|Budget Amount *help
¥1,800,000 (Direct Cost : ¥1,800,000)
Fiscal Year 1991 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1990 : ¥1,300,000 (Direct Cost : ¥1,300,000)
1. By using silica gel column chromatography, two toxic substances were isolated from the culture filtrate of the strain of Glomerella cingulata, the tea brown blight fungus given from Shizuoka Tea Experimental Station.
2. These two toxic substances were identified to be phenylacetic acid and indolacetic acid by the measurement and elucidation of physics-chemical properties, mass spectral data, ^1H-NMR spectral data, ^<13>C-NMR spectral data and so on of these two substances.
3. The strain of Pestalotia longiseta, the tea gray blight fungus were cultivated and a phytotoxic substance was isolated from the culture filtrate. However, the toxic substance was identified to be oxysporone which had already been isolated as a phytotoxin from this strain by Ando and Nagata. The synergistic phytotoxic activity of oxysporone and phenylacetic acid and indolacetic acid was examined, but that activity was negligible,
4. The strain of the tea brown blight fungus given from National Research Institute of Vegetables, Ornamental Plant and Tea was stationarily cultivated and the ethyl acetate extracted neutral fraction of the culture filtrate showed the antifungal activity against the tea gray blight fungus. The active substance was isolated and the chemical structure was elucidated by the physico-chemical properties and mass and NMR spectral data. The substance was identified as citreopyrone which had already been isolated as a metabolite of Penicillium.
5. Four acidic phytotoxic substances were isolated from the culture filtrate of the tea gray blight fungus, but the phytotoxic activity of these substances was lower than that of oxysporone.