Punicalagin is an ellagitannin, a type of phenolic compounds. It is found in forms alpha and beta in pomegranates (Punica granatum), in Terminalia catappa and Terminalia myriocarpa, and in Combretum molle, the velvet bushwillow, is a plant species found in South Africa. These three genera are all Myrtales and the last two are both Combretaceae.

Punicalagin is water-soluble and has high bioavailability. They are known to hydrolyze into smaller phenolic compounds such as ellagic acid in vivo where one potential mechanism is hydrolysis across the mitochondrial membrane of cultured human colon cells. It is a highly active carbonic anhydrase inhibitor.