Isolation, structural elucidation, and synthesis of tabernamine, a new cytotoxic bis-indole alkaloid from tabernamontana johnstonii

Studies on the total synthesis of bisindole alkaloids within the voacamine family

“…exhibited uv spectra similar to that of tabernamine (9) (4). Although the lH nmr spectra of these products were, as expected, more complex than those of the methoxy substituted compounds, their structures could be tentatively assigned on the basis of their aromatic proton signals.…”

“…The situation is less clear with indole units lacking such functionality, as would be required in the synthesis of 9 and 11. Although there are now a number of reported instances in which this type of reaction has been employed (4)(5)(6)(7)(10)(11)(12), the position of attachment of the 2-acylindole unit to the Iboga system has not in all cases been unequivocally established. It became necessary to provide a more detailed study of this reaction and to determine its general utility with various indole systems.…”

Nouveaux Alcaloides Indoliques Dimeres de Type Voacamine Extraits d'Ervatamia hainanensis

“…Les ervahanines appartiennent done á la serie des diméres de type vobasinyl-3 ibogane n'ayant pas de substituant méthoxyle sur la partie ibogane. A ce jour, seules la capuvosine (8,9) et la tabernamine (10) présentaient cette particularité dans cette série.…”

Plant Anticancer Agents V: New Bisindole Alkaloids from Tabernaemontana johnstonii Stem Bark

“…Tabernamine (VII1)-The major evidence for the structure of this new bisindole alkaloid was presented previously (11). It is of some importance, however, to assign unambiguously the position of attachment of the vobasane ring system to the ibogamine moiety.…”

“…The major fraction from this procedure was obtained as a white amorphous solid, homogeneous on TLC in two solvent systems and on HPLC, and was named tabernamine. The physical properties of tabernamine were described previously (11).…”