bde-208 and decabromobiphenyl-ether

In this study, the bioaccumulation and toxic effects of decabromodiphenyl ether (BDE209) (1 and 10 mg kg

Topics: Animals; Catalase; Gas Chromatography-Mass Spectrometry; Halogenated Diphenyl Ethers; Iron; Malondialdehyde; Nanoparticles; Oligochaeta; Oxidative Stress; Soil; Soil Pollutants; Superoxide Dismutase

Decabromodiphenyl ether (BDE209) is a ubiquitous persistent pollutant and has contaminated the environment worldwide. To accelerate BDE209 elimination and reveal the mechanism concerned, the biosurfactant tea saponin enhanced degradation of BDE209 by Brevibacillus brevis was conducted. The results revealed that tea saponin could efficiently increase the solubility of BDE209 in mineral salts medium and improve its biodegradation. The degradation efficiency of 0.5 mg L(-1) BDE209 by 1 g L(-1) biomass with surfactant was up to 55% within 5d. Contact time was a significant factor for BDE209 biodegradation. BDE209 biodegradation was coupled with bioaccumulation, ion release and utilization, and debromination to lower brominated PBDE metabolites. During the biodegradation process, B. brevis metabolically released Na(+), NH4(+), NO2(-) and Cl(-), and utilized the nutrient ions Mg(2+), PO4(3-) and SO4(2-). GC-MS analysis revealed that the structure of BDE209 changed under the action of strain and nonabromodiphenyl ethers (BDE-208, -207 and -206), octabromodiphenyl ethers (BDE-203, -197 and -196) and heptabromodiphenyl ether (BDE-183) were generated by debromination.

Topics: Biodegradation, Environmental; Brevibacillus; Environmental Pollutants; Flame Retardants; Gas Chromatography-Mass Spectrometry; Halogenated Diphenyl Ethers; Halogenation; Saponins; Surface-Active Agents; Tea

Polychaetes (Nereis succinea) were exposed to DE-83 contaminated sediments to investigate the bioaccumulation and bioavailability of nona- and deca-BDEs in sediment. All the major congeners in DE-83 were bioavailable to the lugworms. The uptake coefficients (K(s)) of nona- and deca-BDE congeners in lugworms were in the range of 0.18-0.65 (d(-1)), with the values of BDE-207 and -208 slightly higher than those of BDE-206 and -209. Elimination of nona- and deca-BDE congeners from lugworms was very fast. The estimated half-lives of nona- and deca-BDE congeners in the lugworms were at 0.7d. The bioavailability of nona- and deca-BDE congeners was very low, with BSAF of 0.017 for BDE-206 and -209 and 0.054 for BDE-207 and -208. These may be due to the large molecular size and high affinity of PBDEs to sediment particles. The contribution of BDE-206 in the profile of nona-BDEs in lugworm tissue decreased with exposure time while those of BDE-207 and -208 increased, which could be the result of the biotransformation of BDE-209 to BDE-207 and -208.

Topics: Animals; Biotransformation; Geologic Sediments; Halogenated Diphenyl Ethers; Polychaeta; Water Pollutants, Chemical

Polybrominated diphenyl ethers (PBDEs) have been used extensively as brominated flame retardants (BFRs) in textiles, upholstery and electronics. They are ubiquitous contaminants in wildlife and humans. A low concentration of nonabrominated diphenyl ethers (nonaBDEs) is present in commercial DecaBDE and they are also abiotic and biotic debromination products of decabromodiphenyl ether (BDE-209). The objective of the present work was to develop methods for synthesis of the three nonaBDEs, 2,2',3,3',4,4',5,5',6-nonabromodiphenyl ether (BDE-206), 2,2',3,3',4,4',5,6,6'-nonabromodiphenyl ether (BDE-207) and 2,2',3,3',4,5,5',6,6'-nonabromodiphenyl ether (BDE-208), with the intention of making them available as authentic standards for analytical, toxicological and stability studies, as well as studies regarding physical-chemical properties. Two methods were developed, one based on perbromination of phenoxyanilines and the other via reductive debromination of BDE-209 by sodium borohydride followed by chromatographic separation of the three nonaBDE isomers formed. An additional nonabrominated compound, 4'-chloro-2,2',3,3',4,5,5',6,6'-nonabromodiphenyl ether (Cl-BDE-208), was also synthesized in the present work. Cl-BDE-208, prepared by the perbromination of 4-chlorodiphenyl ether, may be used as an internal standard in analysis of highly brominated diphenyl ethers. BDE-206, BDE-207, BDE-208 and Cl-BDE-208 were characterized by 1H NMR, 13C NMR, electron ionization mass spectra and by their melting points. The structures of all three nonaBDEs have been characterized previously by X-ray crystallography.

Topics: Chemistry, Organic; Crystallography, X-Ray; Flame Retardants; Halogenated Diphenyl Ethers; Magnetic Resonance Spectroscopy; Molecular Structure; Phenyl Ethers; Polybrominated Biphenyls