Thermodynamic considerations in co-ordination. Part XXII. Sequestering ligands for improving the treatment of plumbism and cadmiumism

Zn(II)–D-(−)penicillamine complexes in aqueous solution. Zn-67 nuclear magnetic resonance study

“…This is in good agreement with the fact that only monomeric chemical species are formed in the Zn(I1)-penicillamine system (4,7). The equality between TI and T2 rules out the possibility of an exchange contribution to the transverse relaxation rate.…”

“…The values of the equilibrium constants for the formation of complexes between the penicillamine dianion and transition metal cations show the effectiveness of this molecule to capture Cd(I1) or Hg(II), for example (log 6, = 11.5 and 18.9; log P2 = 19.5 and 25.0 for Cd(I1) and Hg(I1) respectively) (5). In addition to the 1: 1 and 1:2 complexes, diverse protonated complexes or polynuclear species coexist in solution (4,7). Penicillamine has been used in the treatment of metal poisoning (13)(14)(15)(16)(17)(18), can chelate excess copper responsible for the blocking of nerve impulses in Wilson's disease (19,20), is an effective drug in rheumatoid arthritis (2 1-23), idiopathic pulmonary fibrosis (24), and scleroderma (25), and its copper complex possesses some anti-inf ammatory properties (26).…”

“…is a powerful ligand for transition metal cations (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). It acts as a bidentate or tridentate ligand, taking advantage of the coordination ability of its amino, sulfhydryl, and carboxylic groups.…”

Soft- and Hard-Modeling Approaches for the Determination of Stability Constants of Metal–Peptide Systems by Voltammetry

“…As shown in Table 1, the stability constants determined by MCR-ALS (in the above-mentioned manner) are of the same order as those obtained by SQUAD, but quite less precise. Table 2 shows the values of the overall stability constants obtained by correcting the conditional ␤Ј constants for the side reactions of Zn 2ϩ with OH Ϫ ions and those of GSH with H ϩ ions according to log ␤ 11 ϭ log ␤Ј 11 ϩ log ␣ M ϩ log ␣ L [9] log ␤ 22 ϭ log ␤Ј 22 ϩ 2 log ␣ M ϩ 2 log ␣ L [10] log ␤ 12 ϭ log ␤Ј 12 ϩ log ␣ M ϩ 2 log ␣ L , [11] where ␣ M and ␣ L are the side-reaction coefficients of Zn 2ϩ and GSH, computed according to Eq. [2] (by comparison of an acidic KNO 3 blank and a borate blank at pH 8.5) and Eq.…”

Glutathione and N-acetylcysteinylglycine: Protonation and Zn2+ complexation

“…Moreover, it was not evidenced the presence of oligonuclear zinc(II) complexes, although they can be expected due to the number of metal binding sites of GSH as suggested in the literature on the basis of 13 C NMR data. Thus, despite the numbers of paper dealing with the study in solution and in the solid state of Zn 2+ /glutathione complexes [11][12][13][14][15][16][17][18][19], the information on the structural features of GSH complexes are very few as no X-ray structures of metal ions complexes with reduced glutatione have been to date reported.…”