Ueber den abbau von flavonolen durch pflanzliche peroxidasen

Peroxidases have been shown to catalyse the degradation of flavonols via 2,3-dihydroxyflavanones to benzoic acids. Incubation of (U-¹⁴C)-kaempferol with pure horseradish peroxidase leads to the same reaction products (2,3,4,5,7,4′-pentahydroxyflavanone, p-hydroxybenzoic acid, ¹⁴CO₂, several polar, water soluble catabolites as given by enzyme preparations from various plant species. Further reactions of flavonols and their glycosides with peroxidases are discussed. All peroxidase isoenzymes of Sinapis alba and Cicer arietinum, obtained by isoelectric focusing, have been shown to degrade flavonols at the same rate. The peroxidase catalysed degradation of polyphenols is discussed in relation to IAA oxidase.