Diverse secondary metabolites with anti-fungal activity from endophytic fungus Pezicula neosporulosa VDB39

Crop diseases caused by plant pathogenic fungi pose a threat to agricultural productivity and quality. Secondary metabolites from microorganisms (microbial antagonists), as a green biocide approach, have long attracted considerable attention. To explore bioactive natural products (NPs) from endophytic fungi for combating Alternaria fruit rot, a solid fermentation of Pezicula neosporulosa VDB39, isolated from Vaccinium dunalianum Wight, was investigated. Consequently, sixteen constituents (1−16), including six previously unreported cuparene sesquiterpenes neosporudins A-F (1−6), a new isocoumarin derivative neosporumarin A (7), and a new chlorophenol glycoside neosporuloside A (8), were obtained. Their structures were assigned via vast spectroscopic methods, DP4 + analysis, ECD, and DFT calculations. Relevant biological experiments on six agricultural disease fungi found that four ingredients (6, 9, 11, and 12) exhibited significant anti- A. brassicicola activities with MIC values of 3.9–7.8 μ g/mL. Notably, treatment with 12 (MICs = 1.9–3.9 μ g/mL) caused morphological damage to A. brassicicola , as observed by SEM. The interaction mechanism of the target compound 12 binding to 1,3- β -glucan synthase Fks1 in cell walls was further verified through molecular docking studies. Furthermore, the application of compound 12 demonstrated protection and curation against Alternaria fruit rot in vivo , providing a novel possibility for postharvest blueberry preservation. • Sixteen compounds from Pezicula neosporulosa , including eight novel ones (1−8). • The planar and stereo structures were assigned via NMR, HRMS, DP4 + , ECD, and DFT. • Compounds 6, 9, 11, and 12 showed significant anti- A. brassicicola activities. • 12 can damage A. brassicicola cell wall by inhibiting 1,3- β -glucan synthase Fks1. • The application of 12 can prevent Alternaria fruit rot of postharvest blueberries.