Acute Toxicities and QSAR of Substituted Phenols to Photobacterium Phosphoreum at Different pH

The acute toxicities (the concentration value causing a 50% inhibition of bioluminescence after 15 minutes, abbreviated 15 min-EC
₅₀
) of 12 substituted phenols to photobacterium phosphoreum were measured at different pH (5.0, 7.0, 9.0). The quantitative structure-activity relationship was studied by applying two physicochemical parameters logP and E
_HOMO
. And the toxicity mechanism was preliminarily discussed. The results showed that the toxicities of substituted phenols decreased with pH, but the effect is not very significant. The toxicities of substituted phenols vary with the kind, the number and the position of substituents at the same pH. The inosculation of the fitted toxicities and the observed toxicities is considerably satisfying through QSAR research.