Synthesis and Anti-Oomycete Activity of Sulfonate Derivatives of Fenjuntong

In order to discover highly active fungicides, sixteen novel sulfonate derivatives of Fenjuntong were synthesized by structural modification of 2′-hydroxybutyrophenone, and their anti-oomycete activity against Phytophthora capsici Leonian was determined in this study. Among all tested compounds, compound 3b displayed more significant anti-oomycete activity than the precursor Fenjuntong against P. capsici , and the EC 50 values of 3b and Fenjuntong were 84.50 and 517.25 mg/L, respectively. By comparing the anti-oomycete activity of compounds 3a – p , I-a – p , and II-a – p , the following conclusions were drawn: (1) Hydroxy group is well tolerated, and sulfonylation of hydroxy group enhances its anti-oomycete activity. (2) The proper length of the ketone carbonyl chain is very important for their anti-oomycete activity. (3) The presence of a site methoxy group in the structural skeleton is closely related to the anti-oomycete activity. These important results will pave the way for further modification of Fenjuntong to develop potential new fungicides. Graphical