Antifouling and Fungicidal Resorcylic Acid Lactones from the Sea Anemone-Derived Fungus Cochliobolus lunatus

作者:Liu, Qing-Ai; Shao, Chang-Lun; Gu, Yu-Cheng; Blum, Mathias; Gan, Li-She; Wang, Kai-Ling; Chen, Min; Wang, Chang-Yun*
来源:Journal of Agricultural and Food Chemistry, 2014, 62(14): 3183-3191.
DOI:10.1021/jf500248z

摘要

Three new 14-membered resorcylic acid lactones, cochliomycins D-F, 1-3, and eight known analogues, 4-11, were isolated from the sea anemone-derived fungus Cochliobolus lunatus. Compounds 1-4 are diastereomers differing from each other by the absolute configurations of the 4',5'-diol chiral centers. The absolute configurations of 1-4 were established by the CD exciton chirality method and TDDFT ECD calculations. In antifouling assays, 1, 3-6, and 6a exhibited potent antifouling activities against the larval settlement of the barnacle Balanus amphitrite at nontoxic concentrations, with EC50 values ranging from 1.82 to 22.5 mu g/mL. Noticeably, fungicide whole-plant assays indicated that 6 showed excellent activity on the Plasmopara viticola preventative test at 6 ppm and concentration-dependent activity on the Phytophthora infestans preventative application at 200, 60, and 20 ppm. Preliminary structure-activity relationships are also discussed.