The biosynthesis of murayaquinone, a rearranged polyketide

Incorporations of sodium [1,2-C-13(2)]acetate and sodium [1-C-13,O-18(2)]acetate confirmed that murayaquinone, produced by Streptomyces murayamaensis, is a polyketide. However, the labeling patterns revealed that a simple folding of the decaketide intermediate does not lead directly to the final phenanthrene skeleton. Instead a different phenanthrene is apparently formed that undergoes an oxidative cleavage, isomerization, and re-closure to a new phenanthrene skeleton. (C) 1997 Elsevier Science Ltd.