Biosynthesis of Trichothecenes and Apotrichothecenes
摘要:
Fusarium culmorum produces two major trilchothecenes, 3-acetyldeoxynivalenol and sambucinol, and some minor apotrichothecenes. It was desired to investigate if during their biosynthesis a C-11-keto intermediate was involved. To verify this postulate, trichodiene, a known precursor to trichothecenes, was synthesized with two deuteriums at C-11 and one at C-15. It was then fed to F. culmorum cultures, and the derived metabolites were purified and analyzed. The results ruled out the involvement of an 11-keto intermediate but revealed two novel apotrichothecenes. The characterization of their structures suggested that one of the 2-hydroxy-11 alpha-apotrichothecene stereoisomers (2 alpha or 2 beta) could be converted to sambucinol. These apotrichothecenes were therefore synthesized labeled specifically with two deuteriums at C-4 and C-15 and fed to F. culmorum cultures. Indeed, the result established for the first time that 2 alpha-hydroxy-11 alpha-apotriehothecene was a precursor to sambucinol. A biosynthetic scheme for the production of trichothecenes and apotrichothecenes is described.
Biosynthesis of Trichothecenes and Apotrichothecenes
摘要:
Fusarium culmorum produces two major trilchothecenes, 3-acetyldeoxynivalenol and sambucinol, and some minor apotrichothecenes. It was desired to investigate if during their biosynthesis a C-11-keto intermediate was involved. To verify this postulate, trichodiene, a known precursor to trichothecenes, was synthesized with two deuteriums at C-11 and one at C-15. It was then fed to F. culmorum cultures, and the derived metabolites were purified and analyzed. The results ruled out the involvement of an 11-keto intermediate but revealed two novel apotrichothecenes. The characterization of their structures suggested that one of the 2-hydroxy-11 alpha-apotrichothecene stereoisomers (2 alpha or 2 beta) could be converted to sambucinol. These apotrichothecenes were therefore synthesized labeled specifically with two deuteriums at C-4 and C-15 and fed to F. culmorum cultures. Indeed, the result established for the first time that 2 alpha-hydroxy-11 alpha-apotriehothecene was a precursor to sambucinol. A biosynthetic scheme for the production of trichothecenes and apotrichothecenes is described.