3β-Hydroxy-5β-cholest-7-en-6-one as an intermediate of 20-hydroxyecdysone biosynthesis in a hairy root culture of Ajuga reptans var. atropurpurea

Abstract
[3α-2H]-, [4α-2H]- and [4β-2H]-Cholesterols and [3α-2H]- and [5-2H]-3β-hydroxy-5β-cholest-7-en-6-ones were converted with a hairy root culture of Ajuga reptans var. atropurpurea into 20-hydroxyecdysone, in which the deuterium atoms retained their original positions, thus strongly suggesting that 3β-hydroxy-5β-cholest-7-en-6-one is an obligatory intermediate in the biosynthesis of ecdysteroids in the plant.