The biosynthesis of polyacetylenes. 2. Origin of the carbon atoms

Abstract

Nemotinic acid incorporating radioactivity from l-C14-acetate has been completely degraded to show the labeling pattern. Nemotinic acid, with 11 C atoms, is formed from 6 molecules of an acetic acid derivative, linked head to tail, with elimination of the terminal methyl group, and odyssic acid is probably formed similarly without demethylation. The natural acetylenes are formed within the context of the reactions of fatty acid synthesis, the triple bonds arising directly or indirectly from -CO- CH2- groups. With the addition of the triple-bond-forming mechanism and the demethylation reaction, the reactions of fatty acid synthesis will account for most features of the structure of naturally occurring acetylene derivatives.