Bioactivity and molecular properties of Phenoxyacetic Acids Derived from Eugenol and Guaiacol compared to the herbicide 2,4-D

Abstract

Herbicides are agrochemicals applied in the control of weeds. With the frequent and repetitive use of these substances, serious problems have been reported.Compounds of natural origin and their derivatives are attractive options to obtain new compounds with herbicidal properties. By aiming to develop compounds with potentiated herbicidal activity, phenoxyacetic acids were synthesized from eugenol and guaiacol. The synthesized compounds were characterized and the herbicidal potential of phenoxyacetic acids and precursors was evaluated through bioassays regarding the germination and initial development of Lactuca sativa and Sorghum bicolor seedlings, with the induction of DNA damage. The induction of changes in the mitotic cycle of meristematic cells of roots of L. sativa was also analyzed. At the concentration of 3 mmol L -1 , phenols and their respective phenoxyacetic acids presented phytotoxic and cytotoxic activities in L. sativa and S. bicolor. Eugenol and guaiacol also presented genotoxic action in L. sativa. The toxic effect of eugenoxyacetic acid was more pronounced in L. sativa than in S. bicolor, similar to the commercial 2,4-D herbicide. Molecular properties of the phenols and their derivatives phenoxyacetic acids were compared with the ones obtained for the herbicide 2,4-D, where it was found a correlation between their molecular properties and bioactivity.

Phytocytogenotoxicity of Esters obtained from Phenols and Phenoxyacetic Acid using the Steglich reaction

“…This relationship was observed in this study, as the esters 3, 4, and 5, derived from eugenol, carvacrol, and guaiacol, respectively, showed an increase in both the MI and the CA rate. The increase in the MI was also observed in L. sativa treated with eugenoxyacetic acid 30 .…”

“…Cell death may explain the reduction in growth of roots and aerial part of L. sativa and S. bicolor seedlings exposed to esters 1, 3, and 5 58 . Alves et al 30 found a 5-fold increase in the rate of adherent chromosomes in cells treated with eugenol and eugenoxyacetic acid.…”

“…Kasugai et al 53 observed the breakdown of the cell wall of bacteria treated with guaiacol. Meanwhile, Alves et al 30 found the death of meristematic cells in L. sativa roots exposed to guaiacol. The authors suggested that the possible action of guaiacol on cell walls may have led to the loss of essential molecules, compromising nutrient transport and cellular respiration in the organism.…”

“…δ C (100 MHz, [M] +. , 57); 250 (42); 157 (100); 144 (31); 129 (30); 127 (33); 115 (40); 107 (99); 79 (28); 77 (63); 51 (10); 39 (5). Biological Tests.…”

“…There is a report of studies exploring modi cations of eugenol for use as a precursor in obtaining other molecules with potential phytotoxic and cytotoxic activities 30 . For example, it can be used in the synthesis of coumarins from this phenol for the production of commercial herbicides 31 .…”