Flavonolignans are natural phenols composed of a part flavonoid and a part phenylpropane.
Flavonolignans identified in Silybum marianum (milk thistle) silymarin complex include silibinin, silychristin, silydianin, dehydrosilybin, deoxysilycistin, deoxysilydianin, silandrin, silybinome, silyhermin and neosilyhermin and can be produced in vitro. [1] Silibinin is found in the roots of S. marianum [2] while silyamandin [3] can be found in the fruit. [4]
Hydnocarpin can be found naturally in Onopordon corymbosum [5] and can be synthesised. [6]
Scutellaprostin A, B, C, D, E and F can be isolated from Scutellaria prostrata and can also be synthesized. [7]
Hydnowightin can be isolated from Hydnocarpus wightianus seeds. [8]
Three flavonolignans derived from the flavone tricin have been isolated from the herb Avena sativa . [9]
Palstatin has been isolated from the Amazon tree Hymeneae palustris . [10]
Salcolin A and salcolin B can be found in Salsola collina . [11]
Rhodiolin, the product of the oxidative coupling of coniferyl alcohol with the 7,8-dihydroxy grouping of the flavonol herbacetin, can be found in the rhizome of Rhodiola rosea . [12]
The flavonolignans tricin 4'-O-(erythro-beta-guaiacylglyceryl) ether and tricin 4'-O-(threo-beta-guaiacylglyceryl) ether can be isolated together with their 7-O-glucosides in the leaves of Hyparrhenia hirta . [13]
A 2022 research has concluded that flavonolignans "reduce the virulence of antibiotic-resistant bacterial strains". [14]
Rhodiola rosea is a perennial flowering plant in the family Crassulaceae. It grows naturally in wild Arctic regions of Europe, Asia, and North America, and can be propagated as a groundcover.
Silibinin (INN), also known as silybin (both from Silybum, the generic name of the plant from which it is extracted), is the major active constituent of silymarin, a standardized extract of the milk thistle, containing a mixture of flavonolignans consisting of silibinin, isosilibinin, silychristin, silidianin, and others. Silibinin itself is a mixture of two diastereomers, silybin A and silybin B, in approximately equimolar ratio. Silibinin is used in pure forms as a medication, and more frequently as an active ingredient in milk thistle–derived herbal supplements.
Silybum marianum is a species of thistle. It has various common names including milk thistle, blessed milkthistle, Marian thistle, Mary thistle, Saint Mary's thistle, Mediterranean milk thistle, variegated thistle and Scotch thistle. This species is an annual or biennial plant of the family Asteraceae. This fairly typical thistle has red to purple flowers and shiny pale green leaves with white veins. Originally a native of Southern Europe through to Asia, it is now found throughout the world.
Apigenin (4′,5,7-trihydroxyflavone), found in many plants, is a natural product belonging to the flavone class that is the aglycone of several naturally occurring glycosides. It is a yellow crystalline solid that has been used to dye wool.
Phenanthrenoids are chemical compounds formed with a phenanthrene backbone. These compounds occur naturally in plants, although they can also be synthesized.
Tricin is a chemical compound. It is an O-methylated flavone, a type of flavonoid. It can be found in rice bran and sugarcane.
Taxifolin (5,7,3',4'-flavan-on-ol), also known as dihydroquercetin, belongs to the subclass flavanonols in the flavonoids, which in turn is a class of polyphenols. It is extracted from plants such as Siberian larch and milk thistle.
Dihydrokaempferide is a flavanonol, a type of flavonoid. It can be found in Prunus domestica, in the wood of Salix caprea and in the Brazilian green propolis.
A type proanthocyanidins are a specific type of proanthocyanidins, which are a class of flavonoid. Proanthocyanidins fall under a wide range of names in the nutritional and scientific vernacular, including oligomeric proanthocyanidins, flavonoids, polyphenols, condensed tannins, and OPCs. Proanthocyanidins were first popularized by French scientist Jacques Masquelier.
The O-methylated flavonoids or methoxyflavonoids are flavonoids with methylations on hydroxyl groups. O-methylation has an effect on the solubility of flavonoids.
Afzelechin is a flavan-3-ol, a type of flavonoid. It can be found in Bergenia ligulata. It exists as at least 2 major epimers.
Selliguea feei is a fern belonging to the genus Selliguea in the family Polypodiaceae. This fern can be collected in Indonesia. The species name feei commemorates the botanist Antoine Laurent Apollinaire Fée.
Epicatechin gallate (ECG) is a flavan-3-ol, a type of flavonoid, present in green tea. It is also reported in buckwheat and in grape.
Prenylated flavonoids or prenylflavonoids are a sub-class of flavonoids. They are widely distributed throughout the plant kingdom. Some are known to have phytoestrogenic or antioxidant properties. They are given in the list of adaptogens in herbalism. Chemically they have a prenyl group attached to their flavonoid backbone. It is usually assumed that the addition of hydrophobic prenyl groups facilitate attachment to cell membranes. Prenylation may increase the potential activity of its original flavonoid.
Herbacetin is a flavonol, a type of flavonoid.
Ombuin is an O-methylated flavonol, a type of flavonoid. It is the 4',7-O-methyl derivative of quercetin.
Patuletin is an O-methylated flavonol. It can be found in the genus Eriocaulon.
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.
Affinisine is a monoterpenoid indole alkaloid which can be isolated from plants of the genus Tabernaemontana. Structurally, it can be considered a member of the sarpagine alkaloid family and may be synthesized from tryptophan via a Pictet-Spengler reaction.
Silychristin is a natural product and one of the constituents of silymarin, the standardized, active extract of the fruit of milk thistle, Silybum marianum. It is the second most abundant constituent in silymarin, after silybin. Silychristin is a flavonolignan, along with many other silymarin constituents, meaning it is composed up of a flavonoid and a lignan. It is estimated that up to 65–80% of silymarin extract is made up of flavonolignans, like silychristin, which give silymarin its well known potent antioxidant and hepatoprotective properties. Silychristin can exist as two stereoisomers, silychristin A and silychristin B. The marianum variety of S. marianum includes silychristin A as a major flavonolignan constituent, while the lesser known and studied albiflorum variety includes unique flavonolignans, including silyhermin, (–)-silandrin, and (+)-silymonin.