In this study, we isolate helvolic acid, an antibiotic metabolite, from the rice sheath rot pathogen Sarocladium oryzae. The fungus is cultured in potato-sucrose broth. The metabolite is extracted by ethyl acetate, and its antibiotic activity is tested with Bacillus subtilis. Helvolic acid is soluble in chloroform, acetone; ethyl acetate, methanol, ethanol, and alkali water. The substance is stable at an active temperature of 22°C-100°C and is also active at various hydrogen ion levels (pH 3-11). Also, helvolic acid is identified with thin-layer chromatography and further characterized by UV, IR, NMR, and Mass spectroscopy. The toxic effects of helvolic acid on seedlings of Graminae include growth retardation and chlorosis. These effects are reduced about 40% by treating with Hoagland's solution and can be reduced to around 30% by treating with magnesium solution.
|頁（從 - 到）||251-256|
|期刊||Botanical Bulletin of Academia Sinica|
|出版狀態||Published - 1997 一月 1|
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