Characterization of new bacterial transformation products of 1,1,1-trichloro-2,2-bis-(4-chlorophenyl) ethane (DDT) by gas chromatography/mass spectrometry.
The microbial transformation of DDT, DDD and DDE was studied in Gram-negative strain B-206 and a number of phenolic metabolites were identified as the trimethylsilyl derivatives in the bacterial extracts by gas chromatography/mass spectrometry. The major metabolites of DDT were DDD, DDE, DDMU, 1,1,1-trichloro-2-(2-hydroxy-4-chlorophenyl)-2-(4'-chlorophenyl) ethane, 1,1,1-trichloro-2-(2-hydroxy-4-chlorophenyl)-2-(4'-hydroxyphenyl) ethane, and 1,1,1-trichloro-2,2-bis-(2-hydroxy-4-chlorophenyl) ethane. Conversely, DDD was mainly degraded into DDE, 1,1-dichloro-2-(2-hydroxy-4-chlorophenyl)-2-(4'-chlorophenyl) ethane and 1,1-dichloro-2-(2-hydroxy-4-chlorophenyl)-2-(4'-hydroxyphenyl) ethane. Finally, DDE was transformed into DDMU, 1,1-dichloro-2-(2-hydroxy-4-chlorophenyl)-2-(4'-chlorophenyl) ethylene, 1,1-dichloro-2-(2-hydroxy-4-chlorophenyl)-2-(4'hydroxyphenyl) ethylene and 1-chloro-2-(2-hydroxy-4-chlorophenyl)-2-(4'-chlorophenyl) ethylene. The phenolic metabolites exhibited [M - TMSCl]+., [M - HCl - TMSCl]+. and/or [M - HCl - TMSCl - Me]+ fragment ions which reflect the presence of an ortho hydroxyl group in these molecules. Other mass spectral features used to determine their structure are presented and a metabolic scheme accounting for their formation is proposed.
Massé
R
R
Institut National de la Recherche Scientifique, Université du Québec Canada.
Lalanne
D
D
Messier
F
F
Sylvestre
M
M
D001419:Bacteria / Q000378:metabolism*; D001673:Biodegradation, Environmental; D001711:Biotransformation; D003634:DDT / Q000031:analogs & derivatives / Q000378:metabolism*; D003633:Dichlorodiphenyl Dichloroethylene / Q000032:analysis / Q000378:metabolism; D003632:Dichlorodiphenyldichloroethane / Q000032:analysis / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000378:metabolism; D014297:Trimethylsilyl Compounds / Q000378:metabolism
D014297:Trimethylsilyl Compounds; D003633:Dichlorodiphenyl Dichloroethylene; D003634:DDT; D003632:Dichlorodiphenyldichloroethane