Stereochemical and NMR computatioal study of some natural dimeric bisindole alkaloids

The initial conformational search followed by the optimization of geometric parameters and high-level calculation of 1 H and 13 C NMR chemical shifts were carried out for 12 bisindole alkaloids of the Corynanthe-Strychnos series. Configurational assignments of all compounds from this series were performed based on the correlation of calculated and experimental NMR chemical shifts. for some alkaloids , the reassignment of the individual resonances together with spectral assignments of experimentally unresolved signals were suggested.