Über die Biosynthese des Antibioticums Verrucarin E. Verrucarine und Roridine, 19. Mitteilung [1]

The incorporation of nine 14C‐labelled, assumed biosynthetic precursors of verrucarin E (1) formed by Myrothecium verrucaria have been measured. The antibiotic and 3‐acetyl‐4‐methyl‐pyrrole (3) derived from it were oxidized, and the radioactivity of four of the seven C‐atoms determined. It has been found that the carbon skeleton of verrucarin E does not originate from proline, glutamic acid and its biogentic equivalents nor from 5‐amino‐levulinic acid, but is built up from four acetate units with loss of one carboxyl C‐atom. These results are rationalized by proposing a biogenetic pathway for verrucarin E.