Natural Products‐Based Fungicides: Synthesis and Antifungal Activity against Plant Pathogens of 2 H ‐Chromene Derivatives

Aiming to search for novel potential antifungal agents, forty 2 H ‐chromene analogs were designed, synthesized and their antifungal activity against some typical plant pathogenic fungi were firstly evaluated. The in vitro antifungal bioassays showed that some of the target compounds exhibited comparable or better inhibition activities than the commercial agricultural fungicide hymexazol. Especially compound 1m displayed more promising fungicidal effect against Alternaria alternate (EC 50 =9.9 μg/mL) and Botrytis cinerea (EC 50 =9.4 μg/mL), which was significantly superior to hymexazol. Moreover, in vivo protective effects results also indicated that compound 1m had an excellent potential for further development as a new botanical pesticide.