Isoflavonoid Biosynthesis https://www.kegg.jp/kegg-bin/highlight_pathway?scale=1.0&map=map00943&keyword=flavonoids Isoflavonoids are biologically active compounds, such as phytoestrogens, produced by pea family plants. While flavonoids (in the narrow sense) have the 2- phenylchromen-4-one backbone, isoflavonoids have the 3-phenylchromen-4-one backbone with no hydroxyl group substitution at position 2. Isoflavonoids are derived from the flavonoid biosynthesis pathway via liquiritigenin or naringenin. (Flavonoid Biosynthesis) -> [1,2] 1) Liquiritigenin -> [1,2,3] 1) flavone synthesis I & II -> 7,4’Dihydroxyflavone OR 2) flavonoid 6-hydroxylase -> 6,7,4’-Trihydroxyflavanone -> 2- hydroxyisoflavone synthase -> 2,6,7,4’-tetrahydroxyisoflavanone -> 6- Hydroxydaidzein -> Glycitein -> isoflavone 7-O-glucosyltransferase -> Glycitein 7-O-glucoside -> isoflavone 7-O-glucoside-6’’-O-malonyltransferase -> Glycitein 7-O-glucoside-6”-O-malonate OR 3) 2-hydroxyisoflavanone synthase -> 2,7,4’Trihydroxyisoflavanone -> [1,2] 1) Feedback Loop 2,7,4’-trihydroxyisoflavanone 4’-O-methyltransferase / isoflavone 4’-O-methyltransferase -> 2,7-Dihydroxy-4’-methoxyisoflavanone -> 2- hydroxyisoflavanone dehydratase -> Formononetin OR 2) 2-hydroxyisoflavone dehydratase -> Daidzein -> [1,2,3,4,5] 1) isoflavone/4’-methoxyisoflavone 2’-hydroxylase -> 2’Hydroxydaidzein -> 2’Hydroxydaidzein reductase -> 2’-Hydroxydihydrodaidzein -> 3,9-Dihydroxypterocarpan -> 3,9-dihydroxypterocarpan 6a-monooxygenase -> 3,6,9- Trihydroxypterocarpan -> [1,2] 1) trihydroxypterocarpan dimethylallyltransferase -> 4-Glyceollidin -> glyceollin synthase -> (-)-Glyceollin I OR 2) trihydroxypterocarpan dimethylallyltransferase -> Glyceocarpin -> [1,2] 1) glyceollin synthase -> Glyceollin II OR 2) glyceollin synthase -> Glyceollin III OR 2) Anhydroglycinol -> Coumestrol OR 3) isoflavone-7-O-methyltransferase -> Isoformononetin OR 4) 2,7,4’-trihydroxyisoflavanone 4’-O-methyltransferase / isoflavone 4’_O- methyltransferase -> Formononetin -> [1,2,3] 1) isoflavone 7-O- glucosyltransferase -> Ononin -> isoflavone 7-O-glucoside-6’’-O- malonyltransferase -> Formononetin 7-O-glucoside-6’’-O-malonate -> Feedback loop -> Ononin -> Formononetin OR 2) isoflavone/4’-methoxyisoflavone 2’hydroxylase -> 2’-Hydroxyformononetin -> [1,2] 1) 7-Hydroxy-2’,4’,5’-trimethoxyisoflavone -> 9- Demethylmunduserone OR 2) 2’-hydroxyisoflavone reductase -> (-)-vestitone -> vestitone reductase -> 7,2’-Dihydroxy-4’-methoxy-isoflavanol -> pterocarpan synthase -> Medicarpin -> [1,2] 1) pterocarpan reductase -> (-)-Vestitol OR 2) isoflavone 7-O-glucosyltransferase -> (-)-Medicocarpin -> isoflavone 7-O- glucoside-6’’-O-malonyltransferase -> Medicarpin 3-O-glucoside-6’-malonate -> Hansford Boutchyard IV www.phytpharma.com 2/24/21 Feedback Loop -> (-)-Medicocarpin -> Medicarpin OR 3) isoflavone 3’hydroxylase -> Calycosin -> [1,2] 1) Rotenone OR 2) pseudobaptigenin synthase -> Pseudobaptigenin -> isoflavone/4’-methoxyisoflavone 2’-hydroxylase -> 2’,7- Dihydroxy-4’,5’-methylenedioxyflavone -> [1,2] 1) 2’-hydroxyisoflavone reductase -> (+)-Sophorol -> (+)-Maackiain -> (+)-6a-Hydroxy-maackiain -> (+)-6a- hydroxymaackianin 3-O-methyltransferase -> Pisatin OR 2) 2’-hydroxyisoflavone reductase -> (-)-Sophorol -> (-)Maackiain -> isoflavone 7-O-glucosyltransferase - > Trifolirhizin -> isoflavone 7-O-glucoside-6’’-O-malonyltransferase -> (-)- Maackiain-3-O-glucosyl-6’’-O-malonate -> Feedback Loop -> Trifolirhizin -> (- )Maackiain OR 5) isoflavone 7-O-glucosyltransferase -> Daidzin -> isoflavone 7-O-glucoside- 6’’-O-malonyltransferase -> Malonyldaidzin OR 2) Naringenin -> [1,2] 1) flavone synthase I & II -> Apigenin OR 2) 2-hydroxyisoflavanone synthase -> 2-Hydroxy-2,3-dihydrogenistein -> 2- hydroxyisoflavanone dehydratase -> Genistein -> [1,2,3,4] 1) isoflavone/4’-methoxyisoflavone 2’-hydroxylase -> 2’- Hydroxygenistein OR 2) isoflavone-7-O-methyltransferase -> Prunetin OR 3) 2,7,4’-trihydroxyisoflavone 4’-O-methyltransferase / isoflavone 4’-O- methyltransferase -> Biochanin A -> [1,2,3,4] 1) biochanin-A reductase -> dihydrobiochanin A OR 2) isoflavone 7-O-glucosyltransferase -> Biochanin A-beta- D-glucoside -> isoflavone 7-O-glucoside-6’’-O-malonyltransferase -> Biochanin A 7-O-(6-O-malonyl-beta-D-glucoside) OR 3) isoflavone 3’-hydroxylase -> Pratensein -> pseudobaptigenin synthase -> 5-Hydroxypseudobaptigenin OR 4) isoflavone/4’- methoxyisoflavone 2’-hydroxylase -> 2’-hydroxybiochanin A OR 4) isoflavone 7-O-glucosyltransferase -> Genistein 7-O-beta-D-glucoside -> isoflavone 7-O-glucoside-6’’-O-malonyltransferase -> Malonylgenistin Hansford Boutchyard IV www.phytpharma.com 2/24/21.