Equilibrium Spatial Distribution of Aqueous Pullulan: Small-Angle X-ray Scattering and Realistic Computer Modeling
| Autor: | David A. Brant, Mitsuru Mimura, Shinichi Kitamura, Kanji Kajiwara, Jennifer H.-Y. Liu |
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| Rok vydání: | 1999 |
| Předmět: |
Aqueous solution
Polymers and Plastics Chemistry Small-angle X-ray scattering Scattering Organic Chemistry Solvation Pullulan Molecular physics Force field (chemistry) Inorganic Chemistry symbols.namesake chemistry.chemical_compound Nuclear magnetic resonance Materials Chemistry Radius of gyration symbols Debye |
| Zdroj: | Macromolecules. 32:8611-8620 |
| ISSN: | 1520-5835 0024-9297 |
| DOI: | 10.1021/ma990591h |
| Popis: | A rotational isomeric state model has been developed for the polysaccharide pullulan dissolved in water. The model is consistent with the mean-square radius of gyration and Debye scattering function as measured for pullulan oligomers containing 3, 6, 9, and 12 glucose residues by small-angle X-ray scattering. It is also consistent with the unperturbed chain dimensions of high molecular weight aqueous pullulan and the temperature coefficient of the unperturbed dimensions. The model is based on identification of an initial set of rotational isomeric states using the AMBER* molecular mechanics force field in conjunction with a continuum model for aqueous solvation. The relative weights of the rotational isomeric states were subsequently adjusted to achieve an optimized fit to the data. Three important rotational isomeric states (encompassing together more than 77% of the probability distribution) are identified for the (1→6)-linkage while a single state is recognized for the (1→4)-linkage. One of the states ... |
| Databáze: | OpenAIRE |
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