title: Relative acidity scale of bile acids through ESI-MS measurements.
abstract: The anion proton affinity of the most important human bile acids and those of the corresponding keto bile acids have been examined in order to establish a true (intrinsic) relative acidity scale. The measurements have been carried out in the gas-phase using the Cooks' kinetic method. The remarkably high acidity of cholic acid with respect to the other bile acids was confirmed. Rationalization of the differences found for the various acids and comparisons with the available solution-phase data are discussed with the help of theoretical calculations.
authors.affiliation: Dipartimento di Chimica, Università della Calabria, Via Bucci 12 C, 87036 Rende (CS), Italy. o.bortolini@unical.it
authors.forename: Olga
authors.initials: O
authors.lastname: Bortolini
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Fantin
authors.forename: Valeria
authors.initials: V
authors.lastname: Ferretti
authors.forename: Marco
authors.initials: M
authors.lastname: Fogagnolo
authors.forename: Pier Paolo
authors.initials: PP
authors.lastname: Giovannini
authors.forename: Alessandro
authors.initials: A
authors.lastname: Medici
mesh_terms: D001647:Bile Acids and Salts / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D008968:Molecular Conformation; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry
chemical_list: D001647:Bile Acids and Salts