Tetracyclic triterpenoids from Euphorbia nicaeensis All

In this study, three tetracyclic triterpenes: (3S,24S)-tirucall-7-ene-3,24,25-triol (1), (3S,24R)-tirucall-7-ene-3,24,25-triol (2) and inoterpene C (3), were isolated from the milkweed Euphorbia nicaeensis All. using dry-column flash silica gel chromatography and semipreparative normal-phase HPLC. Their structures were determined on the basis of 1D and 2D NMR spectra and literature review. Although these three compounds have previously been isolated from other plant species, this is the first time that they have been isolated from E. nicaeensis.