Acute oral toxicity and liver oxidant/antioxidant stress of halogenated benzene, phenol, and diphenyl ether in mice: a c
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RESEARCH ARTICLE
Acute oral toxicity and liver oxidant/antioxidant stress of halogenated benzene, phenol, and diphenyl ether in mice: a comparative and mechanism exploration Jiaqi Shi & Mingbao Feng & Xuesheng Zhang & Zhongbo Wei & Zunyao Wang
Received: 3 December 2012 / Accepted: 11 March 2013 # Springer-Verlag Berlin Heidelberg 2013
Abstract The lethal doses (LD50s) of fluorinated, chlorinated, brominated, and iodinated benzene, phenol, and diphenyl ether in mice were ascertained respectively under the consistent condition. The acute toxicity of four benzenes orders in fluorobenzene (FB) < iodobenzene < chlorobenzene≈bromobenzene, that of four phenols orders in 4-iodophenol≈4-bromophenol < 4-chlorophenol (4-MCP) < 4-fluorophenol (4-MFP), and that of four diphenyl ethers orders in 4,4′-iododiphenyl ether iodo while desensitization sequence was fluoro>chloro>bromo>iodo (Pero et al. 1977). Besides, the overall order of nucleophilic reactivity against some fungus target was fluoro >iodo>bromo>chloro. This was consistent with the order of leaving groups (Gershon et al. 1995). The octanol–water partition coefficient (logKow) on halogenated dibenzofurans with the same substituting number and position ranks in the order of brominated>chlorinated>fluoric (Shi et al. 2011). Especially, fluorinated organics sometimes show different properties from chlorinated, brominated, and iodinated ones. For instance, the first-order degradation rate constant of halogenobenzene at infinite dilution, was not significantly different for CB, BB, and IB but was significantly higher for FB (Drijvers et al. 2000) and the relative hydrogen-bond acceptor strength of
Environ Sci Pollut Res
the halogens orders in: FB>CB≈BB≈IB (Ouvrard et al. 1999). Moreover, fluorodinitrobenzene was expected to be more susceptible to nucleophilic attack than its analogs because of the greater polarization of the C–F bond compared with bonds involving C1, Br, or I. In the corresponding series of benzenes, p- and o-phenols and p- and m-benzoic acids, the values of the logKow for the chloro, bromo, and iodo derivatives were larger, on the average, than that for the fluoro derivative by factors of 3.5, 5.6, and 10, respectively (Krupka and Deves 1980). In many chemical reactions, fluorodinitrobenzene was more reactive than its analogs by much larger factors (Whalley 1950; Chapman and Parker 1951; Bunnett 1957; Bunnett and Merritt 1957; Bunnett et al. 1957). For instance, with aniline in ethanol at 50 °C, it reacts 60 times faster than chlorodinitrobenzene, 40 times faster than bromodinitrobenzene, and 130 times faster than iododinitrobenzene (Krupka and Deves 1980). The trend on logKow for PFDFs did not monotonously increase with the number of substituents as the PCDFs and PBDFs did but instead appeared to be a three-level sawtooth shape, which was intriguing. On each level, logKow values increased slightly with the number of fluorine atoms (Shi et al. 2011). As is known, halogenated aromatic chemicals are common toxicants and have caused wide public concern (P
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