Effects of Flavonoids on 14 C[7,10]-Benzo[a]pyrene Degradation in Root Zone Soil

Secondary plant metabolites, such as flavonoids, may have an important role in developing organic contaminant- degrading enzymes; however, the effects are complicated. The addition of morin (a naturally occurring hydroxylated flavonoid) and flavone (a synthetic nonhydroxylated flavonoid) at concentrations greater than 10 µmol/L hindered ¹⁴C-B[a]P mineralization in root zone soil slurries. The reduction of ¹⁴CB[ a]P mineralization was accompanied by a decreased solvent (ethyl acetate) extractability of the remaining ¹⁴C-B[a]P and/or metabolites in the flavone-amended soil. In contrast, the solvent extractability of ¹⁴C did not change in morin-amended soil. ¹⁴C-B[a]P that remained in soil was not soluble into the water phase. The possible mechanisms of morin and flavone inhibition to B[a]P degradation are discussed.