ニバレノール(マイコトキシン)の代謝と毒性機構に関する研究 ： 第一報．ニバレノールの単離精製と新代謝物 ； 脱エポキシニバレノールの同定

Abstract

Large amounts of two mycotoxins, nivalenol and fusarenon-X were produced from Fusarium graminearum F-1465 cultured on pressed barley. The centrifugal partition chromatography (CPC) using two-phase solvent systems n-butanol-water and chloroform-methanol-water could be applied to a preparative purification of nivalenol and fusarenon-X. Starting from the Fusarium grown on 1 kg of pressed barley substrate, 0.34 g of nivalenol and 0.78 g of fusarenon-X were obtained by recrystallization of CPC fraction from hot methanol. Fusarenon-X was converted to nivalenol by alkaline hydrolysis giving to 0.55 g of crystalline nivalenol. A new metabolite of nivalenol was detected in the feces of rats when nivalenol was administered orally. The new metaboite was identified as 3, 4, 7, 15-tetrahydroxytrichothec-9, 12-dien-8-one, or deepoxynivalenol, on the basis of mass spectrometry and ¹H and ¹³C nuclear magnetic resonance spectroscopy. In repeated oral administration, the deepoxy metabolite was detected in feces at 80% and in urine at 1% of total dose, and the parent compound was detected in feces at 7% and in urine at 1%, respectively.