Lecanoric acid

Lecanoric acid is a chemical produced by several species of lichen. Lecanoric acid is classified as a polyphenol and a didepside, and it functions as an antioxidant. It is an ester of orsellinic acid with itself.
The acid is named after the lichen Lecanora, in which it was discovered. The acid has also been isolated from Usnea subvacata, Parmotrema stuppuem, Parmotrema tinctorum, ''Parmotrema grayana, Xanthoparmelia arida and Xanthoparmelia lecanorica. A related compound, 5-chlorolecanoric acid, is found in some species of Punctelia''.