NIST logo

Publication Citation: Thermodynamics of the hydrolysis reactions of 1-naphthyl acetate, 4-nitrophenyl acetate, and 4-nitrophenyl -L-arabinofuranoside

NIST Authors in Bold

Author(s): Stephen R. Decker; Robert N. Goldberg; Brian E. Lang; William Michener;
Title: Thermodynamics of the hydrolysis reactions of 1-naphthyl acetate, 4-nitrophenyl acetate, and 4-nitrophenyl -L-arabinofuranoside
Published: April 02, 2010
Abstract: Microcalorimetry, high-performance liquid chromatography (HPLC), and liquid chromatography-mass spectrometry (LC-MS) have been used to conduct a thermodynamic investigation of the hydrolysis reactions: {1-naphthyl acetate(aq) + H2O(l) = 1 naphthol(aq) + acetate(aq)}, {4-nitrophenyl acetate(aq) + H2O(l) = 4 nitrophenol(aq) + acetate(aq)}, and {4-nitrophenyl -L-arabinofuranoside(aq) + H2O(l) = L arabinose(aq) + 4-nitrophenol(aq)}. Calorimetrically determined enthalpies of reaction rH(cal) were measured for all three reactions. However, since the positions of equilibrium for all of these reactions were found to lie very far to the right, it was only possible to set lower limits for the values of the apparent equilibrium constants K. A chemical equilibrium model, together with pKs and standard enthalpies of reaction ΔrH for the H+ binding reactions of the reactants and products, was then used to calculate the values of ΔrH for chemical reference reactions that correspond to the overall biochemical reactions that were studied experimentally. The values of Benson estimates of ΔrH for the chemical reference reactions that correspond to the first of the above two reactions were, in all cases, within 16 kJ∙mol-1 of the results obtained in this study. Thermochemical network calculations led to ΔfH = -286.4 kJ∙mol-1 for 1 napthyl acetate(aq) and ΔfH = 364.9 kJ∙mol-1 for 4 nitrophenyl acetate(aq).
Citation: Journal of Physical Chemistry B
Volume: 114
Pages: pp. 16060 - 16067
Keywords: Acetylxylan esterase; 2-Acetyl ¿-xylopyranose; ¿-N-Aabinofuranosidase; 1-Naphthyl acetate; 4 nitrophenyl acetate; 4-Nitrophenyl ¿-L-Arabinofuranoside; Calorimetry; Standard Gibbs free energy and enthalpy
Research Areas: Chemical Engineering & Processing, Chemistry, Chemical Analysis, Thermodynamics
PDF version: PDF Document Click here to retrieve PDF version of paper (279KB)