Purpurogallin: A Multi-targeting Benzotropolone with Promising Anti-cancer and Chronic Disease Applications

Purpurogallin is a naturally occurring benzotropolone derivative, first isolated from oak nutgalls, and has emerged as a molecule of significant biomedical interest due to its broad spectrum of bioactivities. It exhibits anticancer, antioxidant, anti-inflammatory, anti-platelet, anti-thrombotic, antibacterial, antimalarial, diabetic nephropathy, and neuroprotective properties. Mechanistically, purpurogallin modulates several key signaling pathways, including NF-κB, MAPK, c-Fos, NFATc1, and TNNT2, which are central to inflammation, apoptosis, and cellular proliferation. Its anticancer potential is underscored by its ability to inhibit crucial oncogenic targets such as Pololike kinases (PLKs), xanthine oxidase, and catechol-O-methyltransferase (COMT). These interactions disrupt cancer cell growth, induce apoptosis, and maintain cellular redox homeostasis. Additionally, its structural resemblance to tropolone-based pharmacophores enhances its utility as a scaffold in anticancer drug development, allowing for strategic chemical modifications to improve efficacy and selectivity. Recent research highlights its promise in the treatment of oxidative stressrelated disorders, including diabetic nephropathy and neurodegenerative diseases, through its potent redox-modulating capabilities. This multifaceted bioactivity profile positions purpurogallin as a compelling candidate for therapeutic advancement. This review delves into the current body of evidence on purpurogallin's biological effects, molecular mechanisms, and synthesis, emphasizing its dual functionality in targeting cancer-related signaling and oxidative stress. Such findings support further investigation into its pharmacological optimization and development as a lead compound in future drug discovery efforts.