Details

Autor(en) / Beteiligte

• Crea, Francesco
• De Stefano, Concetta
• Irto, Anna
• Lando, Gabriele
• Materazzi, Stefano
• Milea, Demetrio
• Pettignano, Alberto
• Sammartano, Silvio

Titel

Understanding the Solution Behavior of Epinephrine in the Presence of Toxic Cations: A Thermodynamic Investigation in Different Experimental Conditions

Ist Teil von

• Molecules (Basel, Switzerland), 2020-01, Vol.25 (3), p.511

Ort / Verlag

Switzerland: MDPI AG

Erscheinungsjahr

2020

Link zum Volltext

Quelle

EZB*

Beschreibungen/Notizen

• The interactions of epinephrine (( )-(-)-3,4-dihydroxy-α-(methylaminomethyl)benzyl alcohol; ) with different toxic cations (methylmercury(II): CH Hg ; dimethyltin(IV): (CH ) Sn ; dioxouranium(VI): UO ) were studied in NaCl at different ionic strengths and at = 298.15 K ( = 310.15 K for (CH ) Sn ). The enthalpy changes for the protonation of epinephrine and its complex formation with UO were also determined using isoperibolic titration calorimetry: = -39 ± 1 kJ mol , = -67 ± 1 kJ mol (overall reaction), = -26 ± 4 kJ mol , and = 39 ± 2 kJ mol . The results were that UO complexation by was an entropy-driven process. The dependence on the ionic strength of protonation and the complex formation constants was modeled using the extended Debye-Hückel, specific ion interaction theory (SIT), and Pitzer approaches. The sequestering ability of adrenaline toward the investigated cations was evaluated using the calculation of pL parameters. The sequestering ability trend resulted in the following: UO >> (CH ) Sn > CH Hg . For example, at = 0.15 mol dm and pH = 7.4 (pH = 9.5 for CH Hg ), pL = 7.68, 5.64, and 2.40 for UO , (CH ) Sn , and CH Hg , respectively. Here, the pH is with respect to ionic strength in terms of sequestration.