New Antifungal and Antifeedant Metabolites from <i>Daldinia Eschscholtzii</i> Cocultured with <i>Colletotrichum Pseudomajus</i>

The synchronous co-culture of Daldinia eschscholtzii and Colletotrichum pseudomajus produced one new linear polyketide, eschscholin C (1), along with three known compounds (2-4). One new acorane sesquiterpene, coldaldrin A (5), and one new amide derivative, coldaldamide A (6) as the probe for polyketide intermediate capture, and three known compounds (7-9) were isolated from the sequential co-culture of D. eschscholtzii with C. pseudomajus. The structures and absolute configurations of 1, 5 and 6 were established by spectroscopic analysis including 1D, 2D NMR, the calculations of the NMR, and ECD data. Most compounds showed significant antifungal activities against the tea pathogens C. pseudomajus, and Fusarium asiaticum with MICs of 2-8 μg/mL. Compound 4 also showed antifeedant activity against silkworms with feeding deterrence indices of 79 % at the concentration of 50 μg/cm².