Novel Natural and Synthetic Organobromine Compounds in the Environment: Toxic or Therapeutic?

有机溴化合物可以是天然的，也可以是合成的。溴化阻燃剂(BFR)，如多溴联苯醚(PBDEs)和多溴联苯(PBBS)，因其产量大、用途广泛、在环境中普遍存在以及毒性大而备受关注。水生生态系统中羟化和甲氧基化多溴二苯醚的浓度往往大于多溴二苯醚的浓度。合成的BRP也已被生产并被广泛用作阻燃剂。在逐步淘汰多溴二苯醚配方的同时，多达75种新的合成溴化阻燃剂正在被取代。预计这些新化合物将开始进入环境。除了环境中已知的合成溴(BR)化合物外，环境中还存在一些未鉴定的有机溴(OBR)。虽然已经在一些环境样品中对EOBrs进行了研究，但很少有研究确定EOBrs的可识别比例，以及EOBrs由天然产品或合成化合物组成的比例。初步研究表明，环境样品中可提取的有机溴化合物(EOBR)和总溴(TBR)的可鉴别率不到1%。拟议的研究将：1)在一系列海洋和淡水生物中鉴定和量化新的EOBrs；2)使用质量平衡(On BR)方法来确定可能存在哪些额外的EOBrs；已经开发了基于分子大小和极性的TBR、EOBR和五类已识别EOBrs的提取和清理方法，并将应用该方法，以便可以应用适当的后续鉴定程序；3)使用生物测定来确定新型EOBrs的毒性和潜在的有益影响，以确定：1)它们的毒性作用模式和作用阈值，以及2)它们作为治疗剂的潜力。如果化合物被确定为毒性太大，将不会对它们的治疗特性进行进一步测试。

Organobromine compounds can be natural or synthetic. Brominated flame retardants (BFRs), such as polybrominated diphenyl ethers (PBDEs) and polybrominated biphenyls (PBBs) are of concern due to high production volume, widespread use, ubiquitous occurrence in the environment, and toxicity. Concentrations of hydroxylated and methoxylated PBDEs in aquatic ecosystems are often greater than those of PBDEs. Synthetic BRPs have also been produced and widely used as flame retardants. While PBDE formulations are being phased out, as many as 75 new classes of synthetic BFRs are being substituted. It is expected that these new compounds will begin to enter the environment. In addition to the known synthetic bromine (Br)-containing compounds in the environment, there are a number of unidentified organobromine (OBrs) in the environment. While EOBrs have been investigated in some environmental samples, few studies have determined the proportion of EOBr that can be identified and what proportion of EOBr is composed of natural products or synthetic compounds. Preliminary studies have shown that less than 1% of extractable organic Br compounds (EOBr) and total Br (TBr) in environmental samples could be identified. The proposed research will: 1) identify and quantify novel EOBrs in a range of marine and freshwater organisms; 2) use a mass balance (on Br) approach to determine what additional EOBrs might be present; An extraction and cleanup method for TBr, EOBr and five classes of identified EOBrs, based on molecular size and polarity has been developed and will be applied so that appropriate subsequent identification procedures can be applied and 3) use bioassays to determine the toxicity and potential beneficial effects of novel EOBrs will be subjected to a range of bioassays to determine: 1) their toxic mode of action and threshold for effects and 2) their potential as therapeutic agents. If compounds are determined to be too toxic, they will not be tested further for therapeutic properties.