (1973) Bacteria of the genus Klebsiella elaborate a capsular polysaccharide which is antigenic. Approxiinately 80 different serotypes are recognized and Nimmich (1, 2) has provided qualitative analyses of these capsular materials. In continuation of our studies (3,4) on the structure of these polysaccharides we now report on the capsule from Klebsiella K-type 5. This polysaccharide differs from those previously described in this genus by lacking any carbohydrate side chain. The polysaccharide is also unusual in affording the first example of a 4,6-0-(1-carboxyethy1idene)-D-mannose unit in a natural product. This aspect of the structure has been discussed briefly (5).The crude polysaccharide from Klebsiella K5 (E5051) was extremely viscous and it was convenient to purify the material by centrifugation and precipitation with Cetavlon only in small batches. Purified material migrated as a single band on electrophoresis on cellulose acetate and had [a], -45.2", an equivalent weight of 233, and a n~olecular weight, by gel filtration, of 9 x 10'. Acid hydrolysis of the polysaccharide gave D-glucose, D-mannose, D-gl~icurone, and acidic components. The first two compounds were identified as their crystalline alditol hexaacetates and found to be Dresent in the ratio of 3: 5. When a portion of the hydrolyzate was saponified to hydrolyze any lactone, reduced, rehydrolyzed, and processed to avoid contamination of the neutral sugars by lactones, D-glucose and D-mannose were found in the ratio of 1 : 1. In the case of a sample of the polysaccharide which was methanolyzed, the uronic ester was reduced and the product was hydrolyzed to give D-glucose and D-mannose in the ratio of 2: 1.The glucose and mannose were shown to be of D-configuration by the circular dichroism (c. For personal use only.

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confidence: 51%

The Structure of the Capsular Polysaccharide of Klebsiella K-type 5

Choy¹,

Dutton²

1973

Can. J. Chem.

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“…This finding suggests that an oxidised unit of cellulose might protect the corresponding hydroxyl groups of an adjacent cellulose chain by a transient hemiacetal/acetal structure in equilibrium with the free-aldehyde form (Painter and Larsen 1970;Ishak and Painter 1971;Guthrie 1975;Veelaert et al 1994). Up to about 30 -40% of oxidation there are enough unoxidised couples of cellulose units to allow a relatively fast rate of oxidation, but thereafter the transient hemiacetal/acetal protection of the remaining C2 -C3 hydroxyl groups might cause the observed kinetic decrease.…”

Section: Discussionmentioning

confidence: 66%

Viscometric determination of dialdehyde content in periodate oxycellulose Part II. Topochemistry of oxidation

et al. 2006

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The kinetics of periodate oxidation of cellulose was followed through the alkaline degradation of the dialdehyde groups by measuring the viscometric degree of polymerisation and the alkali consumption. The obtained results show that a fast but limited attack of periodate occurs in the amorphous region of cellulose, causing the decrease of degree of polymerisation to its levelling-off value. The alkali consumption indicates at least two further slower reactions, that lead to the asymptotic complete oxidation of cellulose units. With the pseudo first-order approximation, the oxidation half-time of these three reactions can be calculated, corresponding to 1.2, 20 and 854 h respectively. In spite of the high oxidation of the analysed samples (up to about 46%), the residue after alkaline degradation shows a relatively high value of degree of polymerisation rather than the narrow molecular weight distribution of oligomers expected from a random oxidation, thus indicating that periodate oxidises cellulose in isolated domains. The sequence of analyses over the same sample utilised in this work (titrimetry, weight loss and viscometry), performed at room temperature in mild conditions, makes it possible to investigate the topochemistry of oxidation of paper and textiles of historic and artistic value with microdistructive techniques on a single, very small fragment of material.Abbreviations: a -fractional weight loss; DAU -dialdehyde units; DP -viscosity average degree of polymerisation (with suffixes ac -acidity degraded samples; hmw -high molecular weight fraction; lmw -low molecular weight fraction; ox -oxidised samples; oxred -oxidised and reduced samples); S -number of b-alkoxy scissions; t 0.5 -oxidation half-time

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“…Synthesized di-aldehyde is not stable to be isolated in di-aldehyde structure. This oxidized state forms hemiacetal with closest hydroxyl group and hemialdals with aldehyde inter-molecularly [27,32] carbinolamine. The later can eliminate hydroxide ion, which is assisted by nitrogen lone pair.…”

Section: Synthesis and Characterization Of Bis-quaternary Starchmentioning

confidence: 98%