The bacterial degradation of flavonoids. Hydroxylation of the A-ring of taxifolin by a soil pseudomonad

Cell-free extracts prepared from a Pseudomonas sp. grown on (+)-catechin oxidized taxifolin in the presence of NAD(P)H and molecular oxygen. The enzyme catalysing the reaction was partially purified and shown to be a flavoprotein. The product was identified as 3',4',5,7,8-pentahydroxyflavanonol (dihydrogossypetin).