Chemical and ecological evaluation of rhodanine derivatives through aquatic bioindicators

Infectious diseases remain one of the main challenges in medicine, intensified by the constant adaptation of microorganisms, which develop resistance to pre-existing drugs. Thus, the search for new antimicrobial compounds has become increasingly necessary. However, the synthesis of these structures is associated with environmental impacts resulting from the improper disposal of toxic by-products. To minimize the risks of ecosystem degradation, predictive ecotoxicology emerges as an effective alternative for the prior assessment of effects such as bioconcentration, bioaccumulation, and biomagnification, based on parameters such as logKow, solubility, and concentration. Given this, this study aims to investigate, through QSAR and QSPR mathematical methods associated with statistical analysis, the potential toxicological effects of thirteen derivatives of rhodanine, a heterocyclic compound recognized for its pharmacological relevance due to its antiviral, antifungal, and, especially, antibacterial activities. In this study, the derivatives showed moderate and low acute and chronic toxicity in fish, Daphnia magna , and Green algae , as well as affinity with sediment and soil according to the logKow and solubility analysis, being mostly persistent in these media. Furthermore, based on the investigation of concentrations, a biomagnification relationship between biomarkers could be assessed, corroborating the previous result. It was found that halogenated substituents possibly favored increased toxicity by strengthening hydrophobicity, with RHD4 being the derivative with the highest toxic potential. In this sense, the purpose of this study is to promote the development of methods to reduce the risks of environmental impacts caused by the synthesis of antibacterial drugs, in accordance with the guidelines established by current environmental legislation.