Piloty’s Acid

Piloty’s Acid (CAS No.: 599-71-3) is a classical nitroxyl (HNO) donor and biochemical assay reagent widely employed in redox biology and enzyme modulation studies. Functionally, it undergoes base-catalyzed decomposition to release HNO, with a strongly pH-dependent kinetics profile that enables controlled generation of reactive nitrogen species, making it particularly suitable for investigations under mildly to strongly basic conditions. Piloty’s Acid has been shown to modulate multiple enzymatic systems, including inhibition of yeast aldehyde dehydrogenase and human carbonic anhydrase isoforms I, II, and IV, with activities spanning the nanomolar to micromolar range, as well as effects on yeast alcohol dehydrogenase, indicating its utility as a broad-spectrum probe for enzyme activity regulation. In addition to enzyme inhibition, it exhibits vasorelaxant activity in isolated vascular tissue models, supporting its relevance in studies of cardiovascular signaling and HNO-mediated biological responses. Mechanistically, its effects are associated with HNO release and subsequent modulation of thiol-dependent pathways and metalloenzyme function. Piloty’s Acid is commonly applied in biochemical assays, cell-based systems, and ex vivo tissue models to investigate redox signaling, enzyme inhibition, and nitroxyl pharmacology, with experimental concentrations tailored to specific assay conditions and research objectives.