Adamantane-appended koneramine metal complexes: anticancer activity and therapeutic potential

Adamantane-based compounds have gained significant interest in drug discovery due to their versatile therapeutic potential and hydrophobic character, which allows for structural modifications across a wide range of drug classes. Their distinct structural and physicochemical properties continue to make them valuable assets in the design and development of new pharmaceuticals. Herein, we report the synthesis of three new metal complexes derived from an adamantane-appended tridentate koneramine ligand (L^kAd), coordinated with Cu(II), Zn(II), and Fe(III). These complexes exhibit good stability and have been thoroughly characterized using ESI-MS, Nuclear Magnetic Resonance spectroscopy, and single-crystal X-ray diffraction (SCXRD) analysis. The crystal structures of the [Cu(L^kAd)Cl₂], [Zn(L^kAd)Cl₂], and [Fe(L^kAd)Cl₃] complexes revealed that Cu(II) and Zn(II) ions occupy distorted trigonal bipyramidal and distorted square pyramidal geometries, respectively, while Fe (III) adopts a distorted octahedral coordination environment. All the three metal complexes were evaluated for their antiproliferative activities against one human cancer cell line, human triple negative breast cancer cells MDA-MB-231 and non-cancerous human embryonic kidney cells (HEK-293).