| Budget Amount *help |
¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2002: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2001: ¥500,000 (Direct Cost: ¥500,000)
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| Research Abstract |
New convulsive compounds, brasiliamides A and B, were isolated by activity-guided fractionation from okara fermented with a soil isolate of Penicillium brasilianum Batista JV-379. Their structures were elucidated on the basis of spectral and chemical evidence and by X-ray crystallography of the hydrogenated product of brasiliamide B. In the ^1H- and ^<13>C-NMR spectra of brasiliamide B, the signals were complicated, all being doubled or broadened in several deuterated solvents at room temperature. The conformational change of brasiliamide B was clarified as the rotational isomerization of amide bonds in solution by NMR measurements at various temperatures. Four rotamers of brasiliamide B at two amide bonds were presented at -60℃ in CDCl_3, whereas only two isomers were apparent at room temperature, owing to rapid rotation of one of the amide bonds. Additionally, three new brasiliamides congeners, brasiliamides C, D and E were isolated and their structures were determined. Brasiliamides A, B and C respectively showed convulsive activity against silkworms with ED_<50> values of 300, 50 and 300 μg/g of diet.
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