Abstract
A pyrazoline based ligand; (5-(4-chlorophenyl)-3-phenyl-4, 5-dihydro-1H-pyrazole-1-carbothioamide) has been synthesized by Claisen–Schmidt condensation of acetophenone with p-chlorobenzaldehyde, followed by sodium hydroxide assisted cyclization of the resulting chalcone with thiosemicarbazide. Metal ion complexes of the synthesized ligand were prepared with Cu(II) and Ni(II) metal ions, separately and respectively. Ligand and the metal complexes were characterized by elemental analysis, FT-IR, UV–Vis, 1HNMR, ESI-MS and 13CNMR spectroscopic techniques. Molar conductance measurements in DMSO suggested non-electrolytic nature of the complexes. Tetragonally distorted octahedral geometry for copper and octahedral geometry for the nickel complexes was proposed on the basis of UV–Vis spectroscopic studies and magnetic moment measurements. The complexes were investigated for their ability to kill human fungal pathogen Candida by determining MICs (Minimum inhibitory concentrations), inhibition in solid media and ability to produce a possible synergism with conventional most clinically practiced antifungals by disc diffusion assay and FICI (fractional inhibitory concentration index).
► First approach towards the evaluation of Pyrazoline based transition metal complexes as anticandidal agents. ► Complex formation leads to increase in anticandidal activity. ► Drug combination with amphotericin B and fluconazole reversed the order of anticandidal activities. ► A pronounced synergism has been observed in both ligand and the complexes with the conventional antifungals. ► It is exciting to note that the fungicidal potential of normally fungistatic FLC was observed in combination therapy.