Formononetin is an O-methylated isoflavone. It is found in a number of plants and herbs like the red clover

Red clover

Trifolium pratense is a species of clover, native to Europe, Western Asia and northwest Africa, but planted and naturalised in many other regions....

. Along with other phytoestrogens

Phytoestrogens

Phytoestrogens are plant-derived xenoestrogens functioning as the primary female sex hormone not generated within the endocrine system but consumed by eating phytoestrogonic plants...

, it predominantly occurs in leguminous plants and Fabaceae

Fabaceae

The Fabaceae or Leguminosae, commonly known as the legume, pea, or bean family, is a large and economically important family of flowering plants. The group is the third largest land plant family, behind only the Orchidaceae and Asteraceae, with 730 genera and over 19,400 species...

, particularly in beans, such as green beans, lima beans, soy and many others, as the free aglycone

Aglycone

An aglycone is the non-sugar compound remaining after replacement of the glycosyl group from a glycoside by a hydrogen atom. The spelling aglycon is sometimes encountered .Classes of phytochemicals found in the aglycone and glycosides forms :...

 or in form of its glucoside

Glucoside

A glucoside is a glycoside that is derived from glucose. Glucosides are common in plants, but rare in animals. Glucose is produced when a glucoside is hydrolysed by purely chemical means, or decomposed by fermentation or enzymes....

 ononin

Ononin

Ononin is one of several known isoflavones. Ononin is found in a number of plants and herbs like soybean and from Glycyrrhiza uralensis .Ononin is the 7-O-glucoside of formononetin....

.

Metabolism

The enzyme 4'-methoxyisoflavone 2'-hydroxylase

4'-methoxyisoflavone 2'-hydroxylase

In enzymology, a 4'-methoxyisoflavone 2'-hydroxylase is an enzyme that catalyzes the chemical reactionThe 4 substrates of this enzyme are formononetin, NADPH, H+, and O2, whereas its 3 products are 2'-hydroxyformononetin, NADP+, and H2O....

 uses formononetin, NADPH, H⁺, and O₂ to produce 2'-hydroxyformononetin, NADP⁺ and H₂O.

The enzyme Isoflavone 3'-hydroxylase

Isoflavone 3'-hydroxylase

In enzymology, an isoflavone 3'-hydroxylase is an enzyme that catalyzes the chemical reactionThe 4 substrates of this enzyme are formononetin, NADPH, H+, and O2, whereas its 3 products are calycosin, NADP+, and H2O....

 uses formononetin, NADPH, H⁺, and O₂ to produce calycosin

Calycosin

Calycosin is a O-methylated isoflavone. It can be isolated from Astragalus membranaceus Bge. var. mongholicus and Trifolium pratense .-Biosynthesis:...

(3'-hydroxyformononetin), NADP⁺ and H₂O.