Toxicity of dioxins: role of an absolute hardness-absolute electronegativity diagram (eta-chi diagram) as a new measure in risk assessment.
The differences in biological activities among polychlorinated dibenzo-p-dioxins (dioxins) are strongly dependent on the substitution pattern of chlorine at various positions on the parent dibenzo-p-dioxin molecule. The absolute hardness, eta, of dioxins shows a good correlation with the potency of biological activity and the chlorine substitution pattern. The result means that the soft dioxins have a small HOMO-LUMO gap, and are more toxic than the hard dioxins. Therefore, the values of absolute hardness, eta, of dioxins can be used to predict their toxic potency (dioxin hardness). Moreover, we show that the absolute hardness-absolute electronegativity (eta-chi) diagrams, as an activity coordinate, play an important role as a new measure in the assessment of the toxicity and potency of the biological activity of dioxins.
Showa College of Pharmaceutical Science, Tokyo, Japan.
S
S
Kobayashi
K
K
Sameshima
Y
Y
Ishii
A
A
Tanaka
D000818:Animals; D004147:Dioxins / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D004563:Electrochemistry; D006168:Guinea Pigs; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry / Q000633:toxicity*; D007928:Lethal Dose 50; D011485:Protein Binding; D018336:Receptors, Aryl Hydrocarbon / Q000378:metabolism; D013329:Structure-Activity Relationship; D014867:Water / Q000737:chemistry
D004147:Dioxins; D006843:Hydrocarbons, Chlorinated; D018336:Receptors, Aryl Hydrocarbon; D014867:Water