Biosynthesis of cochlioquinones

Abstract

The biosynthesis of cochlioquinones (1) and (2) was studied by isotopic tracer experiments with ¹³C- and ¹⁴C-labelled compounds. The sequence of intermediates involved in the biosynthesis of the acetogenin moiety of (1) and (2) was assessed by incorporation of ¹⁴C-labelled precursors. The use of doubly-labelled ¹³C-acetate and ¹³C n.m.r. spectroscopy made it possible to determine the rest of the pathway as follows: prenylation of the acetogenin-derived aromatic nucleus, decarboxylation and hydroxylation in the same position, and finally cyclization of the terpenoid moiety. Details of the cyclization process were obtained by the use of ¹⁸O₂ and mass spectrometry.