Natural product-conjugated gold(I) complexes: Coordination chemistry and biomedical applications

Natural products are a rich source of pharmacologically active scaffolds for anticancer drug discovery, and their integration with metal centres represents an attractive strategy for the development of novel metallodrugs. Gold(I) complexes are emerging as versatile anticancer agents, distinguished by their unique coordination chemistry and ability to modulate multiple cellular pathways. Incorporation of natural product scaffolds with gold(I) enhances biological activity, as these frameworks provide inherent recognition elements, redox activity, and structural complexity that synergistically complement the reactivity of the gold(I) centre. This review analyses natural product-conjugated gold(I) complexes, organised according to ligand classes, including terpenoids, phenolics, polyketides, and phenylpropanoids, with emphasis on coordination-driven structure-activity relationships. Beyond cytotoxic effects, recent studies discussed herein demonstrate their ability to suppress inflammation and trigger immunogenic cell death, supporting both direct and immune-mediated anticancer responses. Additionally, selected complexes exhibit imaging capabilities, illustrating how natural product scaffolds confer multifunctional therapeutic profiles. Building on these properties, emerging strategies are extending gold(I) chemistry into advanced biomedical applications, including enzyme-responsive delivery with peptide–gold conjugates, biomaterial integration in coumarin hydrogels, nucleic acid interactions using caffeine-derived ligands, drug repurposing through indomethacin-based gold complexes, and targeted radiochemotherapy via biotin-functionalised gold complexes. Collectively, these developments position natural product-gold(I) hybrids as versatile platforms with significant potential for next-generation cancer therapy.