Fig. 9. 800 MHz 1H NMR spectra of VCR sulphate in D2O:CD3CN 1:1 (top), in DMSO-d6 (middle) and in CDCl3 (bottom).
Fig. 10. Part of the 800 MHz 1H NMR spectra of VLB (top) and a VLB analogue (bottom) in DMSO-d6 (25 ◦C).
Fig. 11. Part of 800 MHz 1H NMR spectrum of VCR in CDCl3 (25 ◦C).
Fig. 12. Conformation of the vindoline half (left), the nine membered ring (middle) and the velbanamine half (right) of VLB as determined by Hunter et al. [81].
Fig. 13. Tube representation of the molecular structure of the vindoline half (left)
and the velbanamine half (right) of VLB reproduced from the X-ray structure [82].
Fig. 14. GHSQCAD (upper left), 15N-GHMBCAD (lower left) spectra of VLB measured in ACN-D2O solvent mixture and the 13C 15N-GHMBC spectrum (right) derived from
these data using unsymmetrical indirect covariance NMR processing.