Søren Damtoft, S. Jensen, B. Nielsen
1992
Citations
0
Influential Citations
11
Citations
Journal
Phytochemistry
Abstract
Abstract Deuterium-labelled samples of 8-epi-iridodial, 8-epi-iridotrial and their glucosides were fed to Hebenstretia dentata. The aglucones were better precursors than their glucosides of ipolamiide and lamiide, the iridoid glucosides of the plant. A feeding experiment with 13C-labelled 10-hydroxy-geraniol showed that C-3 and C-11 are equivalent during biosynthesis of the iridoid glucosides and, thus, glucosidation must take place after formation of 8-epi-iridotrial. Isolation of the minor metabolites after feeding with 8-epi-deoxyloganic acid suggested that the route from this compound proceeds by oxidation at C-8 followed by esterification and that oxidation at C-5 is the final step.