Identification of hydroxylated metabolites of 3,3',4,4'-tetrachlorobiphenyl and metabolic pathway in whole poplar plants.
Polychlorinated biphenyls (PCBs) can be metabolized to hydroxylated polychlorinated biphenyls (OH-PCBs) as reported in a number of animal studies. However, there are few studies on OH-PCBs in vivo in whole plants. In order to explore the formation of OH-PCBs in whole plants in detail, poplars (Populus deltoides×nigra, DN34) were exposed to 3,3',4,4'-tetrachlorobiphenyl (CB77) in hydroponic solution. Poplars are widely used in phytoremediation applications and the complete genome has been sequenced. In this research, a HPLC-MS method was developed to directly determine the hydroxylated metabolites of CB77 (OH-CB77s), avoiding the experimental errors introduced by derivatization pretreatments required by gas chromatography-based methods. Three potential hydroxylated metabolites of CB77, including 6-hydroxy-3,3',4,4'-tetrachlorobiphenyl (6OH-CB77), 5-hydroxy-3,3',4,4'-tetrachlorobiphenyl (5OH-CB77) and 4'-hydroxy-3,3',4,5'-tetrachlorobiphenyl (4'OH-CB79), were determined in poplar tissues. The major product, 6OH-CB77, was detected in the roots, bottom bark, bottom wood, middle bark and middle wood for the whole poplar plants, but the minor product, 5OH-CB77, was detected only in the poplar roots. The concentration of 6OH-CB77 was about 10 times greater than that of 5OH-CB77 in the roots. However, the major mammalian metabolite, 4'OH-CB79 was not detected in any of the samples. The results suggest that the hydroxylated metabolic pathway of CB77 is via an epoxide intermediate in poplar.
Zhai
Guangshu
G
Department of Civil and Environmental Engineering and IIHR Hydroscience and Engineering, The University of Iowa, Iowa City, IA 52242, USA.
Lehmler
Hans-Joachim
HJ
Schnoor
Jerald L
JL
D002853:Chromatography, Liquid; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000737:chemistry / Q000378:metabolism*; D006900:Hydroxylation; D053858:Metabolic Networks and Pathways; D011078:Polychlorinated Biphenyls / Q000737:chemistry / Q000378:metabolism*; D032107:Populus / Q000737:chemistry / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization
D004785:Environmental Pollutants; D011078:Polychlorinated Biphenyls; C028451:3,4,3',4'-tetrachlorobiphenyl