Juglone

Juglone (CAS No.: 481-39-0) is a naturally occurring naphthoquinone isolated from walnut species and other members of the Juglandaceae family, widely utilized in biomedical research due to its diverse bioactivities and well-characterized molecular mechanisms. This compound exhibits potent pro-apoptotic effects primarily through activation of the mitochondrial pathway, leading to oxidative stress, disruption of cellular redox balance, and subsequent programmed cell death. Juglone is also recognized as an irreversible inhibitor of peptidyl-prolyl cis/trans isomerases of the parvulin family, including Pin1, thereby modulating protein folding and signaling pathways implicated in cancer and other proliferative disorders. In addition, it suppresses transcription by RNA polymerases I, II, and III at low micromolar concentrations and demonstrates antibacterial, antifungal, and antitumor activities across a range of in vitro systems. Its allelopathic properties, characterized by inhibition of growth, photosynthesis, and respiration in competing organisms, further highlight its broad biological impact. Juglone has been employed extensively in cell-based assays and animal models to investigate apoptosis, oxidative stress responses, fibrosis, and tumor biology, with experimental concentrations typically adjusted according to specific study designs. Collectively, its multifunctional profile makes it a valuable tool compound for mechanistic studies and early-stage drug discovery targeting redox regulation, enzyme inhibition, and cell death pathways.