Antifungal agents. Part 5: Synthesis and antifungal activities of aminoguanidine derivatives of N-arylsulfonyl-3-acylindoles

In order to discover more promising antifungal agents, a series of aminoguanidine derivatives of N-arylsulfonyl-3-acylindoles (5a–r) were prepared and evaluated in vitro for their antifungal activities against seven phytopathogenic fungi. Especially compounds 5n and 5o exhibited more potent antifungal activities than or comparable to hymexazol, a commercially available agricultural fungicide at the concentration of 100 μg/mL. Preliminary structure–activity relationships study demonstrated that introduction of electron-donating substituents R1 and R2, and the proper length of substituent R3 were usually very important for their antifungal activities.

Graphical abstractEighteen Aminoguanidine derivatives of N-arylsulfonyl-3-acylindoles were prepared and bio-evaluated in vitro as antifungal agents against seven phytopathogenic fungi. Preliminary structure–activity relationships analysis demonstrated that introduction of electron-donating substituents R1 and R2, and the proper length of substituent R3 were very important for their antifungal activities.Figure optionsDownload full-size imageDownload as PowerPoint slide