Biosynthesis of (+)-cubenene and (+)-epicubenol by cell-free extracts of cultured cells of Heteroscyphus planus and cyclization of [2H]farnesyl diphosphates

Abstract

The absolute stereochemistry of cubenene and epicubenol from cultured cells of Heteroscyphus planus was determined as both (+)-isomers by ¹H and ¹³C NMR spectroscopy, GLC using a chiral capillary column, and optical rotations. Incubation of two geometrical isomers of deuteriated farnesyl diphosphate (FPP) with a cell-free extract from cultured cells indicated that both compounds were specifically formed from (2E,6E)-FPP. Gas–liquid chromatography–mass spectrometry (GLC–MS) and ²H NMR analyses of (+)-cubenene and (+)-epicubenol generated from [1,1-²H₂]- and [6-²H]-FPP confirmed the presence of 1,2- and 1,3-hydride shifts in their formation.