New convulsive compounds, brasiliamides A and B, from Penicillium brasilianum batista JV-379.
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 degrees 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 microg/g of diet.
D000818:Animals; D001681:Biological Assay; D012831:Bombyx / Q000378:metabolism; D002850:Chromatography, Gel; D003292:Convulsants / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D018360:Crystallography, X-Ray; D004149:Dioxoles / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D008958:Models, Molecular; D008968:Molecular Conformation; D019906:Nuclear Magnetic Resonance, Biomolecular; D010407:Penicillium / Q000737:chemistry* / Q000378:metabolism; D011719:Pyrazines / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D012988:Soil Microbiology; D013237:Stereoisomerism
D003292:Convulsants; D004149:Dioxoles; D011719:Pyrazines; C472985:brasiliamide A; C472986:brasiliamide B