Abstract: Investigation of the entomogenous fungus Setosphaeria rostrate LGWB-10 from Harmonia axyridis led to the isolation of four new isocoumarin derivatives, setosphlides A-D (1-4), and four known analogues (5-8). Their planar structures and the relative configurations were elucidated by comprehensive spectroscopic methods. The absolute configurations of isocoumarin nucleus for 1-4 were elucidated by their ECD spectra. The C-10 relative configurations for the pair of C-10 epimers (1 and 2) were established by comparing the magnitude of the computed ¹³C NMR chemical shifts (Δδ_calcd.) with the experimental ¹³C NMR values (Δδ_exp.) for the epimers. All of the isolated compounds (1-8) were evaluated for their cytotoxicities against four human tumor cell lines MCF-7, MGC-803, HeLa, and Huh-7.

Key words: Entomogenous fungus, Setosphaeria rostrate, Isocoumarin, Absolute configuration

摘要： Investigation of the entomogenous fungus Setosphaeria rostrate LGWB-10 from Harmonia axyridis led to the isolation of four new isocoumarin derivatives, setosphlides A-D (1-4), and four known analogues (5-8). Their planar structures and the relative configurations were elucidated by comprehensive spectroscopic methods. The absolute configurations of isocoumarin nucleus for 1-4 were elucidated by their ECD spectra. The C-10 relative configurations for the pair of C-10 epimers (1 and 2) were established by comparing the magnitude of the computed ¹³C NMR chemical shifts (Δδ_calcd.) with the experimental ¹³C NMR values (Δδ_exp.) for the epimers. All of the isolated compounds (1-8) were evaluated for their cytotoxicities against four human tumor cell lines MCF-7, MGC-803, HeLa, and Huh-7.

关键词: Entomogenous fungus, Setosphaeria rostrate, Isocoumarin, Absolute configuration