Detection of 1,2-hydride shifts in the formation of euph-7-ene by the squalene–tetrahymanol cyclase of Tetrahymena pyriformis

Incubation of samples of 2,3-dihydrosqualene, specifically labeled with deuterium at either carbon position 7 or 11, with an enzyme extract from Tetrahymena pyriformis, containing a squalene–tetrahymanol cyclase, provided specimens of euph-7-enes displaying deuterium patterns consistent with the biosynthetic operation of two consecutive 1,2-hydride shifts.