Zinc ions were shown by polarography to coordinate strongly to vinblastine and to vindoline. A calcium or magnesium ion excess liberated these alkaloids from their zinc complexes. The calcium ion coordination of vinblastine was investigated with a calcium ion-selective electrode. The complex formation processes proved to be pH-independent in the pH range 3.5-5.0. The experimental results, together with others on analogous vincristine-containing systems, indicate that the metal ions are coordinated to non-protonating oxygen donor atoms on the vindoline moiety of vincristine or vinblastine.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry