Stereochemistry of reduction of the 24,25-double bond in the biosynthesis of tigogenin in Digitalis lanata
Abstract
In tigogenin [(25R)-5α-spirostan-3β-ol] biosynthesized in Digitalis lanata a 4-pro-R-proton of mevalonic acid occupies the 24-pro-S-position, which indicates that reduction of Δ24-biosynthetic intermediates occurs with trans-stereochemistry.