Initial Steps in the Degradation of Methoxychlor by the White Rot Fungus Phanerochaete chrysosporium

The white rot fungus Phanerochaete chrysosporium mineralized [ring-(sup14)C]methoxychlor [1,1,1-trichloro-2,2-bis(4-methoxyphenyl)ethane] and metabolized it to a variety of products. The three most prominent of these were identified as the 1-dechloro derivative 1,1-dichloro-2,2-bis(4-methoxyphenyl)ethane, the 2-hydroxy derivative 2,2,2-trichloro-1,1-bis(4-methoxyphenyl)ethanol, and the 1-dechloro-2-hydroxy derivative 2,2-dichloro-1,1-bis(4-methoxyphenyl)ethanol by comparison of the derivatives with authentic standards in chromatographic and mass spectrometric experiments. In addition, the 1-dechloro-2-hydroxy derivative was identified from its (sup1)H nuclear magnetic resonance spectrum. The 1-dechloro and 2-hydroxy derivatives were both converted to the 1-dechloro-2-hydroxy derivative by the fungus; i.e., there was no requirement that dechlorination precede hydroxylation or vice versa. All three metabolites were mineralized and are therefore likely intermediates in the degradation of methoxychlor by P. chrysosporium.