title: Zebrafish embryo toxicity of anaerobic biotransformation products from the insensitive munitions compound 2,4-dinitroanisole.
abstract: 2,4-Dinitroanisole (DNAN) is an emerging insensitive munitions compound that readily undergoes anaerobic nitro-group reduction to 2-methoxy-5-nitroaniline (MENA) and 2,4-diaminoanisole (DAAN), followed by formation of unique azo dimers. Currently there is little knowledge on the ecotoxicity of DNAN (bio)transformation products. In the present study, mortality, development, and behavioral effects of DNAN (bio)transformation products were assessed using zebrafish (Danio rerio) embryos. The authors tested individual products, MENA and DAAN, as well as dimer and trimer surrogates. As pure compounds, 3-nitro-4-methoxyaniline and 2,2'-dimethoxy-4,4'-azodianiline caused statistically significant effects, with lowest-observable-adverse effect levels (LOAEL) at 6.4 μM on 1 or 2 developmental endpoints, respectively. The latter had 6 additional statistically significant developmental endpoints with LOAELs of 64 μM. Based on light-to-dark swimming behavioral tests, DAAN (640 μM) caused reduction in swimming, suggestive of neurotoxicity. No statistically significant mortality occurred (≤64 μM) for any of the individual compounds. However, metabolite mixtures formed during different stages of MENA (bio)transformation in soil were characterized using high-resolution mass spectrometry in parallel with zebrafish embryo toxicity assays, which demonstrated statistically significant mortality during the onset of azo-dimer formation. Overall the results indicate that several DNAN (bio)transformation products cause different types of toxicity to zebrafish embryos. Environ Toxicol Chem 2016;35:2774-2781. © 2016 SETAC.
authors.affiliation: Department of Chemical and Environmental Engineering, University of Arizona, Tucson, Arizona, USA.
authors.forename: Christopher I
authors.initials: CI
authors.lastname: Olivares
authors.affiliation: Department of Chemical and Environmental Engineering, University of Arizona, Tucson, Arizona, USA.
authors.forename: Reyes
authors.initials: R
authors.lastname: Sierra-Alvarez
authors.affiliation: Department of Soil, Water and Environmental Science, University of Arizona, Tucson, Arizona, USA.|Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona, USA.
authors.forename: Leif
authors.initials: L
authors.lastname: Abrell
authors.affiliation: Department of Soil, Water and Environmental Science, University of Arizona, Tucson, Arizona, USA.
authors.forename: Jon
authors.initials: J
authors.lastname: Chorover
authors.affiliation: Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory and the Environmental Health Sciences Center at Oregon State University, Corvallis, Oregon, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Simonich
authors.affiliation: Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory and the Environmental Health Sciences Center at Oregon State University, Corvallis, Oregon, USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Tanguay
authors.affiliation: Department of Chemical and Environmental Engineering, University of Arizona, Tucson, Arizona, USA. jimfield@email.arizona.edu.
authors.forename: Jim A
authors.initials: JA
authors.lastname: Field
mesh_terms: D000693:Anaerobiosis; D000814:Aniline Compounds / Q000378:metabolism / Q000633:toxicity*; D000818:Animals; D000840:Anisoles / Q000378:metabolism / Q000633:toxicity*; D001522:Behavior, Animal / Q000187:drug effects; D001711:Biotransformation; D004625:Embryo, Nonmammalian / Q000187:drug effects* / Q000378:metabolism; D047108:Embryonic Development / Q000187:drug effects*; D053834:Explosive Agents / Q000378:metabolism / Q000633:toxicity*; D013058:Mass Spectrometry; D010655:Phenylenediamines / Q000378:metabolism / Q000633:toxicity*; D012987:Soil; D015027:Zebrafish / Q000196:embryology* / Q000378:metabolism
chemical_list: D000814:Aniline Compounds; D000840:Anisoles; D053834:Explosive Agents; D010655:Phenylenediamines; D012987:Soil; C539360:2,4-dinitroanisole; C007294:4-methoxy-3-phenylenediamine; C034087:5-nitro-2-methoxyaniline
keywords: 2,4-Dinitroanisole; Azo dimer; Biotransformation; Developmental toxicity; Ecotoxicology; Zebrafish