Synthesis, spectroscopic and thermal characterization of sulpiride complexes of iron, manganese, copper, cobalt, nickel, and zinc salts. Antibacterial and antifungal activity

Abstract

Sulpiride (SPR; L) is a substituted benzamide antipsychotic which is reported to be a selective antagonist of central dopamine receptors and claimed to have mood-elevating properties. The ligation behaviour of SPR drug is studied in order to give an idea about its potentiality towards some transition metals in vitro systems. Metal complexes of SPR have been synthesized by reaction with different metal chlorides. The metal complexes of SPR with the formula [MCl(2)(L)(2)(H(2)O)(2)].nH(2)O [M=Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); n=0-2] and [FeCl(2)(HL)(H(2)O)(3)]Cl.H(2)O have been synthesized and characterized using elemental analysis (CHN), electronic (infrared, solid reflectance and (1)H NMR spectra) and thermal analyses (TG and DTA). The molar conductance data reveal that the bivalent metal chelates are non-electrolytes while Fe(III) complex is 1:1 electrolyte. IR spectra show that SPR is coordinated to the metal ions in a neutral monodentate manner with the amide O. From the magnetic and solid reflectance spectra, octahedral geometry is suggested. The thermal decomposition processes of these complexes were discussed. The correlation coefficient, the activation energies, E*, the pre-exponential factor, A, and the entropies, DeltaS*, enthalpies, DeltaH*, Gibbs free energies, DeltaG*, of the thermal decomposition reactions have been derived from thermogravimetric (TG) and differential thermogravimetric (DTG) curves. The synthesized ligand and its metal complexes were also screened for their antibacterial and antifungal activity against bacterial species (Escherichia coli and Staphylococcus aureus) and fungi (Aspergillus flavus and Candida albicans). The activity data show that the metal complexes are found to have antibacterial and antifungal activity than the parent drug and less than the standard.