Abstract
Chloroform and ethyl acetate extracts of Aspergillus fischeri TISTR 3272 showed good growth inhibitory activity on Mimosa pigra and Echinochloa crus-galli. Bioassay-directed fractionation of the active extracts led to the isolation of five known compounds, (+)-terrein (1), (−)-6-hydroxymellein (2), two diketopiperazines (cyclo-(S-Pro-S-Leu) (3) and cyclo-(S-Pro-S-Val) (4)) and butyrolactone I (5). Compounds 2–5 were reported for the first time in this fungus. Their structural determinations were based on analyses of spectroscopic data and their weed growth inhibitory effects were assessed.
Acknowledgements
This work was supported by a grant from Silpakorn University Research and Development Institute, Thailand. The authors wish to thank the Thailand Institute of Scientific and Technological Research (TISTR), for providing fungal cultures, and National Weed Science Research Institute, Department of Agriculture, Thailand, for providing seeds of E. crus-galli and M. pigra.