Design, Synthesis, and Antifungal Activity of 4-Amino Coumarin Based Derivatives

A series of 30 succinate dehydrogenase inhibitors (SDHIs) of 4-amino coumarin-based derivatives were designed and synthesized. According to the analysis of fungicidal activity in vitro, most of the compounds expressed broad-spectrum antifungal activity against four plant pathogenic fungi (Alternaria alternata, Alternaria solani, Fusarium oxysporum,andBotrytis cinerea) using the mycelium growth inhibition method. The results showed that compounds3nwith the group of 2-ene-3-methyl-butyl and4ewith the group of 2-bromo-1-oxo-hexyl displayed excellent activity againstAlternaria alternataandAlternaria solani, with EC50values of 92~145 μg/mL. Molecular docking showed that the inhibitor3nwas completely locked into the cavity of SDH, forming a conventional hydrogen bond interacting with the amino acid residue TYR58. The present work indicates that these derivatives would serve as novel potential fungicides targeting SDH.Keywords:succinate dehydrogenase;inhibitor;4-amino coumarin;fungicide;antifungal activity;molecular docking