New convulsive compounds, brasiliamides A (1) and B (2), 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 2. In the 1H- and 13C-NMR spectra of 2, the signals were complicated, all being doubled or broadened in several deuterated solvents at room temperature. The conformational change of 2 was clarified as the rotational isomerization of amide bonds in solution by NMR measurements at various temperatures. Four rotamers of 2 at two amide bonds were presented at −60°C in CDCl3, whereas only two isomers were apparent at room temperature, owing to rapid rotation of one of the amide bonds. Brasiliamides A and B respectively showed convulsive activity against silkworms with ED50 values of 300 and 50 μg/g of diet.
通过活性引导分馏,从用巴西青霉 Batista JV-379 土壤分离物发酵的豆渣中分离出新的惊厥化合物巴西酰胺 A (1) 和 B (2)。它们的结构是根据光谱和化学证据以及2的氢化产物的X射线晶体学阐明的。在2的1H-和13C-NMR谱中,信号很复杂,在几个氘代中全部加倍或加宽。室温下的溶剂。通过在不同温度下的NMR测量,2的构象变化被阐明为溶液中酰胺键的旋转异构化。在-60°C 的CDCl3 中,两个酰胺键上的2 的四个旋转异构体出现,而由于其中一个酰胺键的快速旋转,在室温下只有两个异构体是明显的。 Brasiliamides A 和 B 分别对蚕表现出惊厥活性,ED50 值为 300 和 50 μg/g 饲料。