PPO-Inhibiting Herbicides and Structurally Relevant Schiff Bases: Evaluation of Inhibitory Activities against Human Protoporphyrinogen Oxidase

The study of human protoporphyrinogen oxidase (hPPO) inhibition can contribute significantly to a better understanding some pathogeneses (e.g., porphyria, herbicide exposure) and the development anticancer agents. Therefore, we prepared new potential inhibitors with Schiff base structural motifs (2-hydroxybenzaldehyde-based bases 9–13 chromanone derivatives 17–19) as structurally relevant PPO herbicides. inhibitory activities (represented by half maximal concentration (IC50) values) enzymatic interactions hPPO melting temperatures) these synthetic compounds commercial herbicides used against were studied protoporphyrin IX fluorescence assay. In case herbicides, significant changes in temperature observed for oxyfluorten, oxadiazon, lactofen, butafenacil, saflufenacil, oxadiargyl, chlornitrofen, especially fomesafen. Nevertheless, did not display activity or temperature. However, designed model based on determined IC50 values docking (by using AutoDock) found important parts motif inhibition. This could be predict herbicidal toxicity improve design inhibitors.