Surface electrostatic potentials of polychlorinated dibenzofurans and their applications in quantitative structure-toxicity relationships

Polychlorinated dibenzofurans (PCDFs) represent an important kind of serious pollutant. They are highly toxic and persistent in environment. In this paper, geometrical optimizations and subsequent calculations of electrostatic potentials (ESPs) on molecular surface have been performed for all 135 PCDF congeners at the HF/6-31 G* level. The effects of substitution value and variation of substitution position upon the surface ESPs have been discussed. A series of statistic-based structural descriptors derived from the surface ESPs have been calculated. For some PCDF congeners, linear relationships between aryl hydrocarbon receptor (AhR) biding affinity and aryl hydrocarbon hydroxylase (AHH) induction potency as well as theoretical descriptors have been established by multiple linear regression method. It appears that the quantities derived from the surface ESPs, V-s,V-min, (V) over bar (s), <(V-s(+))over bar>, sigma(2)(+) and N-vmin together with the molecular surface area and the energy gap between HOMO and LUMO can be well used to express the quantitative structure-toxicity relationships of PCDFs.