Five New Cytotoxic Metabolites from the Marine Fungus Neosartorya pseudofischeri

摘要

The marine fungus Neosartorya pseudofischeri was isolated from Acanthaster planci from the South China Sea. In a preliminary bioactivity screening, the crude methanol extract of the fungal mycelia showed significant inhibitory activity against the Sf9 cell line from the fall armyworm Spodoptera frugiperda. Five novel compounds, including 5-olefin phenylpyropene A (>1), 13-dehydroxylpyripyropene A (>4), deacetylsesquiterpene (>7), 5-formyl-6-hydroxy-8-isopropyl-2- naphthoic acid (>9) and 6,8-dihydroxy-3-((1E,3E)-penta-1,3-dien-1-yl)isochroman-1-one (>10), together with eleven known compounds, phenylpyropene A (>2) and C (>3), pyripyropene A (>5), 7-deacetylpyripyropene A (>6), (1S,2R,4aR,5R,8R,8aR)-1,8a-dihydroxy-2-acetoxy-3,8-dimethyl-5- (prop-1-en-2-yl)-1,2,4a, 5,6,7,8,8a-octahydronaphthalene (>8), isochaetominine C (>11), trichodermamide A (>12), indolyl-3-acetic acid methyl ester (>13), 1-acetyl-β-carboline (>14), 1,2,3,4-tetrahydro-6-hydroxyl-2-methyl-l,3,4-trioxopyrazino[l,2-a]-indole (>15) and fumiquinazoline F (>16), were obtained. The structures of these compounds were determined mainly by MS and NMR data. The absolute configuration of >9 was assigned by the single-crystal X-ray diffraction studies. Compounds >1–>11 and >15 showed significant cytotoxicity against the Sf9 cells from S. frugiperda.