18-Residue Peptaibiotics from the <i>Suaeda glauca</i> -Derived Fungus <i>Acremonium persicinum</i> and Their Antifungal Potential against <i>Botrytis cinerea</i>

Fungal natural products have shown potential to control the resistance of <i>Botrytis cinerea</i> to synthetic fungicides. Bioassay-guided isolation from the <i>Suaeda glauca</i>-derived fungus <i>Acremonium persicinum</i> had obtained four novel 18-residue peptaibiotics, persicins A-D (<b>1</b>-<b>4</b>), showing antifungal potential against fungicide-resistant <i>B. cinerea</i> CJ-8. Their structures were elucidated through spectroscopic analyses and the modified Marfey's method. The representative persicin A (<b>1</b>) inhibited spore germination and prevented gray mold on table grapes. Studies on its antifungal mechanisms against <i>B. cinerea</i> CJ-8 revealed that persicin A could disrupt membrane integrity and fluidity, enhance membrane permeability, and induce oxidative stress. Persicin A also impaired intracellular Ca²⁺ homeostasis and then induced a decrease of the mitochondrial membrane potential (MMP). Moreover, persicin A inhibited mitochondrial respiratory chain complexes I and III, which thus reduced ATP production. In summary, this study first revealed antifungal potential of 18-residue peptaibiotics of the persicin series, which might be developed as biofungicides to control <i>B. cinerea</i>.