Characterization by Potentiometric Procedures of the Stability Constants of the Binary and Ternary Complexes of Cu(II) and Duloxetine Drug with Amino Acids

Table 1

The protonation constants of the ligands at 25°C and 0.10 mol·L⁻¹ ionic strength.

System
Duloxetine (D)	9.34 (0.01)
Glycine (Gly)	9.61 (0.02)	2.48 (0.02)
Alanine (Ala)	9.80 (0.01)	2.82 (0.03)
Valine (Val)	9.68 (0.00)	2.50 (0.01)
Proline (Pro)	10.65 (0.009)	2.53 (0.01)
β-Phenylalanine (Phe)	9.20 (0.01)	2.61 (0.03)
S-Methylcysteine (Met)	8.65 (0.02)
Threonine (Thr)	9.06 (0.009)	2.01 (0.03)
Ornithine (Orn)	10.58 (0.03)	8.99 (0.04)	1.55 (0.05)
Lysine (Lys)	10.44 (0.01)	9.22 (0.02)
Histidine (Hisd)	9.48 (0.01)	6.28 (0.01)	2.16 (0.04)
Histamine (Hist)	9.88 (0.03)	6.06 (0.05)
Imidazole (Imz)	7.06 (0.01)

Standard deviations are given in parentheses.