Dimerization of catharanthine and vindoline

[1] The localization of catharanthine and vindoline within the plant tissue has been heavily studied in recent years with conflicting results.

The dimerization of catharanthine and vindoline to form vinblastine and vincristine is catalyzed by a peroxidase and a reductase, and includes several intermediate compounds.

[3] C. roseus are poisonous but medically useful plants due to the various terpenoid indole alkaloids (TIAs) they produce in their leaves, roots, and flowers.

[2] In 1996-1998, three studies headed by Mariana Sottomayor from the University of Porto, Portugal localized catharanthine and vindoline in the vacuoles of the plant's cells.

[2] It has been theorized that the dimerization of catharanthine and vindoline is limited by multiple factors, two being the availability of hydrogen peroxide and the localization of the TIAs.

These studies show that some level of cellular separation between the alkaloids limits their ability to interact and react to produce vinblastine and vincristine.