Phytotoxic Metabolites Isolated from <i>Aspergillus</i> sp., an Endophytic Fungus of <i>Crassula arborescens</i>

Abstract

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.

Keywords

• <i>Crassula arborescens</i>
• endophytic fungus
• <i>Aspergillus</i> sp.
• phytotoxic activity