| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 1998: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1997: ¥2,300,000 (Direct Cost: ¥2,300,000)
|
|---|
| Research Abstract |
Penicillium simplicissimum ATCC 90288, when grown on okara (the insoluble residue of whole soyabean), produces insecticidal indole alkaloid okaramines, which has a unique structure. The structure prompted us to clarify the biogenesis of okaramines. The strain ATCC 90288 did not produce okaramines in a Czapek medium, but the methanol extract of okara supplemented to the Czapek medium promoted the production of okaramines, strongly suggesting that a certain factor in okara promoted the production of okaramines by the fungus.
To clarify the factor an assay system for the detection of the factor was first established. The produced amounts of okaramines A and B in mycelia of the strain were measured by HPLC.Using this assay system, we tried to isolate the promoting factor in okara, and some results are obtained as follows.
1) The metanol extract of okara was extracted with ethyl acetate and n-butanol successively, and the aqueous residue exhibited the promoting activity, indicating that the factor was water soluble substance.
2) The aqueous residue was chromatographed on Dowex 1, and the active faction (0.5-4 NHCl eluates) was further chromatographed on Dowex 50W.The 0.5*4 N NH_4OH eluates showed the activity. Purification of these factions by colume chromatography on Sephadex LH-20 afforded a partially purified faction, which exhibited the activity in the concentration of ca. 30 ppm. This fraction seemed to contain several compounds which are positive to Ninhydrin reagent.
3) Uridine has already isolated as an active substance which weakly promotes the production of okaramines by Penicillium simplicissimum ATCC 90288.
|
