Pegriseofamines A−E: Five cyclopiazonic acid related indole alkaloids from the fungus Penicillium griseofulvum

Five new cyclopiazonic acid related indole alkaloids, pegriseofamines A-E (1-5), were isolated from the fungus Penicillium griseofulvum. Their structures and absolute configurations were determined by NMR, HRESIMS, quantum-chemical calculation, and X-ray diffraction experiments. Among them, pegriseofamine A (1) possesses an undescribed 6/5/6/7 tetracyclic ring system generated by the fusion of an azepine and an indole unit via a cyclohexane, and the postulated biosynthetic origin of 1 was discussed. Compound 4 could relieve liver injury and prevent hepatocyte apoptosis in ConA-induced autoimmune liver disease.