Phlorotannin
Encyclopedia
A phlorotannin is a type of tannin
found in brown algae
such as kelp
s and rockweeds or sargassacean
species. Contrary to hydrolysable or condensed tannins, these compounds are oligomer
s of phloroglucinol
(polyphloroglucinols). Phlorotannins are further classified as fucols, phlorethols or fuhalols.
Examples of such compounds are fucodiphlorethol G from the seaweed Ecklonia cava
, eckol
from Ecklonia
species or phlorofucofuroeckol-B from Eisenia arborea
.
The reason why brown algae produce phlorotannins is still unclear. They may have a role in plant defense or resource dynamics or in metal sequestration or a protection against light (UV radiations) or act as an algicide against dinoflagellates.
Tannin
A tannin is an astringent, bitter plant polyphenolic compound that binds to and precipitates proteins and various other organic compounds including amino acids and alkaloids.The term tannin refers to the use of...
found in brown algae
Brown algae
The Phaeophyceae or brown algae , is a large group of mostly marine multicellular algae, including many seaweeds of colder Northern Hemisphere waters. They play an important role in marine environments, both as food and for the habitats they form...
such as kelp
Kelp
Kelps are large seaweeds belonging to the brown algae in the order Laminariales. There are about 30 different genera....
s and rockweeds or sargassacean
Sargassaceae
Sargassaceae is a family of brown algae.-External links:...
species. Contrary to hydrolysable or condensed tannins, these compounds are oligomer
Oligomer
In chemistry, an oligomer is a molecule that consists of a few monomer units , in contrast to a polymer that, at least in principle, consists of an unlimited number of monomers. Dimers, trimers, and tetramers are oligomers. Many oils are oligomeric, such as liquid paraffin...
s of phloroglucinol
Phloroglucinol
Phloroglucinol is a benzenetriol. It is an organic compound that is used in the synthesis of pharmaceuticals and explosives. This molecule exists in two forms, or tautomers, 1,3,5-trihydroxybenzene, which has phenol-like, and 1,3,5-cyclohexanetrione , which has ketone-like character. These two...
(polyphloroglucinols). Phlorotannins are further classified as fucols, phlorethols or fuhalols.
Examples of such compounds are fucodiphlorethol G from the seaweed Ecklonia cava
Ecklonia cava
Ecklonia cava is a species of brown alga found in the ocean off Japan and Korea.It is used as an herbal remedy in the form of an extract called Seanol, a polyphenol. Another phlorotannin-rich natural agent, Ventol, is also extract from E. cava. One of the phlorotannins component is called...
, eckol
Eckol
Eckol is a phlorotannin isolated from brown algae Ecklonia species. The molecule possesses a dibenzo-p-dioxin skeleton and a phloroglucinol component. The molecule can also be viewed as a phloroglucinol trimer. It exhibits an anti-plasmin inhibitory effect and a radioprotective effect in mice....
from Ecklonia
Ecklonia
Ecklonia is a genus of kelp belonging to the family Lessoniaceae.There are nine species:* Ecklonia biruncinata* Ecklonia brevipes* Ecklonia cava* Ecklonia fastigiata* Ecklonia kurome* Ecklonia maxima* Ecklonia muratii...
species or phlorofucofuroeckol-B from Eisenia arborea
Eisenia arborea
Eisenia arborea, or the southern sea palm , is a species of kelp.Phlorofucofuroeckol-B, a phlorotannin can be isolated from E. arborea....
.
The reason why brown algae produce phlorotannins is still unclear. They may have a role in plant defense or resource dynamics or in metal sequestration or a protection against light (UV radiations) or act as an algicide against dinoflagellates.