Pseudomonic acid. Part 2. Biosynthesis of pseudomonic acid A

Abstract

The biosynthetic precursors of pseudomonic acid A (la) have been defined by using radioisotopically labelled substrates. Positions of labelled atoms and values of ¹J_CC couplings in (la) biosynthesised from [1-¹³C]-, [2-¹³C]-, and [1,2-¹³C₂]-acetate, [1-¹³C]- and [3-¹³C]-propionate, and L-[Me-¹³C]methionine have been determined by ¹³C n.m.r. spectroscopy. A biosynthetic route to (la) is suggested which proceeds through C₁₂,C₉, and C₅ units.