Synthesis, characterization, and in vitro anticancer activity of a series of N (4) dimethyl isatin thiosemicarbazones and their copper(II) complexes

A series of N(4) dimethyl isatin thiosemicarbazones (1-4) and their copper(II) complexes (5-8) have been synthesized and characterized by elemental analysis and spectroscopic techniques (FTIR NMR, ESI-HRMS, UV-Vis,EPR). TGA, EPR, and PXRD studies suggested thermal stability and distorted square planar geometry of mononuclear copper(II) complexes with monoclinic crystal systems of P 1211 and P 21 symmetry. Single crystal X-ray study of Istdma revealed its structure in thione tautomeric form. The in vitro cytotoxic study against breast cancer; MCF-7, skin cancer; A431, and human normal prostate epithelium cell, PNT2 showed that all the compounds exhibited significant cell growth inhibition by 22-71 % (Istdma; 22 % (A431), [Cu(Fistdma)Cl]; 71 % (MCF-7)). [Cu(Fistdma)Cl] also showed high cell growth inhibition (53 %) toward the A431 cell line. Except [Cu (Bristdma)Cl], all the complexes ([Cu(Istdma)Cl], [Cu(Fistdma)Cl], and [Cu(Clistdma)Cl]) have been found to exhibit higher anticancer activity than their respective ligands. The colony formation assay of [Cu(Fistdma)Cl]; [Cu(Clistdma)Cl] and PI staining of [Cu(Fistdma)Cl] suggested the cell growth inhibition of cancer cells in a dose-dependent manner via an apoptotic pathway.