Biosciences, College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter, EX4 4QD UK.
Petroleum and Environmental Geochemistry Group, Biogeochemistry Research Centre, University of Plymouth, Drake Circus, Plymouth, PL4 8AA, UK.
Chemosphere. 2018 Aug;205:98-107. doi: 10.1016/j.chemosphere.2018.04.079. Epub 2018 Apr 14.
Petroleum acids, often called 'Naphthenic Acids' (NA), enter the environment in complex mixtures from numerous sources. These include from Produced and Process-Affected waters discharged from some oil industry activities, and from the environmental weathering of spilled crude oil hydrocarbons. Here, we test the hypothesis that individual NA within the complex mixtures can induce developmental abnormalities in fish, by screening a range of individual acids, with known chemical structures. Sixteen aromatic NA were tested using a Thamnocephalus platyrus (beavertail fairyshrimp) assay, to establish acute toxicity. Toxicities ranged from 568 to 8 μM, with the methylbiphenyl acid, 4-(p-tolyl)benzoic acid, most toxic. Next, five of the most toxic monoacids and for comparison, a diacid, were assayed using Danio rerio (zebrafish) embryos to test for lethality and developmental abnormalities. The toxicities were also predicted using Admet predictor™ software. Exposure to the five monoacids produced deformities in zebrafish embryos in a dose-dependent manner. Thus, exposure to 4-(p-tolyl)benzoic acid produced abnormalities in >90% of the embryos at concentrations of <1 μM; exposure to dehydroabietic acid caused pericardial edema and stunted growth in 100% of the embryos at 6 μM and exposure to pyrene-1-carboxylic acid caused 80% of embryos to be affected at 3 μM. The findings of this preliminary study therefore suggest that some aromatic acids are targets for more detailed mechanistic studies of mode of action. The results should help to focus on those NA which may be important for monitoring in oil industry wastewaters and polluted environmental samples.
石油酸，通常被称为“环烷酸”（NA），从许多来源以复杂混合物的形式进入环境。这些来源包括某些石油工业活动排放的采出物和处理过的水，以及溢油碳氢化合物的环境风化。在这里，我们通过筛选一系列具有已知化学结构的单个酸，来测试混合物中的单个 NA 是否会引起鱼类发育异常的假设。使用 Thamnocephalus platyrus（海狸尾虾虎鱼）测定法对 16 种芳香族 NA 进行了测试，以确定其急性毒性。毒性范围从 568 到 8 μM，其中甲基联苯酸、4-（对甲苯基）苯甲酸毒性最强。接下来，使用 Danio rerio（斑马鱼）胚胎对五种最毒的单酸和两种二酸进行了测试，以测试其致死性和发育异常。使用 Admet predictor™软件预测了毒性。五种单酸以剂量依赖的方式在斑马鱼胚胎中产生畸形。因此，在浓度低于 1 μM 的情况下，4-（对甲苯基）苯甲酸暴露导致超过 90%的胚胎出现异常；在 6 μM 的浓度下，脱氢枞酸导致 100%的胚胎出现心包水肿和生长迟缓；在 3 μM 的浓度下，芘-1-羧酸导致 80%的胚胎受到影响。因此，这项初步研究的结果表明，一些芳香族酸是作用模式的更详细机制研究的目标。这些结果应该有助于将重点放在那些可能对监测石油工业废水中和污染环境样本中重要的 NA 上。
