Phytotoxic Metabolites Isolated from Aspergillus sp., an Endophytic Fungus of Crassula arborescens .

Aspergillus sp., an endophytic fungus isolated from Crassula arborescens , displayed potent inhibitory activity against the seed germination of Arabidopsis thaliana . The bioactivity-guided fractionation of the culture extract of Aspergillus sp. MJ01 led to the isolation of nine compounds, including one previously undescribed furanone, namely aspertamarinoic acid ( 1 ), and eight known compounds, (-)-dihydrocanadensolide ( 2 ), kojic acid ( 3 ), citreoisocoumarin ( 4 ), astellolide A ( 5 ), astellolide B ( 6 ), astellolide G ( 7 ), cyclo -N-methylphenylalanyltryptophenyl ( 8 ) and (-)-ditryptophenaline ( 9 ). In the evaluation of the phytotoxic activities of compounds 1 - 9 , the results suggested that 1 and 5 showed significant inhibitory activity on the seed germination of A. thaliana . This is the first report to disclose the phytotoxic activity of these compounds.