A Review of Curcuminoid Derivatives as Next-Generation Depigmenting Agents: Structure-activity Relationships and their Mechanisms

Hyperpigmentation is a persistent challenge, and current depigmenting agents, such as kojic acid, arbutin, and resveratrol, often exhibit limited efficacy and raise safety concerns. Curcuminoids, a class of natural polyphenolic compounds, have emerged as promising scaffolds due to their potent anti-tyrosinase activity and broad inhibitory effects on melanogenesis. This review summarises advances in curcuminoid derivatives and structurally related analogues, including diarylheptanoids, diarylpentanoids, and chalconoids. Key features of the structure–activity relationship (SAR), such as conjugated ketone linkers and para-hydroxyl substitutions, enhance tyrosinase inhibition and modulate melanogenic signalling pathways. Collectively, these insights emphasise the potential of curcuminoid-based scaffolds as safer and more effective next-generation depigmenting agents.