Isorhamnetin is an
O-methylated flavon-ol from the class of
flavonoid
Flavonoids (or bioflavonoids; from the Latin word ''flavus'', meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans.
Chemically, flavonoids ...
s. A common food source of this 3'-methoxylated derivative of quercetin and its glucoside conjugates are pungent yellow or red onions, in which it is a minor pigment, quercetin-3,4'-diglucoside and quercetin-4'-glucoside and the aglycone quercetin being the major pigments. Pears, olive oil, wine and tomato sauce are rich in isorhamnetin. Others sources include the spice, herbal medicinal and
psychoactive
A psychoactive drug, psychopharmaceutical, psychoactive agent or psychotropic drug is a chemical substance, that changes functions of the nervous system, and results in alterations in perception, mood, consciousness, cognition or behavior.
...
Mexican tarragon ''(
Tagetes lucida
''Tagetes lucida'' is a perennial plant native to Mexico and Central America. It is used as a medicinal plant and as a culinary herb. The leaves have a tarragon-like scent, with hints of anise, and it has entered the nursery trade in Nort ...
)'', which is described as accumulating isorhamnetin and its 7-O-glucoside derivate. Nopal (Opuntia ficus-indica (L.)) is also a good source of isorhamnetin, which can be extracted by
supercritical fluid extraction Supercritical fluid extraction (SFE) is the process of separating one component (the extractant) from another (the matrix) using supercritical fluids as the extracting solvent. Extraction is usually from a solid matrix, but can also be from liquids. ...
assisted by enzymes.
Metabolism
The enzyme
quercetin 3-O-methyltransferase uses
S-adenosyl methionine
''S''-Adenosyl methionine (SAM), also known under the commercial names of SAMe, SAM-e, or AdoMet, is a common cosubstrate involved in methyl group transfers, transsulfuration, and aminopropylation. Although these anabolic reactions occur throug ...
and
quercetin
Quercetin is a plant flavonol from the flavonoid group of polyphenols. It is found in many fruits, vegetables, leaves, seeds, and grains; capers, red onions, and kale are common foods containing appreciable amounts of it. It has a bitter flavor ...
to produce
S-adenosylhomocysteine and isorhamnetin.
The enzyme
3-methylquercetin 7-O-methyltransferase uses S-adenosyl methionine and 5,7,3',4'-tetrahydroxy-3-methoxyflavone (isorhamnetin) to produce S-adenosylhomocysteine and 5,3',4'-trihydroxy-3,7-dimethoxyflavone (
rhamnazin).
Glycosides
*
Isorhamnetin-3-O-rutinoside-7-O-glucoside
*
Isorhamnetin-3-O-rutinoside-4'-O-glucoside
*
Narcissin (
Isorhamnetin-3-O-rutinoside)
See also
*
List of antioxidants in food
This is a list of antioxidants naturally occurring in food. Vitamin C and vitamin E – which are ubiquitous among raw plant foods – are confirmed as dietary antioxidants, whereas vitamin A becomes an antioxidant following metabolism ...
*
List of phytochemicals in food
While there is ample evidence to indicate the health benefits of diets rich in fruits, vegetables, legumes, whole grains and nuts, no specific food has been acknowledged by scientists and government regulatory authorities as providing a health bene ...
*
Tamarixetin, the 4'-methyl analog
References
External links
Isorhamnetin on chemblink.com
{{flavonol
O-methylated flavonols
Resorcinols