Cyclopiazonic Acid and Okaramine Analogues, Including Chlorinated Compounds, from YT-1

Eight new cyclopiazonic acid (-) and five new okaramine (-) alkaloids together with 13 known compounds were isolated from the fungus YT-1. Compounds , , , , , , and were chlorinated indole alkaloids. The structures of compounds - were elucidated by HRESIMS and NMR spectroscopic data. Their relative and absolute configurations were established by -based configuration analysis, NOESY, NOEDIFF experiments, ECD spectroscopic data, and biogenetic considerations. Compound inhibited the growth of with an MIC value of 6.3 μg/mL. Compounds - exhibited strong insecticidal capacity against the third instar larvae of silkworm and cotton bollworm (LD: ≤7.56 μg/g). At 40 μM, compound showed obvious neuroprotection to the PC12 cells with 6-OHDA treatment.