Uncommon temperature effect on the interaction between levodopa and beta-cyclodextrin seen by diffusometry and NMR spectroscopy

作者：Barros M C F; Ribeiro Ana C F^*; Esteso Miguel A^*; Valente A J M; Luisa Ramos M; Burrows Hugh D; Lobo Victor M M; Leaist Derek G

来源：Journal of Chemical Thermodynamics, 2017, 112: 314-320.

DOI：10.1016/j.jct.2017.05.016

• Levodopa
• Diffusion coefficient
• Transport properties
• Aqueous Solutions
• NMR spectroscopy

Experimental ternary mutual diffusion coefficients (D-11, D-22, D-12 and D-21, obtained by the Taylor dispersion method, are reported for aqueous solutions of levodopa (L-dopa) + beta-cyclodextrin (beta-CD) solutions at 310.15 K and concentrations up to 0.007 mol dm(-3). Comparison of these experimental results with data predicted by a model of the diffusion that includes inclusion complexes, it is possible to conclude that the association equilibrium at 310.15 K has little effect on the diffusion properties. Support for this comes from H-1 NMR spectroscopy, which shows that there are no interactions, which may be related to the reduced L-dopa/cavity interactions resulting from both the amine and carboxylate groups on L-dopa being charged.

• 出版日期2017-9