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

Published

April 2, 2010

Author(s)

Stephen R. Decker, Robert N. Goldberg, Brian Lang, William Michener

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

Pub Type

Journals

Download Paper

Local Download

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

Citation

Decker, S. , Goldberg, R. , Lang, B. and Michener, W. (2010), Thermodynamics of the hydrolysis reactions of 1-naphthyl acetate, 4-nitrophenyl acetate, and 4-nitrophenyl -L-arabinofuranoside, Journal of Physical Chemistry B, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=904030 (Accessed March 13, 2025)