A depside is a type of

polyphenol Polyphenols () are a large family of naturally occurring phenols. They are abundant in plants and structurally diverse. Polyphenols include phenolic acids, flavonoids, tannic acid, and ellagitannin, some of which have been used historically as ...

ic compound composed of two or more monocyclic

aromatic In organic chemistry, aromaticity is a chemical property describing the way in which a conjugated system, conjugated ring of unsaturated bonds, lone pairs, or empty orbitals exhibits a stabilization stronger than would be expected from conjugati ...

units linked by an

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 ...

group. Depsides are most often found 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, but have also been isolated from

higher plants Vascular plants (), also called tracheophytes (, ) or collectively tracheophyta (; ), are plants that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified tissue ( ...

, including species of the

Ericaceae The Ericaceae () are a Family (biology), family of flowering plants, commonly known as the heath or heather family, found most commonly in acidic and infertile growing conditions. The family is large, with about 4,250 known species spread acros ...

Lamiaceae The Lamiaceae ( ) or Labiatae are a family (biology), family of flowering plants commonly known as the mint, deadnettle, or sage family. Many of the plants are aromatic in all parts and include widely used culinary herbs like basil (herb), ba ...

Papaveraceae The Papaveraceae, informally known as the poppy family, are an economically important family (biology), family of about 42 genera and approximately 775 known species of flowering plants in the order Ranunculales. The family is cosmopolitan dis ...

and

Myrtaceae Myrtaceae (), the myrtle family, is a family of dicotyledonous plants placed within the order Myrtales. Myrtle, pōhutukawa, bay rum tree, clove, guava, acca (feijoa), allspice, and eucalyptus are some notable members of this group. All ...

. Certain depsides have

antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy ...

, anti-

HIV The human immunodeficiency viruses (HIV) are two species of '' Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the im ...

antioxidant Antioxidants are Chemical compound, compounds that inhibit Redox, oxidation, a chemical reaction that can produce Radical (chemistry), free radicals. Autoxidation leads to degradation of organic compounds, including living matter. Antioxidants ...

, and anti-proliferative activity ''

in vitro ''In vitro'' (meaning ''in glass'', or ''in the glass'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in ...

''. As inhibitors of

prostaglandin Prostaglandins (PG) are a group of physiology, physiologically active lipid compounds called eicosanoids that have diverse hormone-like effects in animals. Prostaglandins have been found in almost every Tissue (biology), tissue in humans and ot ...

synthesis and leukotriene B₄ biosynthesis, some depsides have ''in vitro'' anti-inflammatory activity. A depsidase is a type of enzyme that cuts depside bonds. One such enzyme is

tannase The enzyme tannase (EC 3.1.1.20) catalyzes the following reaction: : digallate + H2O = 2 gallate It is a key enzyme in the degradation of gallotannins and ellagicitannins, two types of hydrolysable tannins. Specifically, tannase catalyzes the ...

Examples

Gyrophoric acid Gyrophoric acid is a tridepside. It is a double ester of the orsellinic acid. It can also be found in most of the species of the lichen genera '' Actinogyra'', '' Lasallia'', and '' Umbilicaria'' . Natural occurrence and biosynthesis Gyropho ...

, found in the lichen ''

Cryptothecia rubrocincta ''Cryptothecia rubrocincta'' is a species of lichen in the fungal family Arthoniaceae. The species is distributed in subtropical and tropical locations throughout the southeastern United States, as well as Central and South America, and has been ...

'', is a depside.

Merochlorophaeic acid Merochlorophaeic acid is a depside A depside is a type of polyphenolic compound composed of two or more monocyclic aromatic units linked by an ester group. Depsides are most often found in lichens, but have also been isolated from higher plants ...

, isolated from lichens of the genus ''

Cladonia ''Cladonia'' is a genus of moss-like lichenized fungi in the family Cladoniaceae. They are the primary food source for reindeer/caribou. ''Cladonia'' species are of economic importance to reindeer-herders, such as the Sami in Scandinavia or th ...

'', is an inhibitor of

synthesis. Some depsides are described as anti-HIV.

References

{{reflist, 2 Polyphenols Carboxylate esters *

Examples

See also

References