Pterocarpan 6a-Hydroxylase

Pterocarpan 6a-hydroxylase (3,9-dihydroxypterocarpan 6a-hydroxylase) P6aH (DH6aH) 1.14.13.28 CytP450 (CYP93A) 202... 

Scheme 1.1 Pathway for the biosynthesis of the major classes of flavonoids. 1, Chalcone synthase 2, chalcone isomerase 3, flavone synthase 4, flavanone 3-hydroxylase 5, flavonol synthase 6, dihydroflavonol reductase 7, anthocyanidin synthase 8, anthocyanidin glucosyltransferase 9, chalcone-ketide reductase 10, chalcone isomerase 11, isoflavone synthase 12, isoflavone 2 -hydroxylase 13, isoflavone reductase 14, pterocarpan synthase 15, pterocarpan 6a-hydroxylase 16, prenyltransferase 17, prenylcyclase.

An additional enzyme, 6a-hydroxylase, is responsible for the formation of many pterocarpan derivatives (Barz and Welle, 1992 Heller and Forkmann, 1988). 6a-Hydroxypter-ocarpans [such as (-)-pisatin (101) and 6a,lla-dehydropt-erocarpan derivatives are well-known antifungal compounds (see the section on phytoalexins, below). 

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