Cyclohexene, Diketopiperazine, Lactone and Phenol Derivatives from the Sea Fan-derived Fungi Nigrospora sp PSU-F11 and PSU-F12

Nigrosporanenes A (1) and B (2), two new cylohexene derivatives, and tyrosol (3) were isolated from the sea fan-derived fungus Nigrospora sp. PSU-F11, whereas five known compounds: 4-hydroxybenzoic acid (4), aplysiopsene D (5), 3-isochromanone (6), (-)-drimenin (7) and diketopiperazine derivative (8), were obtained from the fungus Nigrospora sp. PSU-F12. Their structures were established by spectroscopic evidence. We also tested their cytotoxic (on African green monkey kidney fibroblast and breast cancer cells), antioxidant (in the DPPH assay), and antibacterial (against the standard Staphylococcus aureus ATCC 25923 and methicillin-resistant S. aureus) activities.