Vinca rosea

Vinca rosea plants Benzene Sulfuric acid... 

According to U.S. Patent 3,225,030, 1,500 grams of dried ground plant of Vinca rosea were Intimately mixed with 1,000 ml of a 2% tartaric acid solution, and the mixture was extracted with three 9-liter portions of benzene. The benzene extracts were combined and were concentrated in vacuo to about 1,500 ml. The concentrate was mixed with 1 liter of 2% tartaric acid and the mixture was steam-distilled under reduced pressure until all of the benzene had distilled over. The insoluble residue was dissolved in hot methanol, a second 1-liter portion of 2% tartaric acid solution was added, and the mixture was steam-distilled under reduced pressure until all of the methanol had distilled. 

The alkaloid mixture from the extraction of Vinca rosea plants (as in vinblastine extraction) was chromatographed to give vincristine which was then converted to the sulfate, according to U.S. Patent 3,205,220. 

Vinca alkaloids (vincristine, vinblastine, vindesine) are derived from the periwinkle plant (Vinca rosea), they bind to tubulin and inhibit its polymerization into microtubules and spindle formation, thus producing metaphase arrest. They are cell cycle specific and interfere also with other cellular activities that involve microtubules, such as leukocyte phagocytosis, chemotaxis, and axonal transport in neurons. Vincristine is mainly neurotoxic and mildly hematotoxic, vinblastine is myelosuppressive with veiy low neurotoxicity whereas vindesine has both, moderate myelotoxicity and neurotoxicity. 

Fig. 12.10 Enantioselective formation of neolignans in Vinca rosea and Piper regnellii...

A crude enzyme preparation from Vinca rosea catalyzed the enantioselective coupling of coniferyl alcohol to give rise to an optically active C8-C5 neolignan, dehydrodiconiferyl alcohol, with a ratio of (—)-enantiomer to (+)-enantiomer of 2 1 (Fig. 12.10) [66],... 

The discovery of medicinal alkaloids from Catharanthus roseus G. Don (Vinca rosea L.) represents one of the most important introductions of plant products into the cancer chemotherapeutic armamentarium. The relatively unique effects and toxicities of these agents have allowed the design of multiagent chemotherapy programs that have demonstrated sufficient effectiveness to achieve cures even of advanced tumors in many instances. This great accomplishment is possible only because of the inclusion of many different drugs, including the binary Vinca alkaloids. 

The correct botanical name of this pantropical flowering plant is Catharanthus roseus G. Don. A commonly used name is Vinca rosea L. 

The discovery of vinblastine and vincristine is one of the most intriguing examples of serendipity in scientihc research in recent years. In 1952, the Canadian medical researcher Robert Laing Noble (1910-90) received a package from his brother. Dr. Clark Noble, containing 25 leaves from the Madagascar periwinkle plant. Vinca rosea. Clark had received the leaves from one of his patients in Jamaica, who said that natives on the island often used the plant to control their diabetes when insulin was not available. Clark, who was retired, suggested that his brother study the plant for possible use as a drug for the treatment of diabetes. 

The contractile proteins of the spindle apparatus must draw apart the replicated chromosomes before the cell can divide. This process is prevented by the so-called spindle poisons (see also colchicine, p. 316) that arrest mitosis at metaphase by disrupting the assembly of microtubules into spindle threads. The vinca alkaloids, vincristine and vinblastine (from the periwinkle plant. Vinca rosea) exert such a cell-cycle-specific effect. Damage to the nervous system is a predicted adverse effect arising from injury to microtubule-operated axonal transport mechanisms. 

Vinblastine (4) and vincristine (5) are closely related indole-dihydroindole dimers (bisindole alkaloids), isolated from Catharanthus roseus (L.) G. Don (formerly known as Vinca rosea L.), the Madagascar periwinkle. Both of these anticancer agents, known as vinca alkaloids in the medical literature, are specific binders of tubulin, leading to tubulin depolymerization and cell cycle arrest in the metaphase stage. 

Other examples of natural drugs may be pointed out streptozotocin (from streptomyces achromogenes), bleomycin (from streptomyces verticillus), adriamy-cin and daunomycin (from streptomyces pencetius), mitomycin C (from streptomyces caesipitosus), vincristine, vinblastine and vindoline (from catharanthus roseus or vinca rosea L.). 

Vinblastine and vincristine are alkaloids isolated from plants of the periwinkle family (Vinca rosea). These compounds cause cells to stop at metaphase and inhibit assembly of microtubules, and likewise, failure of mitotic spindle formations. They inhibit synthesis of nucleic acids and proteins. 

The vinca alkaloids are isolated from plant Vinca rosea. They are cell cycle specific and mitotic inhibitors. 

Nature has been a potential source of therapeutic agents for thousands of years. An impressive number of modem dmgs have been derived from natural sources. Over the last century, a number of top selling dmgs have been developed from natural products. Anticancer dmg vincristine from Vinca rosea, narcotic analgesic morphine from Papaver somniferum, antimalarial dmg artemisinin from Artemisia annua, anticancer dmg Taxol from Taxus brevifolia and antibiotic peniciUins from Penicillium ssp. are just a few examples. 

Vinblastine is an alkaloid derived from the periwinkle plant Vinca rosea. Its mechanism of action involves inhibition of tubulin polymerization, which disrupts assembly of microtubules, an important part of the cytoskeleton and the mitotic spindle. This inhibitory effect results in mitotic arrest in metaphase, bringing cell division to a halt, which then leads to cell death. Vinblastine and other vinca alkaloids are metabolized by the liver P450 system, and the majority of the drug is excreted in feces via the biliary system. As such, dose modification is required in the setting of liver dysfunction. The main adverse effects are outlined in Table 54-4, and they include nausea and vomiting, bone marrow suppression, and alopecia. This agent is also a potent vesicant, and care must be taken in its administration. It has clinical activity in the treatment of Hodgkin s... 

Vincristine is an alkaloid derivative of Vinca rosea and is closely related in structure to vinblastine. Its mechanism of action, mechanism of resistance, and clinical pharmacology are identical to those of vinblastine. Despite these similarities to vinblastine, vincristine has a strikingly different spectrum of clinical activity and safety profile. 

The Madagascar periwinkle Catharanthus roseus (= Vinca rosea) (Apocynaceae) is a small herb or shrub originating in Madagascar, but now common in the tropics and widely cultivated as an ornamental for its shiny dark green leaves and pleasant five-lobed flowers. Drug material is now cultivated in many parts of the world, including the USA, Europe, India, Australia, and South America. 

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