Vetter Walter, Turek Claudia, Marsh Göran, Gaus Caroline
Institute of Food Chemistry, University of Hohenheim, Garbenstr. 28, D-70599 Stuttgart, Germany.
Chemosphere. 2008 Sep;73(4):580-6. doi: 10.1016/j.chemosphere.2008.05.065. Epub 2008 Jul 17.
Marine mammals from Queensland, Australia, are bioaccumulating elevated concentrations of a range of polybrominated natural products. In this study, we detected three new polybrominated dimethoxybiphenyls (PBDMBs) in the blubber of selected marine mammal samples which were identified as 2,6'-dimethoxy-3,3',5-tribromobiphenyl (2,6'-diMeO-BB 36), 2,2'-dimethoxy-3,3'-dibromobiphenyl (2,2'-diMeO-BB 36), and 6,6'-dimethoxy-3,3'-dibromobiphenyl (6,6'-diMeO-BB 11). These three PBDMBs are structurally related to the known natural product 2,2'-dimethoxy-3,3',5,5'-tetrabromobiphenyl (2,2'-diMeO-BB 80). In the first part of this study, 2,2'-diMeO-BB 80 was photochemically debrominated under UV irradiation. This resulted in seven of eight possible mono- to triBDMBs as debromination products. In the second part of this study, the structure of all PBDMBs debromination products was investigated. This was supported by synthesis of two diBDMB and one triBDMB via bromination and subsequent methylation of 2,2'-biphenyldiol. Structures of the remaining PBDMBs were tentatively assigned by considering the retention times, mass spectra and amounts formed during UV irradiation of 2,2'-diMeO-BB 80 . In the third part of this study, blubber of marine mammals from Australia was analysed for PBDMBs using gas chromatography in combination with electron ionization mass spectrometry (GC/EI-MS) in the selected ion monitoring mode. In these samples, 2,2'-diMeO-BB 80 was found at concentrations of 200-1800ngg(-1) lipid weight (lw). The latter represents the highest concentration reported for this compound in environmental samples. 6,6'-diMeO BB 11, 2,2'-diMeO BB 36, and 2,6'-diMeO BB 36 were present at approximately 7ngg(-1) lipids, or 0.43-1.5% of diMeO-BB 80. No further PBDMBs were detected in the samples. The di- and triBDMBs identified in marine mammal blubber have not been reported as natural products. They may represent either new natural products or transformation products of 2,2'-diMeO-BB 80.
来自澳大利亚昆士兰的海洋哺乳动物体内正在生物累积一系列多溴化天然产物，且其浓度不断升高。在本研究中，我们在选定的海洋哺乳动物样本的鲸脂中检测到三种新的多溴二甲基联苯（PBDMBs），它们分别被鉴定为2,6'-二甲氧基-3,3',5-三溴联苯（2,6'-diMeO-BB 36）、2,2'-二甲氧基-3,3'-二溴联苯（2,2'-diMeO-BB 36）和6,6'-二甲氧基-3,3'-二溴联苯（6,6'-diMeO-BB 11）。这三种PBDMBs在结构上与已知的天然产物2,2'-二甲氧基-3,3',5,5'-四溴联苯（2,2'-diMeO-BB 80）相关。在本研究的第一部分，2,2'-diMeO-BB 80在紫外线照射下发生光化学脱溴反应。这产生了八种可能的单溴到三溴二甲基联苯中的七种作为脱溴产物。在本研究的第二部分，对所有PBDMBs脱溴产物的结构进行了研究。通过对2,2'-联苯二醇进行溴化和随后的甲基化反应合成了两种二溴二甲基联苯和一种三溴二甲基联苯，这为该研究提供了支持。通过考虑2,2'-diMeO-BB 80在紫外线照射过程中的保留时间、质谱和生成量，初步确定了其余PBDMBs的结构。在本研究的第三部分，采用气相色谱结合电子电离质谱（GC/EI-MS）的选定离子监测模式，对来自澳大利亚的海洋哺乳动物的鲸脂进行了PBDMBs分析。在这些样本中，发现2,2'-diMeO-BB 80的浓度为200 - 1800ng g(-1)脂质重量（lw）。后者代表了该化合物在环境样本中报道的最高浓度。6,6'-diMeO BB 11、2,2'-diMeO BB 36和2,6'-diMeO BB 36的含量约为7ng g(-1)脂质，即diMeO-BB 80的0.43 - 1.5%。样本中未检测到其他PBDMBs。在海洋哺乳动物鲸脂中鉴定出的二溴和三溴二甲基联苯尚未作为天然产物被报道。它们可能代表新的天然产物或2,2'-diMeO-BB 80的转化产物。
