Research Article Open Access

Chelation Study of Captopril with Cd2+ and Pb2+ Ions

Mohammad Joshaghani1, M.B. Gholivand1 and A.R. Mosavat1
  • 1 Razi University, Iran


The protonation constants of Captopril, (1-(3-mercapto-2-(S)-methyl-1-oxopropyl)-S(L) proline, (CPL) and stabilities of its two divalent metal ions Cd(II) and Pb(II) were determined potentiometrically in two different metal to ligand ratio 1:1 and 1:2 systems and in water and methanol-water binary mixtures using the computer Best program. Two protonation constants were obtained which were assigned to the carboxylic and thiol groups. All protonation and stability constants increased with decreasing the dielectric constant on going from the pure water to the binary mixtures. An excellent similarity in stabilities of studied metal ions strongly suggests that both metal ions are coordinated by CPL in a same manner through the thiol group.

American Journal of Biochemistry and Biotechnology
Volume 4 No. 3, 2008, 245-249


Submitted On: 8 May 2007 Published On: 30 September 2008

How to Cite: Joshaghani, M., Gholivand, M. & Mosavat, A. (2008). Chelation Study of Captopril with Cd2+ and Pb2+ Ions. American Journal of Biochemistry and Biotechnology, 4(3), 245-249.

  • 4 Citations



  • Potentiometry
  • stability constant
  • captopril
  • binary solvents mixture