Azide as a photolabile ligand in gold(I) therapeutics

• Novel gold(I) azido complexes have been synthesised. • Their potential as chemotherapeutic agents against lung cancer has been evaluated. • Two complexes exhibited modulation of their biological activity upon light irradiation. • Transition metal azido complexes show promise as photoactivated prodrugs. Gold-based compounds are gaining attention as potential alternatives to platinum-based chemotherapeutics due to their high antiproliferative activity and unique mechanisms of action. However, challenges remain in enhancing their selectivity and reducing side effects. In this study, we synthesized and characterized a series of gold(I) azido complexes featuring phosphine and N-heterocyclic carbene ligands. Their cytotoxicity was assessed against human lung carcinoma (A549) and non-cancerous fibroblast (MRC-5) cells, revealing micromolar-range antiproliferative effects with varying selectivity. Additionally, their use as photoactivated chemotherapy (PACT) agents was explored, with some complexes displaying modulation of their cytotoxicity upon light exposure. These findings suggest that gold azido complexes could serve as promising drug candidates for chemotherapy treatments. Gold(I) azido complexes with phosphine or N-heterocyclic carbene ligands were evaluated as potential chemotherapeutics against lung cancer. The complexes exhibit micromolar range toxicity, some demonstrating moderate selectivity. Notably, two complexes showed a two-fold increase in cytotoxicity upon 450 nm irradiation compared to their activity in the dark, demonstrating their potential as photoactivated chemotherapy agents.