Emodin (6-methyl-1,3,8-trihydroxyanthraquinone) is a chemical compound, of the anthraquinone family, that can be isolated from

rhubarb Rhubarb is the fleshy, edible stalks ( petioles) of species and hybrids (culinary rhubarb) of '' Rheum'' in the family Polygonaceae, which are cooked and used for food. The whole plant – a herbaceous perennial growing from short, thick rhi ...

buckthorn ''Rhamnus'' is a genus of about 110 accepted species of shrubs or small trees, commonly known as buckthorns, in the family Rhamnaceae. Its species range from tall (rarely to ) and are native mainly in east Asia and North America, but found thr ...

, and Japanese knotweed ('' Reynoutria japonica'' syn. ''Polygonum cuspidatum''). Emodin is particularly abundant in the roots of the Chinese rhubarb (Rheum palmatum), knotweed and knotgrass (

Polygonum ''Polygonum'' is a genus of about 130 species of flowering plant in the buckwheat and knotweed family Polygonaceae. Common names include knotweed and knotgrass (though the common names may refer more broadly to plants from Polygonaceae). In ...

cuspidatum and multiflorum) as well as Hawaii ‘au‘auko‘i cassia seeds or coffee weed (Semen cassia). It is specifically isolated from Rheum palmatum L. It is also produced by many species of fungi, including members of the genera ''

Aspergillus ' () is a genus consisting of several hundred mold species found in various climates worldwide. ''Aspergillus'' was first catalogued in 1729 by the Italian priest and biologist Pier Antonio Micheli. Viewing the fungi under a microscope, Mic ...

'', ''

Pyrenochaeta Pyrenochaeta is a genus of fungus. It includes the species '' Pyrenochaeta romeroi''. Can cause a disease called eumycetoma Eumycetoma, also known as Madura foot, is a persistent fungal infection of the skin and the tissues just under the ...

'', and '' Pestalotiopsis'', inter alia. The common name is derived from ''Rheum emodi'', a taxonomic synonym of '' Rheum australe'', (Himalayan rhubarb) and synonyms include emodol, frangula emodin, rheum emodin, 3-methyl-1,6,8-trihydroxyanthraquinone, Schüttgelb (Schuttgelb), and Persian Berry Lake.

Pharmacology

Emodin is an active component of several plants used in

Traditional Chinese Medicine Traditional Chinese medicine (TCM) is an alternative medical practice drawn from traditional medicine in China. It has been described as "fraught with pseudoscience", with the majority of its treatments having no logical mechanism of acti ...

(TCM) such as '' Rheum palmatum'', '' Polygonum cuspidatum'' and '' Polygonum multiflorum''. It has various actions including laxative,

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

and antiinflammatory effects, and has also been identified as having potential

antiviral Antiviral drugs are a class of medication used for treating viral infections. Most antivirals target specific viruses, while a broad-spectrum antiviral is effective against a wide range of viruses. Unlike most antibiotics, antiviral drugs do n ...

activity against

coronavirus Coronaviruses are a group of related RNA viruses that cause diseases in mammals and birds. In humans and birds, they cause respiratory tract infections that can range from mild to lethal. Mild illnesses in humans include some cases of the co ...

es such as

SARS-CoV-2 Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is a strain of coronavirus that causes COVID-19 (coronavirus disease 2019), the respiratory illness responsible for the ongoing COVID-19 pandemic. The virus previously had a ...

, being one of the major active components of the antiviral TCM formulation Lianhua Qingwen. A computational study was conducted to investigate the inhibition mechanism on the formation of the Spike-ACE2 protein complex. Specifically, it is seen dose-dependent inhibition in the prevention of infection by the

SARS-Cov-1 Severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1; or Severe acute respiratory syndrome coronavirus, SARS-CoV) is a strain of coronavirus that causes severe acute respiratory syndrome (SARS), the respiratory illness responsible for t ...

whose evidence has stimulated further investigations on

SARS-Cov-2 Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is a strain of coronavirus that causes COVID-19 (coronavirus disease 2019), the respiratory illness responsible for the ongoing COVID-19 pandemic. The virus previously had a ...

. Emodin has been shown to inhibit the ion channel of protein 3a which could play a crucial role in the release of the virus from infected cells.

List of plant species

The following plant species produce emodin: * '' Acalypha australis'' * '' Cassia occidentalis'' * '' Cassia siamea'' *'' Frangula alnus'' * '' Glossostemon bruguieri'' * '' Kalimeris indica'' * ''Polygonum hypoleucum'' * '' Reynoutria japonica'' ( syn. ''Fallopia japonica'') (syn. ''Polygonum cuspidatum'') * '' Rhamnus alnifolia'', the alderleaf buckthorn * '' Rhamnus cathartica'', the common buckthorn * '' Rheum palmatum'' * ''Rumex nepalensis'' * '' Senna obtusifolia'' (syn. ''Cassia obtusifolia'') * '' Thielavia subthermophila'' * ''Ventilago madraspatana''

Compendial status

* British Pharmacopoeia *

List of compounds with carbon number 15 This is a partial list of molecules that contain 15 carbon atoms. See also * Carbon number * List of compounds with carbon number 14 * List of compounds with carbon number 16 This is a partial list of molecules that contain 16 carbon ...

References

{{Purinergics Trihydroxyanthraquinones Virucides Resorcinols 3-Hydroxypropenals within hydroxyquinones