title: Quantitative structure-activity relationships for chronic toxicity of alkyl-chrysenes and alkyl-benz[a]anthracenes to Japanese medaka embryos (Oryzias latipes).
abstract: Alkylated polycyclic aromatic hydrocarbons (alkyl-PAHs) are a class of compounds found at significant concentrations in crude oils, and likely the main constituents responsible for the chronic toxicity of oil to fish. Alkyl substituents at different locations on the aromatic rings change the size and shape of PAH molecules, which results in different interactions with tissue receptors and different severities of toxicity. The present study is the first to report the toxicity of several alkylated derivatives of chrysene and benz[a]anthracene to the embryos of Japanese medaka (Oryzias latipes) using the partition controlled delivery (PCD) method of exposure. The PCD method maintained the desired exposure concentrations by equilibrium partitioning of hydrophobic test compounds from polydimethylsiloxane (PDMS) films. Test concentrations declined by only 13% over a period of 17 days. Based on the prevalence of signs of blue sac disease (BSD), as expressed by median effective concentrations (EC50s), benz[a]anthracene (B[a]A) was more toxic than chrysene. Alkylation generally increased toxicity, except at position 2 of B[a]A. Alkyl-PAHs substituted in the middle region had a lower EC50 than those substituted at the distal region. Except for B[a]A and 7-methylbenz[a]anthracene (7-MB), estimated EC50 values were higher than their solubility limits, which resulted in limited toxicity within the range of test concentrations. The regression between log EC50s and logKow values provided a rough estimation of structure-activity relationships for alkyl-PAHs, but Kow alone did not provide a complete explanation of the chronic toxicity of alkyl PAHs.
authors.affiliation: Department of Biology, Queen's University, Kingston, Ontario K7L3N6, Canada.
authors.forename: Hongkang
authors.initials: H
authors.lastname: Lin
authors.affiliation: School of Environmental Studies, Queen's University, Kingston, Ontario K7L3N6, Canada.
authors.forename: Garrett D
authors.initials: GD
authors.lastname: Morandi
authors.affiliation: School of Environmental Studies, Queen's University, Kingston, Ontario K7L3N6, Canada; Department of Chemistry, Queen's University, Kingston, Ontario K7L3N6, Canada.
authors.forename: R Stephen
authors.initials: RS
authors.lastname: Brown
authors.affiliation: Department of Chemistry, Queen's University, Kingston, Ontario K7L3N6, Canada.
authors.forename: Victor
authors.initials: V
authors.lastname: Snieckus
authors.affiliation: Department of Chemistry, Queen's University, Kingston, Ontario K7L3N6, Canada.
authors.forename: Toni
authors.initials: T
authors.lastname: Rantanen
authors.affiliation: Department of Mathematics and Natural Sciences, University of Stavanger, 4036 Stavanger, Norway.
authors.forename: Kåre B
authors.initials: KB
authors.lastname: Jørgensen
authors.affiliation: Department of Biology, Queen's University, Kingston, Ontario K7L3N6, Canada; School of Environmental Studies, Queen's University, Kingston, Ontario K7L3N6, Canada. Electronic address: peter.hodson@queensu.ca.
authors.forename: Peter V
authors.initials: PV
authors.lastname: Hodson
mesh_terms: D000478:Alkylation; D000818:Animals; D000873:Anthracenes / Q000737:chemistry* / Q000633:toxicity*; D002911:Chrysenes / Q000737:chemistry* / Q000633:toxicity*; D004625:Embryo, Nonmammalian / Q000187:drug effects; D009990:Oryzias / Q000502:physiology*; D010578:Petroleum; D011084:Polycyclic Aromatic Hydrocarbons / Q000633:toxicity; D021281:Quantitative Structure-Activity Relationship; D013329:Structure-Activity Relationship; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity
chemical_list: D000873:Anthracenes; D002911:Chrysenes; D010578:Petroleum; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical; C031180:chrysene; C034020:anthracene
keywords: Alkylated polycyclic aromatic hydrocarbons; Chronic embryo toxicity; Medaka; Partition controlled delivery; Structure–activity relationships