Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/197688
Type: Artigo de periódico
Title: Use Of Water Spin-spin Relaxation Rate To Probe The Solvation Of Cyclodextrins In Aqueous Solutions.
Author: Sabadini, Edvaldo
do Carmo Egídio, Fernanda
Fujiwara, Fred Yukio
Cosgrove, Terence
Abstract: 1H spin-spin relaxation rate constant, R2, of water was measured by using the Carr-Purcell-Meiboom-Gill sequence in aqueous solutions of native cyclodextrins (alpha, beta, and gamma-CD) and chemically modified CDs in order to probe the structuring of the water surrounding these cyclic carbohydrate molecules. R2 values for water in solutions containing glucose and dextran were also measured for comparison. A two-site model for bonded and free water molecules was used to fit the results for the dependence of R2 on the solute concentrations. The order of relaxation rates for water in aqueous solution at a fixed specific hydroxyl group concentration is glucose>dextran congruent with CDs. No significant difference was observed for R2 of water in solutions containing native CDs, which indicates that the size and nature of the cavity has a small effect on the spin-spin relaxation times of water. The lower relaxation rate for water in CD solutions was attributed to the intramolecular hydrogen bonding formed between the secondary hydroxyl groups that line the rim of the CDs. For comparison, the relaxation rates for water in solutions of two chemically modified CDs were also studied.
Subject: Cyclodextrins
Hydrogen Bonding
Magnetic Resonance Spectroscopy
Solubility
Solutions
Spin Labels
Water
Alpha-cyclodextrins
Beta-cyclodextrins
Gamma-cyclodextrins
Rights: fechado
Identifier DOI: 10.1021/jp710013h
Address: http://www.ncbi.nlm.nih.gov/pubmed/18303884
Date Issue: 2008
Appears in Collections:Unicamp - Artigos e Outros Documentos

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