from paddy-fields in the north of Iran. It was shown that it excreted broad-spectrum
antibacterial and antifungal substance in culture medium. Bioassay-guided fraction of the
culture medium of the F. ambigua led to isolation of a novel antimicrobial substance, which
was named parsiguine, that exhibited antifungal and antibacterial activities. The structure of
parsiguine was determined by spectroscopic methods, including NMR, MS, IR, and UV.