Use of Quantitative Structure-activity Relationship to Model the Photoinduced Toxicity of Anthracene and Oxygenated Anthracenes

Polycyclic aromatic hydrocarbons (PAHs) are known to exhibit photoinduced toxicity to organisms, especially in the presence of ultraviolet irradiation. Oxidation is the most common photochemical reaction of anthracene (ANT) and ANT derivatives. Quinones, hydroxy-quinones, diols, and aldehydes are the resultant products. Different ANT photoproducts have different impact on biological organisms. The structure of these molecules contains information concerning their toxicity. From two main bioenergetic pathways in aerobic organisms (respiration and photosynthesis), we have previously reported the inhibition of photosynthesis by ANT derivatives. We showed that inhibition of photosynthesis is a reliable assay of xenobiotic stress. To study the correlation between chemical structures and toxicity, precise structure of anthracene (ANT), anthraquinone (ATQ) and eleven hydroxyanthraquinones (hATQs) were constructed. A numerical comparison of molecular shape codes was used for shape comparison and similarity analysis. The data sets for growth inhibition showed good correlations to the shape similarity. Both the one ring and whole molecule similarities of ANT, ATQ and hATQs showed a good correlation with the empirical whole organism toxicity data. The IC50 values for FV/FM and FQ/FM were plotted against hyperbolic dependencies of one-ring and whole molecule similarity to determine their predictive capacity. The two data sets for FQ/ FM and FV/FM have reasonable regression coefficients, and both were found to be excellent bioindicators of effects. In this study correlation between the shape of chemicals and the biological activity provides necessary information related to toxicity of hazard chemicals based on chemical and biological properties of their reactions.