Oxidation of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) by Alcaligenes eutrophus A5.
Previous studies demonstrated that Alcaligenes eutrophus A5 transforms 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) to 4-chlorobenzoate via a meta-ring fission product. The initial reactions could be catalyzed by either monooxygenase or dioxygenase enzymes. In the present study, a transient intermediate that accumulated during the transformation of DDT by the biphenyl-grown cells was identified as 1,1,1-trichloro-2-(4-chlorophenyl-2,3-dihydro-4,6-cyclohexadiene)-2-(4'- chlorophenyl)ethane (DDT-2,3-dihydrodiol) on the basis of mass spectral analysis after n-butylboronic acid derivatization. The dihydrodiol undergoes a characteristic acid-catalyzed dehydration to produce phenols. 1H-NMR indicated a cis-relative stereochemistry. The results indicate that the biphenyl dioxygenase from A. eutrophus A5 catalyzes the dihydroxylation of DDT at the unsubstituted carbons on the aromatic ring to produce DDT-2,3-dihydrodiol.
Nadeau
L J
LJ
Armstrong Laboratory, AFRL-MLQR, 139 Barnes Drive, Suite 2, Tyndall Air Force Base, FL 32403-5323, USA.
Sayler
G S
GS
Spain
J C
JC
D000421:Alcaligenes / Q000378:metabolism*; D001673:Biodegradation, Environmental; D001713:Biphenyl Compounds / Q000737:chemistry; D003470:Culture Media / Q000737:chemistry; D003634:DDT / Q000378:metabolism*; D007306:Insecticides / Q000378:metabolism*; D013058:Mass Spectrometry; D010084:Oxidation-Reduction; D010105:Oxygenases / Q000302:isolation & purification / Q000378:metabolism; D019802:Succinic Acid / Q000737:chemistry; D014050:Toluene / Q000737:chemistry
D001713:Biphenyl Compounds; D003470:Culture Media; D003634:DDT; D007306:Insecticides; D010105:Oxygenases; D019802:Succinic Acid; D014050:Toluene; C010574:biphenyl