Two new isocoumarins from cave-derived Metarhizium anisopliae NHC-M3-2

Extracting extracts of secondary metabolites from the karst cave fungus Metarhizium anisopliae NHC-M3-2 from the Yilingyan Scenic Area in Guangxi. Ten compounds were isolated and purified from fungal secondary metabolites using thin-layer chromatography and high-performance liquid chromatography. 7-Hydroxy-3-hydroxypropyl-5,6-dimethylisochrome-1-one (1) and 7-hydroxy-3,5,6-trimethyl-isochromen-1-one (2) were new isocoumarin compounds, N-acetyl phenylalanine (3), chaetosumin J (4), 2-one-13-hydroxy-3,5,8,7(11)-eudesmatetraen-12,8-olide (5), 1H-indole-3-carboxaldehyde (6), irpexolaceus B (7), irlactin L (8), cytochalasin K (9), and helvolic acid (10), a total of 8 known compounds. The structure of the compound was determined using methods such as NMR and mass spectrometry. The tumor cytotoxicity of the compound was evaluated using the CCK-8 method. The results showed that the IC₅₀ of compound 2 on HepG2 cells was 29.83 µmol·L^-1, and compound 9 on HCT116 cells was 27.44 µmol·L^-1.