Periwinkle Alkaloids II: Vincristine

During the past 2 decades, vincristine (vcr), an alkaloid obtained from the plant Vinca rosea Linn, has been one of the most frequently used chemotherapeutic agents because of its wide spectrum of antitumor activity and its lack of myelosuppression.1 Although its mechanisms of action may be multiple, the major effect appears to be related to its high affinity binding to the basic protein subunit of microtubules, tubulin, which results in disruption of the mitotic spindle apparatus and arrest of cells in metaphase.1