Purpurin is an anthraquinone found in madder root that is occasionally used as a pigment dye. Purpurin also exhibits anti-angiogenic, antifungal, antibiotic, and antioxidative activities. In vivo and in vitro, purpurin suppresses VEGF-induced cell invasion and tube formation by inhibiting adipocyte-derived leucine aminopeptidase. In other cellular models, purpurin acts as a radical scavenger. This compound inhibits growth of Candida by inducing apoptosis. Additionally, purpurin displays antibacterial activity against gram positive and gram negative bacteria by inhibiting O-acetylpeptidoglycan esterase.