Finch Bryson E, Marzooghi Solmaz, Di Toro Dominic M, Stubblefield William A
Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon, USA.
Department of Civil and Environmental Engineering, University of Delaware, Newark, Delaware, USA.
Environ Toxicol Chem. 2017 Aug;36(8):2043-2049. doi: 10.1002/etc.3733. Epub 2017 Feb 13.
Crude oils are composed of an assortment of hydrocarbons, some of which are polycyclic aromatic hydrocarbons (PAHs). Polycyclic aromatic hydrocarbons are of particular interest due to their narcotic and potential phototoxic effects. Several studies have examined the phototoxicity of individual PAHs and fresh and weathered crude oils, and several models have been developed to predict PAH toxicity. Fingerprint analyses of oils have shown that PAHs in crude oils are predominantly alkylated. However, current models for estimating PAH phototoxicity assume toxic equivalence between unsubstituted (i.e., parent) and alkyl-substituted compounds. This approach may be incorrect if substantial differences in toxic potency exist between unsubstituted and substituted PAHs. The objective of the present study was to examine the narcotic and photo-enhanced toxicity of commercially available unsubstituted and alkylated PAHs to mysid shrimp (Americamysis bahia). Data were used to validate predictive models of phototoxicity based on the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gap approach and to develop relative effect potencies. Results demonstrated that photo-enhanced toxicity increased with increasing methylation and that phototoxic PAH potencies vary significantly among unsubstituted compounds. Overall, predictive models based on the HOMO-LUMO gap were relatively accurate in predicting phototoxicity for unsubstituted PAHs but are limited to qualitative assessments. Environ Toxicol Chem 2017;36:2043-2049. © 2017 SETAC.
原油由各种碳氢化合物组成，其中一些是多环芳烃（PAHs）。多环芳烃因其麻醉和潜在的光毒性作用而备受关注。多项研究已考察了单个多环芳烃以及新鲜和风化原油的光毒性，并且已开发出多种模型来预测多环芳烃的毒性。对油类的指纹分析表明，原油中的多环芳烃主要是烷基化的。然而，当前用于估算多环芳烃光毒性的模型假定未取代（即母体）化合物和烷基取代化合物之间具有毒性等效性。如果未取代和取代的多环芳烃在毒性效力上存在实质性差异，那么这种方法可能是不正确的。本研究的目的是考察市售未取代和烷基化多环芳烃对糠虾（美洲糠虾）的麻醉和光增强毒性。数据用于验证基于最高占据分子轨道 - 最低未占据分子轨道（HOMO - LUMO）间隙方法的光毒性预测模型，并确定相对效应强度。结果表明，光增强毒性随着甲基化程度的增加而增加，并且光毒性多环芳烃的效力在未取代化合物之间存在显著差异。总体而言，基于HOMO - LUMO间隙的预测模型在预测未取代多环芳烃的光毒性方面相对准确，但仅限于定性评估。《环境毒理学与化学》2017年；36:2043 - 2049。© 2017 SETAC。
