ORIGINAL ABSTRACT

Eight eugenol-derived 1,2,3-triazole derivatives (2a-2h) were evaluated for their phytotoxic and cytogenotoxic activities. Bioassays were performed using Lactuca sativa to assess macroscopic parameters, including germination percentage, germination speed index, and root growth (RG), as well as microscopic parameters, such as the mitotic index (MI) and chromosomal alteration (CA) and nuclear alteration (NA). Compounds 2b and 2e, bearing ortho-bromine and meta-chlorine substituents, respectively, exhibited the highest phytotoxic activity, with effects comparable to glyphosate. In contrast, 2c, 2d, 2f, 2g, and 2h, which contain other halogens and different aromatic patterns, stimulated RG. Cytogenetic analysis revealed that 2b and 2e significantly reduced the MI and increased NA and CA, indicating cytotoxic and genotoxic potential. Theoretical calculations of physicochemical properties showed that 2b, 2e, and 2g are hydrophilic. In contrast, the others are lipophilic, a feature that may influence their interaction with plant tissues and help explain the observed differences. Compared with glyphosate, the compounds 2b and 2e exhibited a variety of intermolecular interactions due to their hydrophilic behavior, resulting in lower docking energy and surpassing the quality and quantity of interactions observed with glyphosate itself. These findings highlight 2b and 2e as promising candidates for the development of herbicides with alternative modes of action.