title: Acute toxicity of chlorobenzenes in tetrahymena: estimated by microcalorimetry and mechanism.
abstract: The toxicity of chlorobenzenes to Tetrahymena growth metabolism was studied by microcalorimetry. The growth constant (k), peak time (T) and generation times (T(G)) were calculated. IC(50) of chlorobenzenes was obtained through the kinetic parameters. The results suggested that the order of toxicity was 1,2,4-trichlorobenzene>o-dichlorobenzene>p-dichlorobenzene>m-dichlorobenzene>chlorobenzene. ATR-FTIR spectra revealed that amide groups and PO(2)(-) of the phospholipid phospho-diester, both in the hydrophobic end exposed to the outer layer, were the easiest to be damaged. The relationship between IC(50) and chemicals structure parameters (E(LUMO), E(HOMO), logK(OW), ∑Q(R), ΔQ(πR) and ΔE), indicated that the more chlorine atoms were substituted, the greater the toxicity was. Chlorobenzenes have toxicity of non-polar narcosis. Their toxicity is proportional to their concentrations at the site of action, and caused by membrane perturbation.
authors.affiliation: Department of Chemistry, School of Science, Wuhan University of Technology, Wuhan, PR China.
authors.forename: Tian
authors.initials: T
authors.lastname: Zhang
authors.forename: Xi
authors.initials: X
authors.lastname: Li
authors.forename: Xinmin
authors.initials: X
authors.lastname: Min
authors.forename: Tingting
authors.initials: T
authors.lastname: Fang
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Zhang
authors.forename: Lu
authors.initials: L
authors.lastname: Yang
authors.forename: Peng
authors.initials: P
authors.lastname: Liu
mesh_terms: D020003:1-Octanol / Q000737:chemistry; D002151:Calorimetry / Q000379:methods; D002713:Chlorine / Q000737:chemistry; D002722:Chlorobenzenes / Q000737:chemistry / Q000633:toxicity*; D057927:Hydrophobic and Hydrophilic Interactions; D017550:Spectroscopy, Fourier Transform Infrared; D013768:Tetrahymena / Q000187:drug effects* / Q000254:growth & development; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*
chemical_list: D002722:Chlorobenzenes; D014874:Water Pollutants, Chemical; D014867:Water; D002713:Chlorine; D020003:1-Octanol