Xerocomic acid is a red-orange pigment found in fungi of the order ''

Boletales The Boletales are an order of Agaricomycetes containing over 1300 species with a diverse array of fruiting body types. The boletes are the best known members of this group, and until recently, the Boletales were thought to only contain boletes. ...

'' (and is named after the genus ''

Xerocomus ''Xerocomus'' is a genus of poroid fungi related to ''Boletus''. Most members of ''Xerocomus'' are edible mushroom, edible, though of mediocre gastronomical value and inferior to the sought-after Boletus edulis, porcini. Taxonomy Many mycol ...

''). It is the precursor to

variegatic acid Variegatic acid (3,3',4,4'-tetrahydroxypulvinic acid) is an orange pigment found in some mushrooms. It is responsible for the bluing reaction seen in many bolete mushrooms when they are injured. When mushroom tissue containing variegatic acid is e ...

, and is preceded by

atromentic acid Atromentic acid is a red-orange pigment found in fungi within the Boletales group. It is the precursor to variegatic acid and xerocomic acid, and is preceded by atromentin. As an example, it is isolated from ''Serpula lacrymans''. It is soluble i ...

and

atromentin Atromentin is a natural chemical compound found in Agaricomycetes fungi in the orders Agaricales and Thelephorales. It can also be prepared by laboratory synthesis. Chemically, it is a polyphenol and a benzoquinone. Occurrences Atromentin has ...

. As an example, it is isolated from ''

Serpula lacrymans ''Serpula lacrymans'' is a species of fungi known for causing dry rot. It is a basidiomycete in the order Boletales. It has the ability to rapidly colonise sites through unique and highly specialised mycelium which also leads to greater degrada ...

''. It is soluble in

methanol Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical compound and the simplest aliphatic Alcohol (chemistry), alcohol, with the chemical formula (a methyl group linked to a hydroxyl group, often ab ...

. An oxidase acting on xerocomic acid is responsible for the "bluing" reaction seen in mushrooms. Condensation of two units of xerocomic acid form the pigments sclerocitrin, badione A, and also norbadione A, which are found in the mushroom ''

Scleroderma citrinum ''Scleroderma citrinum'', commonly known as the common earthball, pigskin poison puffball, or common earth ball, is a species of earthball fungus found in Europe and in North America. It is the most common species of Scleroderma (genus), earthba ...

'' Pers. Variants include

isoxerocomic acid Isoxerocomic acid is a red-orange pigment found in ''Boletales''. It is the precursor to variegatic acid, and is preceded by atromentic acid and atromentin. As an example, it is isolated from ''Serpula lacrymans''. It is soluble in methanol ...

and ''O''-methylxerocomic acid.

References

{{Reflist, refs= {{cite book, last1=Gill, first1=M., last2=Steglich, first2= W., year=1987, title= Pigments of fungi (Macromycetes). , series= Fortschritte der Chemie organischer Naturstoffe / Progress in the Chemistry of Organic Natural Products, volume= 51, pages= 1–317, doi=10.1007/978-3-7091-6971-1_1, isbn=978-3-7091-7456-2 . Polyphenols Catechols Furanones Acetic acids Fungal pigments