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Phlorotannin
Phlorotannins are a type of tannins found in brown algae such as kelps and rockweeds or sargassacean species, and in a lower amount also in some red algae. Contrary to hydrolysable or condensed tannins, these compounds are oligomers of phloroglucinol (polyphloroglucinols). As they are called tannins, they have the ability to precipitate proteins. It has been noticed that some phlorotannins have the ability to oxidize and form covalent bonds with some proteins. In contrast, under similar experimental conditions three types of terrestrial tannins (procyanidins, profisetinidins, and gallotannins) apparently did not form covalent complexes with proteins. These phenolic compounds are integral structural components of cell walls in brown algae, but they also seem to play many other secondary ecological roles such as protection from UV radiation and defense against grazing. Biosynthesis and localization Most of the phlorotannins' biosynthesis is still unknown, but it appears they ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrafucol A
Tetrafucol A is a fucol-type phlorotannin found in the brown algae ''Ascophyllum nodosum ''Ascophyllum nodosum'' is a large, common cold water seaweed or brown alga ( Phaeophyceae) in the family Fucaceae. Its common names include knotted wrack, egg wrack, feamainn bhuí, rockweed, knotted kelp and Norwegian kelp. It grows only in the ...'', '' Analipus japonicus'' and '' Scytothamnus australis''. In ''A. japonicus'', 5'-bromo- and 5'-chlorotetrafucol-A can also be detected. References Phlorotannins Natural phenol tetramers {{aromatic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ascophyllum Nodosum
''Ascophyllum nodosum'' is a large, common cold water seaweed or brown alga ( Phaeophyceae) in the family Fucaceae. Its common names include knotted wrack, egg wrack, feamainn bhuí, rockweed, knotted kelp and Norwegian kelp. It grows only in the northern Atlantic Ocean, along the north-western coast of Europe (from the White Sea to Portugal) including east Greenland and the north-eastern coast of North America. Its range further south of these latitudes is limited by warmer ocean waters. It dominates the intertidal zone. ''Ascophyllum nodosum'' has been used numerous times in scientific research and has even been found to benefit humans through consumption. Scientific name history ''Ascophyllum nodosum'' is the only species in the genus ''Ascophyllum''. The original name (basionym) was ''Fucus nodosus'' Linnaeus 1753. The species was transferred to the genus ''Ascophyllum'' (as ''Ascophylla'') by Stackhouse (Papenfuss 1950), under the name ''Ascophyllum laevigata'' (Guiry and G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Phenol
In biochemistry, naturally occurring phenols are natural products containing at least one phenol functional group. Phenolic compounds are produced by plants and microorganisms. Organisms sometimes synthesize phenolic compounds in response to ecological pressures such as pathogen and insect attack, UV radiation and wounding. As they are present in food consumed in human diets and in plants used in traditional medicine of several cultures, their role in human health and disease is a subject of research. Some phenols are germicidal and are used in formulating disinfectants. Classification Various classification schemes can be applied. A commonly used scheme is based on the number of carbons and was devised by Jeffrey Harborne and Simmonds in 1964 and published in 1980: C6-C7-C6 Diarylheptanoids are not included in this Harborne classification. They can also be classified on the basis of their number of phenol groups. They can therefore be called ''simple phenols'' or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phloroglucinol
Phloroglucinol is an organic compound with the formula C6H3(OH)3. It is a colorless solid. It is used in the organic synthesis, synthesis of pharmaceuticals and explosives. Phloroglucinol is one of three isomeric benzenetriols. The other two isomers are hydroxyquinol (1,2,4-benzenetriol) and pyrogallol (1,2,3-benzenetriol). Phloroglucinol, and its benzenetriol isomers, are still defined as "natural phenol, phenols" according to the IUPAC official nomenclature rules of chemical compounds. Many such monophenolics are often termed polyphenols. The enzyme is biosynthesized by phloroglucinol synthase. Synthesis and occurrence In 1855, phloroglucinol was first prepared from phloretin by the Austrian chemist Heinrich Hlasiwetz (1825–1875). A modern synthesis of phloroglucinol involves hydrolysis of benzene-1,3,5-triamine and its derivatives. Representative is the following route from 1,3,5-Trinitrobenzene, trinitrobenzene. : The synthesis is noteworthy because ordinary aniline deriv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tannin
Tannins (or tannoids) are a class of astringent, polyphenolic biomolecules that bind to and Precipitation (chemistry), precipitate proteins and various other organic compounds including amino acids and alkaloids. The term ''tannin'' is widely applied to any large polyphenolic compound containing sufficient hydroxyls and other suitable groups (such as carboxyls) to form strong complexes with various macromolecules. The term ''tannin'' (from scientific French ''tannin'', from French ''tan'' "crushed oak bark", ''tanner'' "to tan", cognate with English language, English ''tanning'', Medieval Latin ''tannare'', from Proto-Celtic ''*tannos'' "oak") refers to the abundance of these compounds in oak Bark (botany), bark, which was used in Tanning (leather), tanning animal Hide (skin), hides into leather. The tannin compounds are widely distributed in many species of plants, where they play a role in protection from predation (acting as pesticides) and might help in regulating plant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eckol
Eckol is a phlorotannin isolated from brown algae in the family Lessoniaceae such as species in the genus '' Ecklonia'' such as '' E. cava'' or '' E. kurome'' or in the genus '' Eisenia'' such as '' Eisenia bicyclis''. 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 antiplasmin inhibitory effect and a radioprotective effect in a mouse model. It also exhibits an ''in vitro'' cytoprotective effect against oxidative stress in Chinese hamster lung fibroblasts. It also shows antithrombotic An antithrombotic agent is a drug that reduces the formation of blood clots ( thrombi).http://cancerweb.ncl.ac.uk/cgi-bin/omd?antithrombotic Antithrombotics can be used therapeutically for prevention ( primary prevention, secondary prevention) or ... and profibrinolytic activities. References {{phlorotannin Phlorotannins Dibenzodioxins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vanillin–HCl Staining
Vanillin–HCl staining (10% vanillin and 90% of a mixture of ethanol and HCl, giving an orange color) can be used to visualize the localisation of tannins in cells. The localization of phlorotannins can be investigated by light microscopy after vanillin–HCl staining.Cytological studies on physodes in the vegetative cells of Cystoseira stricter Sauvagea (Phaeophyta, Fucales). Pellegrini L, J. Cell Sci., 1980, volume 41, pages 209–231 The phlorotannins can be seen this way in physodes in brown algae. The vanillin-HCl method can be used to estimate the proanthocyanidins content in plant cells, resulting in a red color of the test in the presence of catechin Catechin is a flavan-3-ol, a type of secondary metabolite providing antioxidant roles in plants. It belongs to the subgroup of polyphenols called flavonoids. The name of the catechin chemical family derives from ''catechu'', which is the tannic ... or proanthocyanidins. References Staining {{cell-biology-st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prussian Blue Assay
Prussian blue (also known as Berlin blue, Brandenburg blue, Parisian and Paris blue) is a dark blue pigment produced by oxidation of ferrous ferrocyanide salts. It has the chemical formula . It consists of cations, where iron is in the oxidation state of +3, and anions, where iron is in the oxidation state of +2, so, the other name of this salt is iron(III) hexacyanoferrate(II). Turnbull's blue is essentially identical chemically, excepting that it has different impurities and particle sizes—because it is made from different reagents—and thus it has a slightly different color. Prussian blue was created in the early 18th century and is the first modern synthetic pigment. It is prepared as a very fine colloidal dispersion, because the compound is not soluble in water. It contains variable amounts of other ions and its appearance depends sensitively on the size of the colloidal particles. The pigment is used in paints, it became prominent in 19th-century () Japanese wood ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ascorbic Acid
Ascorbic acid is an organic compound with formula , originally called hexuronic acid. It is a white solid, but impure samples can appear yellowish. It dissolves freely in water to give mildly acidic solutions. It is a mild reducing agent. Ascorbic acid exists as two enantiomers (mirror-image isomers), commonly denoted "" (for "levo") and "" (for "dextro"). The isomer is the one most often encountered: it occurs naturally in many foods, and is one form (" vitamer") of vitamin C, an essential nutrient for humans and many animals. Deficiency of vitamin C causes scurvy, formerly a major disease of sailors in long sea voyages. It is used as a food additive and a dietary supplement for its antioxidant properties. The "" form ( erythorbic acid) can be made by chemical synthesis, but has no significant biological role. Etymology The term ''ascorbic'' means antiscruvy and denotes the ability to fight off scurvy. It is related to combating Vitamin C deficiency. History The antiscor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glutaraldehyde
Glutaraldehyde is an organic compound with the formula . The molecule consists of a five carbon chain doubly terminated with formyl (CHO) groups. It is usually used as a solution in water, and such solutions exists as a collection of hydrates, cyclic derivatives, and condensation products, several of which interconvert. Because the molecule has two aldehyde functional groups, glutaraldehyde (and its hydrates) can crosslink substances with primary amine groups, through condensation. Crosslinking can rigidify and deactivate proteins and other molecules that are critical for normal biological function, such as DNA, and so glutaraldehyde solutions are effective biocides and fixatives. It is sold under the brandnames Cidex and Glutaral. As a disinfectant, it is used to sterilize surgical instruments. Uses Biochemistry Glutaraldehyde is used in biochemistry applications as an amine-reactive homobifunctional crosslinker and fixative. It kills cells quickly by crosslinking thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
