Fragilin is a chemical compound of the

anthraquinone Anthraquinone, also called anthracenedione or dioxoanthracene, is an aromatic hydrocarbon, aromatic organic compound with formula . Several isomers exist but these terms usually refer to 9,10-anthraquinone (IUPAC: 9,10-dioxoanthracene) wherein th ...

class. It has the molecular formula and is a chlorinated derivative of

parietin Parietin is the predominant cortical pigment of lichens in the genus '' Caloplaca'', a secondary product of the lichen '' Xanthoria parietina'', and a pigment found in the roots of curled dock (''Rumex crispus''). It has an orange-yellow color ...

. In 1965, it was reported as a constituent of the

lichen A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...

s ''

Sphaerophorus fragilis ''Sphaerophorus'' a genus of lichenized fungi in the order (biology), order Lecanorales. Members of ''Sphaerophorus'' are List of common names of lichen genera, commonly called ball lichens, coral lichens,Field Guide to California Lichens, Steph ...

'' and ''

Sphaerophorus coralloides ''Sphaerophorus'' a genus of lichenized fungi in the order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ide ...

''. It has since been found in a variety of other lichens including '' Nephroma laevigatum'', ''

Caloplaca ''Caloplaca'' is a lichen genus comprising a number of distinct species. Members of the genus are commonly called firedot lichen, jewel lichen.Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, gold lichens, "ora ...

'', ''

Xanthoria parietina ''Xanthoria parietina'' is a common and widespread lichen-forming fungus in the family Teloschistaceae. Commonly known as the yellow wall lichen, common orange lichen, or maritime sunburst lichen, this foliose lichen, leafy lichen is known f ...

'', and others.

References

{{reflist Anthraquinones Lichen products Chlorine-containing natural products Diols Methoxy compounds