Oxindole alkaloids from the fungus Penicillium commune DFFSCS026 isolated from deep-sea-derived sediments

Cyclopiamides B–J (1–9), nine new oxindole alkaloids were isolated from the deep-sea-derived fungus Penicllium commune DFFSCS026. Their structures were elucidated by extensive spectroscopic data analysis. Compound 4 contains a rare 2H-pyrrole[2,1-b]pyridine unit, and compounds 8 and 9 are complex polycyclic and polyhydroxy alkaloids. The absolute configurations of 6 and 8 were established by molecular mechanics calculation, quantum chemical computations, and single crystal X-ray diffraction analysis, respectively.