The structure of ervinceine
UV spectrum: Xma x (ethanol) 248, 328 m/l (log ~ 4.12, 4.26), which is characteristic for a -methylene indol ine alkaloids. The NMR spectrum of ervinceine with signals at 8 8, 88 (NH, singlet), 6 .14-6 .91 (aromatic protons, 3H), [ 3.69 (singlet, COOCHs), 3.66 (singlet, OCHs), and 0.58 (triplet, --C--C~Hs). I The reduction of ervinceine with zinc in methanoiic sulfuric acid gave dihydroervinceine, C2zHz0NzOz, mp 118:119" C (methanol), [a]~3 +3.3 (c 0.9; chloroform). Its IR spectrum; Xrnax (ethanol) 249, 305 mg (log ~ 3.78, 3.73) is characteristic of ind0tine bases. Its mass spectrum has the molecular peak M + 370 (16%) and also peaks of ions with m/e 339 (M--OCH~) + I0%, 2~4 (M--86) + 26% and 124 (I00%).
Alkaloids from Vinca herbacea W.K. X. The structures and stereochemistry of majdine and isomajdine.
Abstract The alkaloids A-5 or A-4 first obtained from Vinca herbacea W.K. are identical with the alkaloids majdine, later isolated from Vinca major L. and with its isomer isomajdine. The spectral and chemical evidence, leading to the structural elucidation of theses two bases , is presented so that majdine can be represented by I and isomajdine II.
Die Struktur des Herbalins — eines Oxindol-Alkaloids aus Vinca herbacea W. K.†
Aus der Pflanze Vinca herbacea W. K. isolierten wir das Alkaloid Herbalin (5) als ersten Vertreter einer Oxindol-heteroyohimban-Gruppe mit hydrierter Δ16.17-Doppelbindung.