Biosynthesis of the antibiotic verrucarin E use of [1‐ 13 C]‐, [2‐ 13 C]‐, [1,2‐ 13 C]‐ and [2‐ 13 C, 2‐ 2 H 3 ]‐acetates. Verrucarins and roridins, 37th communication [1]

The origin of the carbon skeleton of verrucarin E (1) from acetate as precursor is confirmed. Incorporation studies with [1,2‐ 13 C]‐acetate have demonstrated that two acetoacetate units couple together as shown in pattern A (Scheme 2) and not as in B . Analysis of the deuterium distribution in both verrucarin E (1) isolated after the incorporation of [2‐ 13 C,2‐ 2 H 3 ]‐acetate and in sodium acetate obtained after Kuhn ‐ Roth oxidation of the metabolite demonstrated that C(7) is derived from the starter unit of one of the acetoacetate moieties. The deuterium exchange in verrucarin E (1) occurring during fermentation was investigated.