Studies in terpenoid biosynthesis. Part XV. Biosynthesis of the sesquiterpenoid illudin M

Abstract

The labelling pattern has been determined for the sesquiterpenoid illudin M, biosynthesized by Clitocybe illudens from [2-³H,2-¹⁴C]-, [(2R)-2-³H,2-¹⁴C]-, [(2S)-2-³H,2-¹⁴C]-, [(4R)-4-³H,2-¹⁴C]-, [5-³H,2-¹⁴C]-, and [(5R)-5-³H,2-¹⁴C]-mevalonic acids. Results from [5-³H]mevalonate and [1-³H]farnesyl pyrophosphate suggest that a hydride shift from C-9 to C-1 occurs; the results from [2-³H]mevalonate suggest that a hydrogen atom is lost from C-4 of farnesyl pyrophosphate during the cyclization sequence.