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 and is used as an ingredient in dietary supplements, beverages, and foods.
Flavonoids are synthesized by the phenylpropanoid metabolic pathway in which the amino acid phenylalanine is used to produce 4-coumaroyl-CoA. This can be combined with malonyl-CoA to yield the true backbone of flavonoids, a group of compounds called chalcones, which contain two phenyl rings. Conjugate ring-closure of chalcones results in the familiar form of flavonoids, the three-ringed structure of a flavone. The metabolic pathway continues through a series of enzymatic modifications to yield flavanones → dihydroflavonols → anthocyanins. Along this pathway, many products can be formed, including the flavonols, flavan-3-ols, proanthocyanidins (tannins) and a host of other various polyphenolics.
In enzymology, an agmatine N4-coumaroyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, an anthocyanin 5-O-glucoside 6'''-O-malonyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, an anthocyanin 6"-O-malonyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a flavonol-3-O-beta-glucoside O-malonyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, an indoleacetylglucose-inositol O-acyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, an isoflavone-7-O-beta-glucoside 6"-O-malonyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a sinapoylglucose---sinapoylglucose O-sinapoyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a flavanone 7-O-beta-glucosyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a flavone apiosyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a flavonol-3-O-glucoside glucosyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a flavonol-3-O-glucoside L-rhamnosyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a flavonol 3-O-glucosyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a flavonol-3-O-glycoside glucosyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a flavonol 7-O-beta-glucosyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a sterol 3beta-glucosyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a beta-glucoside kinase is an enzyme that catalyzes the chemical reaction
Coumaroyl-coenzyme A is the thioester of coenzyme-A and coumaric acid. Coumaroyl-coenzyme A is a central intermediate in the biosynthesis of myriad natural products found in plants. These products include lignols, flavonoids, isoflavonoids, coumarins, aurones, stilbenes, catechin, and other phenylpropanoids.
The biosynthesis of phenylpropanoids involves a number of enzymes.
