2-hydroxyisoflavanone synthase (, CYT93C, IFS, isoflavonoid synthase) is an enzyme with systematic name liquiritigenin,NADPH:oxygen oxidoreductase (hydroxylating, aryl migration). It catalyses a rearrangement reaction which converts flavonoids into isoflavones, for example:
The product 2,4',7-trihydroxyisoflavanone is unstable and loses water, either spontaneously or by the action of 2-hydroxyisoflavanone dehydratase, giving daidzein.
The enzyme can also act on naringenin, leading to the isoflavone genistein.{
Isoflavonoid synthase is a cytochrome P450 protein containing heme. It requires a partner cytochrome P450 reductase for functional expression. This uses nicotinamide adenine dinucleotide phosphate (NADPH).