Ergoline Biosynthesis in Cell-Free Extracts

Cell-free conversion of the precursors into the tetracyclic clavines and chanoclavine I and II was obtained by Cavender and Anderson (1970). Incubation of [ Cjtryptophan, isopentenyl pyrophosphate, methionine, ATP, and liver concentrate (mixture of cofactors) with the 60-80% ammonium sulfate fraction from C. purpurea PRL 1970 for 12 hr gave radioactive chanoclavine I and II, agroclavine, and elymoclavine. Conversion was 0.15% for chanoclavine I and II. 

Abe s group (Abe, 1971 Ohashi et al., 1972b) obtained cell-free biosynthesis of setoclavine from [ C]tryptophan, mevalonate, and methionine in crude extracts from two Claviceps strains. Their system was considerably more efficient with 4.4% conversion in 3 hr. The product was identified by cocrystallization with authentic material. The system also converted (7), but not (6) into setoclavine. Abe s group also studied several other conversions in cell-free systems (Abe, 1971 Ohashi and Abe, 1970 Ohashi et ai, 1970a,b, 1972a). 

---