Piericidin A (AR-054) is a natural mitochondrial NADH-ubiquinone oxidoreductase (complex I) inhibitor. Piericidin A is a potent neurotoxin and inhibits mitochondrial respiration by disrupting the electron transport system through its action on NADH-ubiquinone reductase. Piericidin A is also a potential quorum-sensing inhibitor that suppresses the expression of the virulence genes of Erwinia carotovora subsp. atroseptica (Eca). Piericidin A is an ADC cytotoxin and has anti-bacterial, anticancer, insecticidal activity.