Cytochrome P-450 from Tulip Bulbs (Tulipa fosteriana L.) Oxidizes an Azo Dye Sudan I (1-Phenylazo-2-hydroxynaphthalene, Solvent Yellow 14) in vitro

Abstract

The microsomal fraction from tulip bulbs (Tulipa fosteriana L.) contains cytochrome P-450 enzymes catalyzing the NADPH-dependent oxidation of the xenobiotic substrate, an azo dye Sudan I (1-phenylazo-2-hydroxynaphthalene, Solvent Yellow 14). C-Hydroxy derivatives [1-(4-hydroxyphenylazo)-2-hydroxynaphthalene, 1-phenylazo-2,6-dihydroxynaphthalene, 1-(4-hydroxyphenylazo)-2,6-dihydroxynaphthalene] and the benzenediazonium ion are the products of the Sudan I oxidation. The oxidation of Sudan I has also been assessed in a reconstituted electron-transport chain with the isolated cytochrome P-450, isolated plant NADPH-cytochrome P-450 reductase and phospholipid. The results are discussed from the point of view of the role of cytochromes P-450 in the metabolism of xenobiotics in plants.