The Acute Toxicity of α-Branched Phenylsulfonyl Acetates in Photobacterium phosphoreum Test

The acute toxicity (15-min EC50) of 20 α-substituted phenylsulfonyl acetates was measured using the Microtox test with Photobacterium phosphoreum. On the basis of TLSER, quantitative structure–activity relationships (QSARs) were calculated for the inhibition of bioluminescence. With the parameters molecular volume (Vmc), dipolarity/polarizability (π*), and the covalent contribution to Lewis basicity (var epsilonb), a squared correlation coefficient (r2adj) of 0.868 and standard error of 0.094 for log EC50 were obtained. By introducing a structural indicator variable (I), the regressive quality was improved (correlation coefficient of 0.948 and standard error of 0.059); the descriptors Vmc, π*, and the electrostatic basicity contribution (q−) were significant. –NO2– and –SO2– groups are active centers of these compounds. The strong hydrogen bonding effects between the compound active centers and FMNH2 play an important role in the greater toxicity of these chemicals.