Biosynthesis of 20-hydroxyecdysone in Ajuga hairy roots: fate of 6α- and 6β-hydrogens of lathosterol Original Research Article

The fate of 6α- and 6β-hydrogens of lathosterol during the transformation into 20-hydroxyecdysone was chased by feeding [3α,6β-2H2]- and [3α,6α-2H2]-lathosterols to hairy roots of Ajuga reptans var. atropurpurea. The behavior of 6β-hydrogen, which mostly migrated to the C-5 position of 20-hydroxyecdysone, was in agreement with that of C-6 hydrogen of cholesterol. The results strongly supported the view that cholesterol and lathosterol are first metabolized into 7-dehydrocholesterol, which is then converted into 20-hydroxyecdysone via 7-dehydrocholesterol 5α,6α-epoxide in the hairy roots.