New azaspirene derivatives from marine-derived fungus Aspergillus micronesiensis NF666

Azaspirene derivatives are widespread natural products in fungi. Here we reported five new azaspirenes A-E (1–5) from the marine mud-derived endophytic fungus Aspergillus micronesiensis NF666. Their structures were unambiguously determined by an extensive analysis of HRESIMS and NMR data. All compounds were evaluated on antimicrobial activities against five pathogens by the agar diffusion method. Moreover, a plausible biosynthetic pathway of azaspirenes A (1) is proposed in this work.