title: 2-Acetyl-1,3-cyclopentanedione-oxovanadium(IV) complexes. Acidity and implications for gastrointestinal absorption.
abstract: Since vanadyl sulphate has demonstrated insulin-like effects on glucose metabolism in animal and human trials, and organic vanadium complexes are better absorbed by the intestinal tract than vanadyl species, in this work the complexation of oxovanadium(IV) with 2-acetyl-1,3-cyclopentanedione is studied. Kinetic and equilibria in aqueous 1:1 chelation are investigated spectrophotometrically in aqueous solution at 25 degrees C. The mechanism proposed to account for the kinetic data involves a reversible pathway where VO(+2) reacts with the enolate ion of the ligand. From calculated kinetic and thermodynamic parameters, it can be expected that the rates between final and initial monocharged complex concentration could help a better control of the absorption through the lipophilic membranes in the intestinal tract.
authors.affiliation: Dpto. Ingeniería Agrícola y Forestal (Area de Tecnología de los Alimentos), E.T.S. Ingeníaras Agrarias, Universidad de Valladolid, 34004 Palencia, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Rojas
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Blanco
authors.forename: Felicidad
authors.initials: F
authors.lastname: Ronda
authors.forename: Manuel
authors.initials: M
authors.lastname: Gomez
authors.forename: Pedro A
authors.initials: PA
authors.lastname: Caballero
mesh_terms: D000818:Animals; D002614:Chelating Agents; D003517:Cyclopentanes / Q000737:chemistry* / Q000493:pharmacokinetics; D004578:Electron Spin Resonance Spectroscopy; D006863:Hydrogen-Ion Concentration; D007408:Intestinal Absorption / Q000187:drug effects*; D007700:Kinetics; D013329:Structure-Activity Relationship; D014638:Vanadates / Q000737:chemistry / Q000493:pharmacokinetics*; D017968:Vanadium Compounds / Q000737:chemistry / Q000493:pharmacokinetics
chemical_list: D002614:Chelating Agents; D003517:Cyclopentanes; D017968:Vanadium Compounds; C075743:oxovanadium IV; D014638:Vanadates; C034028:vanadyl sulfate