FR-900403

FR900403 (I) was isolated from the culture filtrate of Kernia sp.The structure of I was determined by ¹H NMR spectroscopic anal.FR900403 exhibits antimicrobial activity against Candida albicans, but not against filamentous fungi.The MIC value of FR900403 against C. albicans FP633 was 0.4 μg/mL in Eagle min. essential medium at 37° under 5% CO₂ atmosphere.FR900403 was effective against a generalized infection of C. albicans FP633 in mice at a dose of 10 mg/kg.It was not lethal to mice at a dose of 320 mg/kg when i.v. administered.