Design, Synthesis and Antifungal Activity of Coumarin Ring-Opening Derivatives

Based on our initial design, we synthesized two series of coumarin ring-opening derivatives by the reactions of hydrolysis and methylation. Results of antifungal screening in vitro showed that the target compounds exhibited potent activity against the six common pathogenic fungi. Compounds 6b, 6e, 6g, 6i, 7b and 7c were identified as the most active ones, and the EC50 values of these active compounds were further tested. Compared to the commonly used fungicide Azoxystrobin (0.0884 mu M), compounds 6b (0.0544 mu M) and 6e (0.0823 mu M) displayed improved activity against Botrytis cinerea.