Pharmacognosy of Vinca Alkaloids (Periwinkle)

Introduction:

Vinca alkaloids are obtained mainly from a species of periwinkle known as Madagascar Periwinkle. It is also known as “Sadabahar” or “Sadaphuli”. Other species of periwinkle are also known to contain vinca alkaloids. There are at least 150 alkaloids known to be extracted from Vinca. Vinca alkaloids are chemically indole alkaloids and are known to possess anti-cancer, anti-hypertensive and anti-diabetic roles.

Vinca Alkaloids / Madagascar Periwinkle

Biological Source Aerial parts of Catharanthus roseus formerly known as Vinca rosea.
Family Apocynaceae
Geographical Source Endemic to Madagascar and India.
Morphology/Macroscopical Characters A herbaceous subshrub, approximately 40-80 cm high. The leaves are oppositely arranged, oblong with petiolate acute base. The flowers are produced throughout the year, and are salveform, simple, generally 2-7 cm broad with usually 5 petals joined together at the base to form a tubule. The fruit is a divergent follicle.
Microscopic Characters -
Chemistry Vinca is rich in indole alkaloids  particularly vincristine and vinblastine. Coupling of indole alkaloids such as catharanthine and vindoline produces the vinca alkaloids. Other alkaloids such as ajmalicine, lochnerine and serpentine are also found.

Indole containing vinca alkaloids - Vinblastine, vincristine and vindoline.

Indole containing vinca alkaloids - Vinblastine, vincristine and vindoline.

Chemical Tests Answers all general tests for alkaloids
Adulterants/Allied drugs/ Substitutes Other Catharanthus species such as C. longifolius, C. trichophyllus and C. lanceus are known to contain vindoline type alkaloids.
Uses Vinca is useful in the herbal treatment of lymphomas. Vinblastine is used for the treatment of Hodgkin’s disease and non-Hodgkin’s lymphomas while vincristine is used principally in the treatment of acute lymphocytic leukaemia.
Other Notes (life cycle, extraction etc.) -

References:

  1. Evans, W. C. Trease and Evans Pharmacognosy, 16th ed.; Elsevier: New York, 2009.
  2. Kokate, C. K.; Gokhale, S. B.; Purohit, A. P. A textbook of Pharmacognosy, 29th ed.; Nirali Prakashan: Pune, 2009.
  3. Image taken from: Kuboyama, T. et. al. Stereocontrolled total synthesis of (+)-vincristine. PNAS, 2004, 101, 11966-11970.

About Akul Mehta