Roridin biosynthesis

Wagner-Meerwein rearrangements are prevalent in the biosynthesis of terpenoids and steroids [21], An example can be represented by the concerted rearrangements (1,3-hydride and 1,2-methyl shift) that lead to the biosynthesis of trichodiene, an intermediate of the terpenes verrucarin A and roridin A (Section 3.2.24) (Figure 1.18). 

Figure 3.129 Trichothecene biosynthesis in other genera than Fusarium proposed pathway for type B trichothecene trichothecin 372, type C trichothecene crotocin 373, and type D macrolide trichothecenes roridin A 374 and verrucarin A 375.

For the elucidation of the biosynthesis of the macrocyclic part of the verrucarins and roridins, a number of feeding experiments were carried out by adding likely and H-labeled precursors to cultures of Myrothecium species. In order to determine the distribution of the radioactivity, the isolated metabolites were subjected to several degradation reactions (Achini et ai, 1974 Muller et ai, 1975a Tamm, 1968). 

Muller, B., and Ch. Tamm Biosynthesis of the Verrucarins and Roridins. Part 4. The Mode of Incorporation of (3R)-[(5R)-5- H]-Mevalonate into Verrucarol. Evidence for the Identity of the C(1 l)-Hydrogen Atom of the Trichothecane Skeleton with the (5R)-Hydrogen Atom of (3R)-Mevalonic Acid. Helv. Chim. Acta 58, 483 (1975). 

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