Synthesis, phytotoxic evaluation and in silico studies for the development of novel natural products-inspired herbicides

Natural products are viable sources for the design of new chemical entities that may have their activities improved by fast/inexpensive synthetic modifications of their substituents. Herein we report the synthesis of six analogs of 2,4,5-trimethoxybenzaldehyde (1), a phenolic derivate isolated from Duguetia furfuracea, their corresponding phytotoxic activities and the predicted affinities concerning the inhibition of the auxin-binding protein (ABP-1). The synthesized compound 4b, methyl 2-(2,4,5-trimethoxyphenoxy)propanoate, showed the same growth-inhibition effect compared to the natural product 1 on the hypocotyl of the dicotyledon model, while 4c and 5a, (2-(2,4,5-trimethoxyphenoxy) acetic acid and 2-(2,4,5-trimethoxyphenoxy propanoic acid, respectively), demonstrated epinastic activities. The potential of interacting with the auxin-binding protein (ABP-1) was investigated by molecular docking and has shown that all the synthesized compounds were able to bind to the ABP-1 active site by similar patters of binding of the reference compound, 1-naphthalene acetic acid by hydrogen bond interactions and hydrophobic contributions. The compounds presented in this study could be highlighted as potential herbicide agents with anti-ABP-1, as well as 2,4,5-trimethoxybenzaldehyde as a good prototype to the development of new herbicides agents to the agrochemical industry.