36 BIOSYNTHESIS OF TRICHOTHECIN AND RELATED SUBSTANCES
Details
From the unsaponifiable fraction of the fermentation materials of Trichothecium roseum 6157, a trichothecin producing fungus, were isolated four sesquiterpenes, III, XIV, XVII, and XXIV, all of which are thought to be biogenetically related to trichothecin (I). Their structures were determined by spectral properties of the various derivatives and/or by chemical interrelation with known compounds. Feeding experiments of [4(R), 4-^3H-2-^<14>C] MVA and the subsequent degradation of the resulting trichothecolone showed that one of the radioactive carbon atoms (C-2 of MVA) is located at C-8 as shown in XXV, which is in disagreement with the earlier work. Tritium-labelled trichodiene (XXXIII) was prepared and fed to T. roseum 6157. The radioactive trichodiene was shown to be incorporated into the trichothecolone, giving an evidence that the hydrocarbon, trichodiene, is the intermediate in the biosynthesis of trichothecin. Possible biosynthetic route is given in the scheme.
