Catharanthine

Catharanthine

Catharanthine is a monoterpenoid indole alkaloid (MIA) of the terpenoid indole alkaloid family. It is a key branch-point intermediate in the biosynthesis of the vinca alkaloids, particularly the clinically important antineoplastic alkaloids vinblastine and vincristine. In the plant, catharanthine is produced mainly in aerial tissues and can be transported to leaf epidermal cells, where it participates in the pathway leading to vindoline and, ultimately, the condensation product anhydrovinblastine.

Plants containing catharanthine

• Madagascar periwinkle (Catharanthus roseus; formerly Vinca rosea) — the principal and best-characterized natural source. Catharanthine occurs with other indole alkaloids, including vindoline, ajmalicine, serpentine, and tabersonine. The plant is the commercial starting material for semi-synthetic vinblastine and vincristine production.
• Other species of Catharanthus — related species may contain catharanthine or closely related MIAs, although their alkaloid profiles and concentrations vary and are much less documented than those of C. roseus.
• Some other Apocynaceae — catharanthine and related MIA compounds have been reported sporadically in additional members of the dogbane family, but reports are species-specific and should not be generalized to the entire family.

Important distinction: Common periwinkle (Vinca minor) is also an Apocynaceae plant and contains indole alkaloids, notably vincamine; it should not automatically be listed as a confirmed significant source of catharanthine without species- and tissue-specific analytical evidence.

Therapeutic significance

Catharanthine itself is primarily important as a biosynthetic precursor and research compound, rather than as a routinely used medicine. Its importance comes from its role in the pathway that produces vinca alkaloids, which interfere with microtubule dynamics and are used in chemotherapy.

Safety

Catharanthus roseus is toxic. Plant material and isolated alkaloids should not be used therapeutically without qualified medical supervision. Concentrations vary with plant part, cultivar, developmental stage, and growing conditions.

Related thoughts

• Monoterpenoid Indole Alkaloids
• Madagascar Periwinkle
• Vinca (genus)

Sources for further reading:

• Biosynthesis and regulation of terpenoid indole alkaloids in *Catharanthus roseus*
• USDA Dr. Duke’s Phytochemical and Ethnobotanical Databases — *Catharanthus roseus*