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. T ...

'' (and is named after the genus ''

Xerocomus ''Xerocomus'' is a genus of poroid fungi related to ''Boletus''. Many mycologists did not originally recognize the distinction between the two genera and placed ''Xerocomus'' taxa in genus ''Boletus''. However, several molecular phylogenetic stu ...

''). 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-organge 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 one of the fungi that cause damage to timber referred to as dry rot. It is a basidiomycete in the order Boletales. The ''Serpula lacrymans'' has the ability to rapidly colonise sites through unique and highly specialise ...

''. It is soluble in

methanol Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical and the simplest aliphatic alcohol, with the formula C H3 O H (a methyl group linked to a hydroxyl group, often abbreviated as MeOH). It is a ...

. 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 Norbadione A is a pigment found in the bay bolete mushroom (''Boletus badius''). A polyphenol, norbadione A is related to a family of mushroom pigments known as pulvinic acids. The molecule has also been reported as a potassium salt from the ...

, which are found in the mushroom ''

Scleroderma citrinum ''Scleroderma citrinum'', commonly known as the common earthball, pigskin poison puffball, or common earth ball, is the most common species of earthball in the UK and occurs widely in woods, heathland and in short grass from autumn to winter. ''S ...

'' 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. It i ...

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. Polyphenols Catechols Furanones Carboxylic acids