Azaphilones: a class of fungal metabolites with diverse biological activities

This review presents an overview of azaphilones isolated from different species of fungi, detailing their chemical structures and biological activities as covered in the recent literature. Over 170 different azaphilone compounds occur in fungi belonging to 23 genera from 13 families: these azaphilones can be classified into ten different structural groups. Numerous azaphilone structures have been described, particularly from members of the Trichocomaceae and Xylariaceae families. Azaphilones exhibit a wide range of interesting biological activities, such as antimicrobial, antifungal, antiviral, antioxidant, cytotoxic, nematicidal and anti-inflammatory activities. Many of these effects may be explained by the reactions of azaphilones with amino groups, such as those found in amino acids, proteins and nucleic acids, resulting in the formation of vinylogous gamma-pyridones.