Abstract
Pefurazoate, pent-4-enyl N-furfuryl-N-imidazol-1-ylcarbonyl-DL-homoalaninate, was highly toxic to wide range of phytopathogenic fungi including Ascomycetes, Basidiomycetes and Deuteromycetes, but less toxic to Phycomycetes. Although the compound hardly inhibited spore germination of Fusarium moniliforme, Cochliobolus miyabeanus and Pyricularia oryzae at 100μg/ml, germ tubes of treated spores were swollen, abnormally branched and shorten at 0.1-1.0μg/ml. Gas chromatographic analysis indicated that ergosterol biosynthesis of F. moniliforme was strongly suppressed and the concomitant accumulation of 24-methylene-dihydrolanosterol, obtusifoliol and other unknown substances were observed. This result suggested that pefurazoate particularly inhibited the demethylation at C-14 position of 24-methylenedihydrolanosterol in sterol biosynthetic pathway. Pefurazoate also affected the production of gibberellin-like substances in culture liquid of F. moniliforme at a low concentration which hardly affected the inhibition of mycelial growth.
