SALMO and S₃M: A Saliva Model and a Single Saliva Salt Model for Equilibrium Studies

Abstract

A model of synthetic saliva (SALMO, SALiva MOdel) is proposed for its use as standard medium in in vitro equilibrium and speciation studies of real saliva. The concentrations come out from the literature analysis of the composition of both real saliva and synthetic saliva. The chief interactions of main inorganic components of saliva, as well as urea and amino acids, are taken into account on the basis of a complex formation model, which also considers the dependence of the stability constants of these species on ionic strength and temperature. These last features allow the modelling of the speciation of saliva in different physiological conditions deriving from processes like dilution, pH, and temperature changes. To simplify equilibrium calculations, a plain approach is also proposed, in order to take into account all the interactions among the major components of saliva, by considering the inorganic components of saliva as a single 1 : 1 salt (MX), whose concentration is c MX = (1/2)∑c i (c i = analytical concentration of all the ions) and z ion charge calculated as z=±(I/c MX)1/2 = ±1.163. The use of the Single Saliva Salt Model (S3M) considerably reduces the complexity of the systems to be investigated. In fact, only four species deriving from internal ionic medium interactions must be considered.

Interaction of N-acetyl-l-cysteine with Na+, Ca2+, Mg2+ and Zn2+. Thermodynamic aspects, chemical speciation and sequestering ability in natural fluids

“…In one attempt, the ZnL(OH) 2 2− has been determined as an alternative to the ZnL 2 (OH) 3− , but the statistical parameters of the fits worsened significantly and the model containing the ZnL 2 (OH) 3− instead of the ZnL(OH) 2 2− was chosen. For the selection of the best speciation scheme, some usual procedures were adopted [ 72 , 73 ].…”

“…(9) . For example, the value of the “apparent” complex formation constant of the ZnL 0 (aq) species should be corrected by the formation of the NaL − (values in Table 3 ) and the ZnCl + [ 73 ] species. If more than one ligand is present in the species this must be considered, as well as in case of protonated species.…”

Release of Major Peanut Allergens from Their Matrix under Various pH and Simulated Saliva Conditions—Ara h2 and Ara h6 Are Readily Bio-Accessible

“…In resting conditions, saliva pH ranges normally from 6.5 to 7.5, while the pH may rise to above 8 under chewing conditions [ 33 ]. On the basis of the literature and experimental data, Crea et al [ 18 ] proposed a composition for artificial saliva. To investigate peanut protein dissolution under saliva conditions, we used the essential elements of this composition and set the pH at 7.8 to mimic the chewing conditions.…”

“…A saliva-like buffer was made essentially according to Crea et al [ 18 ], containing 8.85 mM NaCl, 7.75 KCl, 11.45 mM NaHCO 3 , 4.18 mM NaH 2 PO 4 , 2.83 mM Na 2 CO 3 , pH = 7.8. The buffers for the pH range 6.5–8.5 were in 50 mM phosphate, using different ratios of monosodium phosphate and disodium phosphate to achieve the target pH, essentially following an online buffer calculator [ 19 ].…”

On the interaction of phytate with proton and monocharged inorganic cations in different ionic media, and modeling of acid-base properties at low ionic strength

“…Further details on both the theory and some applications of this approach can be found in references [20,44,45,[55][56][57]. Here it is sufficient to remember that the stability constants of weak complexes between a given ligand and the cation of a supporting electrolyte may be calculated by the so-called DpK method, from the comparison of protonation data in this medium and those obtained in a non-interacting one (tetraalkylammonium salts for O-donor ligands) using suitable computer programs [58].…”