Mixed Ternary Complexes of Sparfloxacin with Some Biologically Important Amino Acids

Potentiometric measurements for the interaction of sparfloxacin (SPFX) and the metal ions Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) with the amino acids (AA) aspartic acid, alanine, valine, glutamic acid, threonine, methionine, arginine, phenylalanine were studied. The formation constants for the 1:1 binary and 1:1:1 ternary complexes in 10% (v/v) ethanol–water, I = 0.1 mol⋅L−1 KNO3 and 25 °C were measured. The values were refined using the HYPERQUAD computer program. The binding constants of M(II)–SPFX binary complexes with bovine serum albumin using absorption titration experiments were also determined.