Study on acute toxicity and structure–activity relationship of Daphnia magna exposed to naphthoquinones

The acute toxicities of the six naphthoquinone compounds on Daphnia magna (D. magna) at 48 h were classified as harmful, toxic, and very toxic. The results indicated that log P played an important part in the toxicity of compounds to organism. And 1-carbonyl or the other hydrophobic substituents of the naphthoquinone compounds are likely to mediate the binding of the compound to the target via hydrogen bonding and hydrophobic interactions. Our results provided a foundation for further investigation using 3D-QSAR and HQSAR to evaluate the aquatic ecological risk and the mechanism of toxicity of naphthoquinones.

► The first study to research the toxicity mechanics of naphthoquinones on Daphnia magna. ► The acute toxicities on Daphnia magna were classified as harmful, toxic, and very toxic. ► log P played an important part in the toxicity of compounds to organism. ► Hydrophobic substituents may bind the compound to the target.