| Budget Amount *help |
¥27,000,000 (Direct Cost: ¥27,000,000)
Fiscal Year 1987: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1986: ¥4,000,000 (Direct Cost: ¥4,000,000)
Fiscal Year 1985: ¥21,000,000 (Direct Cost: ¥21,000,000)
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| Research Abstract |
Natural hatching stimuli of potato cyst nematode. a) The bioassay, required for purification,was improved by pretreatment of the nematode cysts and eggs as well as by control of the pH (3-4)of the test solution. b) Active starting material was prepared by extraction of dried roots of tomato with dry ice-acidified water and absorption of the aqueous extracts on Amberlite XAD-2 followed by desorption with acetone. The resulting powdered raw material (active at 10^<-5> g/ml) was easily soluble in water and stable in an aqueous solution only with pH 2-8. c) The active raw material (34.6 g), obtained from the dried roots (24 kg), was purified by repeated chromatography (column, solvent; Amberlite XAD-2, water; Sephadex G-15, water; Sephadex-10, water; Toyopearl HW-40c, water; Toyopearl HW-40s, water) and by HPLC over -Bondapak C_<18> (water-methanol) to give an active fraction (0.1 mg) with activity of 10^<-9 -10> g/ml. Further purification will be required. d) The active substance is presumed to be neither polypeptides nor polysaccharides (by dialysiswith Cellophane) but triterpene-like substance(s) (by measurement of the ^1H NMR spectrum) with molecular weight below 1000 (by gel chromatography over Sephadex G-10) and with double bond(s) and hydrophilic functions.
Hatching stimuli of soybean cyst nematode. a) The total synthesis of the natural hatching stimulus, glycinoeclepin A (GEA), of the nematode has been achieved, indicating that GEA is indeed the active substance itself. b) The prtial synthesis will be completed in the near future: cycloastragalol, obtained easily from Chinese drug "Tragacantha", was transformed into two compounds, one having the same C and D rings as GEA and another the same A and B rings as GEA. Hatching acivity of most of these synthetic intermediates will be examined in the coming spring to elucidate what moieties are required for the biological activity.
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