Antifungal agents. Part 3: synthesis and antifungal activities of 3-acylindole analogs against phytopathogenic fungi in vitro.

To find more potent antifungal compounds, twenty 3-acylindole analogs were synthesized and bio-evaluated for their antifungal activities against seven phytopathogenic fungi. Structure-activity relationships investigations revealed that 4- or 6-methyl and 3-acetyl or propionyl groups were the important structural properties of 3-acylindoles for the activities. Especially 4-methyl-3-propionylindole, 12, displayed the more potent activities than hymexazol, a commercially available agricultural fungicide, and might be considered as a new promising lead candidate for further design and synthesis of agricultural fungicides.