Antifungal Halogenated Cyclopentenones from the Endophytic Fungus Saccharicola bicolor of Bergenia purpurascens by One Strain-Many Compounds Strategy.
الكلمات الدالة
نبذة مختصرة
Phytopathogenic fungi have been acknowledged as being an enormous threat in the agricultural system. In our search of new antifungal natural products, nine new halogenated cyclopentenones, bicolorins A-I (1-3, and 5-10), along with three known cyclopentenones (4, 11 and 12), were isolated from the endophytic fungus Saccharicola bicolor of Bergenia purpurascens by one strain-many compounds strategy. Their structures and absolute configurations were elucidated based on extensive spectroscopic analysis, X-ray crystallographic analysis, and TD-DFT-ECD calculations. Compounds 1-12 showed antifungal activities against five phytopathogenic fungi (Uromyces viciae-fabae, Pythium dissimile, Gibberella zeae, Aspergillus niger and Sclerotinia sclerotiorum). Especially, bicolorins B and D (2 and 5) exhibited strong antifungal activities against P. dissimile with the MIC values of 6.2 and 8.5 μg/mL, respectively, compared with the positive control cycloheximide (MIC of 8.6 μg/mL). Additionally, bicolorin D was proved to be potently antifungal against S. sclerotiorum in vitro and in vivo. This work provides an effective strategy for searching antifungal candidate agents.