68(PA2-8) Cercospora cruentaの生産するアブシジン酸関連物質の立体構造と生合成(ポスター発表の部)

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New analogs of abscisic acid (ABA), a plant hormone, were separated from the broth of a fungus ; Cercospora cruenta. The stereochemistry of the new ABA analogs were investigated by chemical reactios, spectral analyses and syntheses. Also, the biosynthetic pathway of ABA in C. cruenta was clarified. 1) From the filtrate of the broth of C. cruenta were separated (1'R,4'R) and (1'R,4'S)-(2Z,4E)-4'-hydroxy-γ-ionylideneacetic acids (γ-acids), (1'S,4'S)-(2Z,4E) and (2E,4E)-1',4'-dihydroxy-γ-acids and 3'-hydroxy-γ-acids as a mixture of four stereoisomers. 2) The stereochemistry of 4'-hydroxy-γ-acids was elucidated by examining the downfield shift of gem-methyl protons by the 1,3-diaxial relationship to the 4'-hydroxyl group on ^1H-NMR spectra. 3) 3'- and 4'-Hydroxy-γ-acids were synthesized from 3'-THPoxy and 4'-acetoxy-γ-cyclocitrals, prepared by the 2,3-sigmatropic reaction with N,N-dimethylacetonitrile. 4) From the mycelium of C. cruenta was separated (+)-(R)-(2Z,4E)-γ-ionylideneethanol, which was synthesized from (-)-(R)-γ-ionone. GLC analysis of the mycelium extract showed the presence of a trace amount of (2Z,4E)-γ-acid. 5) (2-^<14>C)-(2Z,4E)-γ-ionylideneethanol and (2-^<14>C)-(2Z,4E)-γ-acid were converted to (2-^<14>C)-ABA via the intermediates: (2-^<14>C)-(2Z,4E)-4'-hydroxy-γ-acid and (2-^<14>C)-(2Z,4E)-1',4'-dihydroxy-γ-acid, in C. cruenta.
天然有機化合物討論会の論文
1987-07-25