C. Blaquiere, G. Berthon
Mar 1, 1987
Citations
1
Influential Citations
24
Citations
Quality indicators
Journal
Inorganica Chimica Acta
Abstract
Abstract Associations of Mg2+ ions with organic ligands are frequently advertised as likely to enhance the bioavailability of magnesium from orally administered commercial preparations. However, no systematic study of the relevant equilibria has been produced so far to substantiate these assertions, and no superiority has yet been demonstrated for any magnesium salt on clinical grounds. After a review concerning different aspects of magnesium gastrointestinal absorption, in particular with respect to calcium interactions, this paper deals with the determination of formation constants for magnesium complexes with glutamate, aspartate, glycinate, lactate, pyroglutamate, pyridoxine and citrate, under physiological conditions of ionic strength (0.15 mol dm−3) and temperature (37 °C). Corresponding results are then used to assess the potential capacity of each of these ligands to mobilise Mg2+ ions into membrane diffusible complexes. At usual therapeutic concentrations, pyroglutamate and pyridoxine do not coordinate magnesium in appreciable amounts, and glycinate and lactate do not form any neutral complex. In contrast, glutamate, aspartate and citrate do form neutral magnesium species; the extent of their expected effects with respect to magnesium uptake by enterocyte membranes is discussed on the basis of relevant computer simulations. Potential calcium interactions are also examined, which required the determination of formation constants for calcium complexes with these three ligands.