New Indole Alkaloids from Amsonia sinensis

Abstract

Fourteen indole alkaloids, Δ¹⁴-isoeburnamine (1), amsosinine (2), tabersonine, vincadifformine, lochnericine, tetrahydroalstonine, β-yohimbine, isoeburnamine, minovicinine, picrinine, strictamine, rhazimine, vincanidine, and decarbomethoxytetrahydrosecamine, were isolated from Amsonia sinensis. Δ¹⁴-isoeburnamine (1) and amsosinine (2) are new compounds, their structures have been established by spectral and chemical methods. A known sterol glycoside, daucosterol, has also been obtained. The structures of compounds 1 and 2 were finally confirmed by X-ray diffraction of single crystals.

Key words

Amsonia sinensis - Apocynaceae - indole alkaloids - Δ¹⁴-isoeburnamine - amsosinine