48 分子内Diels-Alder反応を経る天然物生合成経路の可能性 : ベーテノンBおよびソラナビロンAの生合成(口頭発表の部)

概要

論文の詳細を見る
Recently, the reduced polyketide compounds, which are possibly biosynthesized via intramolecular Diels-Alder reaction, have been found in the metabolites of fungi and Streptomyces. Those possess decalin moiety,and a double bond and two ajacent substituents in one ring of decalin. To investigate this possibility, the biosynthetic pathway of two phytotoxins, betaenoe B(1) and solanapyrone A(2) were studied. 1. Betaenone B(1) The biosynthetic origin of oxygen atoms in 1 was established by feeding experiment of [1-^<13>C,^<18>O_2]acetate. The result was supported by the accumulation of the intermediate, probetaenoe I(5) in the cytochrome P-450 inhibitor treatment of P. betae. The radioactive (5) was efficiently converted to 1 (6.02%) in P. betae. 2. Solanapyrone A(2) The biosynthtic building block of 2 were examined by feeding experiments with ^<13>C-labelled precursors. The results showed 2 was octaketide with two C_1 units. Participation of Diels-Alder reaction in the biosynthesis of 2, was suggested by the isolation of solanapyrone D(9), which was a diastereomeric isomer of 2. The absolute configulations of 2 and 9 imply the enzyme recoginizes loosely the diene moiety.
天然有機化合物討論会の論文
1988-09-26