enzymology Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

, a flavonoid 3'-monooxygenase (, was wrongly classified as in the past) is an

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

that catalyzes the

chemical reaction A chemical reaction is a process that leads to the IUPAC nomenclature for organic transformations, chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the pos ...

:a flavonoid + NADPH + H⁺ + O₂

\rightleftharpoons

a 3'-hydroxyflavonoid + NADP⁺ + H₂O The 4 substrates of this enzyme are

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 ...

NADPH Nicotinamide adenine dinucleotide phosphate, abbreviated NADP or, in older notation, TPN (triphosphopyridine nucleotide), is a cofactor used in anabolic reactions, such as the Calvin cycle and lipid and nucleic acid syntheses, which require NAD ...

, H⁺, and O₂, whereas its 3

products Product may refer to: Business * Product (business), an item that serves as a solution to a specific consumer problem. * Product (project management), a deliverable or set of deliverables that contribute to a business solution Mathematics * Produ ...

are 3'-hydroxyflavonoid, NADP⁺, and H₂O. This enzyme belongs to the family of

oxidoreductase In biochemistry, an oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule, the reductant, also called the electron donor, to another, the oxidant, also called the electron acceptor. This group of enzymes usually ut ...

s, specifically those acting on paired donors, with O₂ as

oxidant An oxidizing agent (also known as an oxidant, oxidizer, electron recipient, or electron acceptor) is a substance in a redox chemical reaction that gains or " accepts"/"receives" an electron from a (called the , , or ). In other words, an oxid ...

and incorporation or reduction of oxygen. The oxygen incorporated need not be derived from O₂ with NADH or NADPH as one donor, and incorporation of one atom of oxygen into the other donor. The

systematic name A systematic name is a name given in a systematic way to one unique group, organism, object or chemical substance, out of a specific population or collection. Systematic names are usually part of a nomenclature. A semisystematic name or semitrivial ...

of this enzyme class is flavonoid,NADPH:oxygen oxidoreductase (3'-hydroxylating). Other names in common use include flavonoid 3'-hydroxylase, flavonoid 3-hydroxylase (erroneous), NADPH:flavonoid-3'-hydroxylase, and flavonoid 3-monooxygenase (erroneous). This enzyme participates in

flavonoid biosynthesis 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 ...

References

EC 1.14.14 NADPH-dependent enzymes Enzymes of unknown structure Flavonoids metabolism {{1.14-enzyme-stub