Shennongoverrins A-D, anti-Fusarium phenalenone derivatives from the endophytic fungus Pencillium verrucisporum (SNY12-1).

Four new phenalenone derivatives, shennongoverrins A-D (1-4), were isolated from the endophytic fungus Penicillium verrucisporum (strain SNY12-1). Notably, compound 1 possessed a unique carbon framework distinguished by an uncommon 5/6/6/6/5 fused ring system, incorporating an additional five-membered ring. The structural elucidation of these compounds was achieved through comprehensive analyses, including NMR, MS, DFT calculations, CD, and single-crystal X-ray diffraction. Furthermore, a plausible biosynthetic pathway for compounds 1-16 was proposed. In antifungal bioassays targeting four Fusarium species, shennongoverrin A (1) demonstrated inhibitory activity against Fusarium graminearum with a MIC of 1.56 μg/mL. Shennongoverrins BD (2-4) exhibited inhibitory effects against both F. graminearum and Fusarium oxysporum f. sp. cubense, with MIC values of 3.13 μg/mL. Additionally, (±)-aurantionone A (9, 10) showed inhibitory activity against four Fusarium pathogens, with MIC values of 1.56, 1.56, 3.13, and 3.13 μg/mL, respectively. Compounds 1-10 showed better antifungal activities compared to carbendazim (positive control). These findings indicated that shennongoverrin A and its derivatives represented promising lead compounds for the development of novel fungicidal agents.