Formononetin

Natural occurrences

Formononetin is found in a number of plants and herbs like the red clover. Along with other phytoestrogens, it predominantly occurs in leguminous plants and Fabaceae, particularly in beans, such as green beans, lima beans, soy and many others, as the free aglycone or in form of its glucoside ononin.

It can also be found in Maackia amurensis cell cultures.

Metabolism

The enzyme 4'-methoxyisoflavone 2'-hydroxylase uses formononetin, NADPH, H⁺, and O₂ to produce 2'-hydroxyformononetin, NADP⁺ and H₂O.

The enzyme Isoflavone 3'-hydroxylase uses formononetin, NADPH, H⁺, and O₂ to produce calycosin (3'-hydroxyformononetin), NADP⁺ and H₂O.

Glycosides

Ononin is the 7-O-glucoside of formononetin.