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Shimizu M, Brenner T, Liao R, Matsukawa S. Diffusion of probe polymer in gellan gum solutions during gelation process studied by gradient NMR. Food Hydrocoll 2012. [DOI: 10.1016/j.foodhyd.2011.04.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
A full assignment of high-field nmr spectra of gellan was obtained in dilute aqueous solution by performing a series of selective one-dimensional nmr experiments. The observed nuclear Overhauser effects (NOEs) cannot be interpreted assuming that each sugar residue is intrinsically rigid and in a chair conformation. In fact, the rhamnose residue gives strong NOE contacts coherent only with an equilibrium involving both a chair as well as a boat (or a hemiboat) conformation. Molecular dynamic calculations performed on a heptamer with a central rhamnose support the above finding, and show a structure based on a very stiff single chain in which it is present a flipping of the rhamnose residue. At low temperatures (5-20 degrees C) in very dilute solutions (0.018 mg/mL) nmr spectra show a splitting of the resonance due to the methyl group of rhamnose residue, thus confirming the presence of a slow equilibrium among different conformers.
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Affiliation(s)
- M Bosco
- Polytech, SCaRL AREA Science Park, Padriciano 99, I-34012 Trieste, Italy
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Rinaudo M, Milas M. Gellan gum, a bacterial gelling polymer. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s0167-4501(00)80012-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
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Jay A, Colquhoun I, Ridout M, Brownsey G, Morris V, Fialho A, Leitão J, Sá-Correia' I. Analysis of structure and function of gellans with different substitution patterns. Carbohydr Polym 1998. [DOI: 10.1016/s0144-8617(97)00241-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Gunning AP, Kirby AR, Ridout MJ, Brownsey GJ, Morris VJ. Investigation of Gellan Networks and Gels by Atomic Force Microscopy. Macromolecules 1996. [DOI: 10.1021/ma960700h] [Citation(s) in RCA: 107] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- A. P. Gunning
- Institute of Food Research, Norwich Laboratory, Norwich Research Park, Colney, Norwich NR4 7UA, U.K
| | - A. R. Kirby
- Institute of Food Research, Norwich Laboratory, Norwich Research Park, Colney, Norwich NR4 7UA, U.K
| | - M. J. Ridout
- Institute of Food Research, Norwich Laboratory, Norwich Research Park, Colney, Norwich NR4 7UA, U.K
| | - G. J. Brownsey
- Institute of Food Research, Norwich Laboratory, Norwich Research Park, Colney, Norwich NR4 7UA, U.K
| | - V. J. Morris
- Institute of Food Research, Norwich Laboratory, Norwich Research Park, Colney, Norwich NR4 7UA, U.K
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Deasy P, Quigley KJ. Rheological evaluation of deacetylated gellan gum (Gelrite) for pharmaceutical use. Int J Pharm 1991. [DOI: 10.1016/0378-5173(91)90034-l] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Cairns P, Miles M, Morris V. X-Ray fibre diffraction studies of members of the gellan family of polysaccharides. Carbohydr Polym 1991. [DOI: 10.1016/0144-8617(91)90002-t] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Abstract
Tetramethyl ammonium (TMA) gellan does not gel. Light scattering studies suggest that in solutions of TMA gellan, in tetramethyl ammonium chloride (TMACI), the gellan molecules assemble end to end to produce elongated fibrous structures. Such fibrils are envisaged as resulting from double-helix formation between the ends of neighbouring gellan molecules. Fibrils with molecular weights ranging from (1.06 +/- 0.06) x 10(5) to (4.5 +/- 0.1) x 10(6) have been observed. The molecular weights obtained depended upon the pore size of the filters used to clarify the solutions. The formation of strong gels, in the presence of gel promoting cations, is attributed to a localized ordered lateral association, or crystallization of regions of these fibrils. It is suggested that such a model for gelation may be of general applicability to a number of polysaccharide systems.
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Affiliation(s)
- A P Gunning
- AFRC Institute of Food Research, Norwich Laboratory, UK
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Shatwell KP, Sutherland IW, Ross-Murphy SB, Dea IC. Influence of the acetyl substituent on the interaction of xanthan with plant polysaccharides — I. Xanthan-locust bean gum systems. Carbohydr Polym 1990. [DOI: 10.1016/0144-8617(90)90005-d] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Crescenzi V, Dentini M. The influence of side-chains on the dilute-solution properties of three structurally related, bacterial anionic polysaccharides. Carbohydr Res 1987. [DOI: 10.1016/0008-6215(87)80318-x] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Morris V, Miles M. Effect of natural modifications on the functional properties of extracellular bacterial polysaccharides. Int J Biol Macromol 1986. [DOI: 10.1016/0141-8130(86)90053-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Crescenzi V, Dentini M, Coviello T, Rizzo R. Comparative analysis of the behavior of gellan gum (S-60) and welan gum (S-130) in dilute aqueous solution. Carbohydr Res 1986. [DOI: 10.1016/s0008-6215(00)90062-4] [Citation(s) in RCA: 68] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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O'Neill MA, Morris VJ, Selvendran RR, Sutherland IW, Taylor IT. Structure of the extracellular gelling polysaccharide produced by Enterobacter (NCIB 11870) species. Carbohydr Res 1986; 148:63-9. [PMID: 3708628 DOI: 10.1016/0008-6215(86)80037-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The gelling polysaccharide produced by a species of Enterobacter (NCIB 11870) contains L-fucose, D-glucose, and D-glucuronic acid in the ratios 1:2:1. Analysis of the methylated and methylated, carboxyl-reduced polysaccharide revealed terminal non-reducing glucose, (1----3)-linked fucose, (1----3,1----4)-linked glucose, and (1----4)-linked glucuronic acid in the ratios 1:1:1.2:0.8. From the results of Smith degradation of the polysaccharide and spectroscopic studies of the acidic tetra- and octa-saccharides produced by bacteriophage-induced enzymic depolymerization of the polysaccharide, the following tetrasaccharide repeating-unit is proposed. (Formula: see text). This repeating-unit is identical to that of the capsular polysaccharide produced by Klebsiella aerogenes serotype K54 except for the absence of O-acetyl groups. The effects of the O-acetyl groups on the secondary structure and rheological properties of these polysaccharides are discussed.
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X-Ray fibre diffraction results from Alcaligenes (ATCC 31555) microbial polysaccharide S-130 and a comparison with gellan gum. Carbohydr Res 1986. [DOI: 10.1016/0008-6215(86)80053-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Structure of the extracellular polysaccharide produced by the bacterium Alcaligenes (ATCC 31555) species. Carbohydr Res 1986. [DOI: 10.1016/s0008-6215(00)90638-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Brownsey G, Chilvers G, Anson K, Morris V. Some observations (or problems) on the characterization of gellan gum solutions. Int J Biol Macromol 1984. [DOI: 10.1016/0141-8130(84)90033-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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O'Neill MA, Selvendran RR, Morris VJ. Structure of the acidic extracellular gelling polysaccharide produced by Pseudomonas elodea. Carbohydr Res 1983. [DOI: 10.1016/0008-6215(83)88360-8] [Citation(s) in RCA: 165] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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