Biosynthesis of Cytochalasans. Part 4. The mode of incorporation of common naturally‐occurring carboxylic acids into cytochalasin D

Utilization of sodium [1‐ 14 C]‐, [2– 14 C]‐, and [1,2‐ 13 C]‐acetates, [1‐ 14 C]‐, [1‐ 13 C]‐, or [2‐ 14 C]‐propionates, [1‐ 14 C]‐or [2‐ 14 C]‐malonates, of [1‐ 14 C]‐ or of [1‐ 14 C]‐myristic acid, or of [1‐ 14 C]‐ and [1‐ 14 C]‐palmitic acid in the biosynthesis of cytochalasin D ( 1 ) by Zygosporium masonii was determined by degradation studies or by carbon magnetic resonance spectroscopy. The precursors were incorporated primarily via the acetate‐malonate pathway to generate 1 from nine intact acetate units, eight of which are coupled in a head to tail fashion to form the C 16 ‐polyketide moiety.