Study of the Interference in Target Seed Germination Caused by Dienamides and Epoxy Derivatives, in the Search for New Herbicides

Abstract

The indiscriminate use of herbicides makes weeds resistant, increasing the demand for more efficient herbicides. Novel potential herbicides were prepared from sorbic acid, being 8 dienamides and 6 epoxides. Subsequently, phytotoxic activities of sorbic acid and 14 synthesized compounds were evaluated against sorghum, onion, cucumber, lettuce, and beggartick seeds. Furthermore, the protein target of the most active substance in plants was identified in silico. Among the tested compounds, (2E,4E)-N-(p-fluorophenyl)hexa-2,4-dienamide (2c), (2E,4E)-N-(o-naphthyl) hexa-2,4-dienamide (2d), (E)-N-methylphenyl-3-((2R,3R)-3-methyloxiran-2-yl)acrylamide (3b), (E)-N-bromophenyl-3-((2R,3R)-3-methyloxiran-2-yl)acrylamide (3e), and (E)-N-methoxyphenyl-3-((2R,3R)-3-methyloxiran-2-yl)acrylamide (3f) showed pronounced inhibitory activities, both of shoots and roots, making them candidates for promising herbicides. All compounds altered seed development, and compounds 2c, 2d, 3b, 3e, and 3f presented equal or superior results to the commercial control herbicide S-metolachlor. Docking studies suggest that enzyme mitogen-activated protein kinase can be the target of those compounds.