5-Hydroxycyclopenicillone, a New β-Amyloid Fibrillization Inhibitor from a Sponge-Derived Fungus Trichoderma sp. HPQJ-34.

A new cyclopentenone, 5-hydroxycyclopeni cillone (), was isolated together with three known compounds, -turmerone (), citreoisocoumarin (), and 6-O-methyl-citreoisocoumarin (), from a culture of the sponge-derived fungus sp HPQJ-34. The structures of - were characterized using comprehensive spectroscopic analyses. The absolute configuration of was determined by comparison of electronic circular dichroism (ECD) spectra with literature values used for the reported analogue, cyclopenicillone (), which was not isolated in this research. Compound 1 was shown to scavenge 2,2-diphenyl-1-picrylhydrazyl free radicals, and decrease β-amyloid (Aβ) fibrillization in vitro. Moreover, 1 significantly reduced H₂O₂-induced neurotoxicity in SH-SY5Y cells. These findings suggested that compound 1, a newly discovered cyclopentenone, has moderate anti-oxidative, anti-Aβ fibrillization properties and neuroprotective effects, and might be a good free radical scavenger.