Depsidones (+ " depside" + "one") are

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

s that are sometimes found as

secondary metabolite Secondary metabolites, also called ''specialised metabolites'', ''secondary products'', or ''natural products'', are organic compounds produced by any lifeform, e.g. bacteria, archaea, fungi, animals, or plants, which are not directly involved ...

s in

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. They are

ester In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distin ...

s that are both depsides and cyclic ethers. An example is

norstictic acid Norstictic acid is a depsidone produced as a secondary metabolites in lichens. The compound contains both an aldehyde carbonyl group and an adjacent hydroxyl In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical fo ...

References

{{reflist Biochemistry Carboxylate esters