Recent advances in thiosemicarbazone metal complexes: structure–activity relationship and therapeutic prospects

Thiosemicarbazones are a structurally diverse class of Schiff bases formed through the condensation of carbonyl compounds with thiosemicarbazide derivatives. Their synthetic accessibility, tunable coordination behavior, and broad spectrum of applications have positioned them as key ligands in medicinal and bioinorganic chemistry. Metal coordination frequently results in a marked amplification of biological activity, predominantly through chelation effects that alter electronic properties, enhance molecular stability, and improve interactions with biological macromolecules. Concurrently, the alarming rise in antimicrobial resistance has emerged as a critical impediment to effective disease management, leading to chronic infections and reduced responsiveness to conventional drug therapies. Addressing this challenge requires the development of innovative therapeutic agents. Accordingly, this review critically consolidates established and recent research, highlighting significant advances in the biological potential of thiosemicarbazone-derived metal complexes. Schiff base complexes are proved to be simple compounds possessing high activity. Thiosemicarbazone is a Schiff base having semicarbazide group. Thiosemicarbazone Schiff base is known for its profuse biological applications in various fields. Biological activity of thiosemicarbazone was enhanced on complexation.