Studies on argentine plants—XXXI

Alkaloids of Strychnos soubrensis

“…The minor alkaloids were identified as strychnofendlerine (figure 1) (5-8) and isosplendine (figure 1) (5,9,10) by means of spectral data by comparison (Rf, ir, uv, ms, 'H-nmr) with authentic samples. One of the major alkaloids proved, by spectral data and by comparison (Rf, 'H-nmr, ir, uv, ms) with an authentic sample, to be identical to strychnobrasiline (figure 2) (5,7,10,11). The second major alkaloid was not identical with any of the indole alkaloids recorded in the literature.…”

1H and 13C NMR spectra of Strychnos alkaloids: Selected NMR updates

“…All 1 H NMR data for this compound were reported in the early paper, [40] where the resonances of H-9 (7.02 ppm) and H-12 (6.73 ppm) should apparently be interchanged based on the calculated chemical shifts for H-9 (6.77 ppm) and H-12 (7.51 ppm). We also give our calculated value of the unreported proton chemical shift of the olefinic proton (5.94 ppm) and provide a number of individual methylenic proton shifts unresolved in the experimental spectrum.…”

“…No inconsistencies are found in the experimental 13 C NMR spectrum of 5 given in the basic paper, [39] while very scarce information is available on its 1 H NMR spectrum dealing with unassigned aromatic protons H-9, H-10, H-11, and H-12 providing complex unresolved multiplets. [40] Given below are the full set of proton chemical shifts of 5 calculated in the present study.…”

Les Alcaloïdes majoritaires duStrychnos scheffleridu Zaire

“…Na-acetylstrychnosplendine SM identique a celui de Ia Na-acétylisostrychnosplendine[26], UV[9,10], IR[10,27].3. Strychnobrasiline SM, UV, JR et RMN'H[6,11].Comparaison CCM avec un échantillon de réfé-UV, JR[22]. Comparaison CCM avec un échantiilon de référence.…”