Question

The common weed Catharanthus roseus (=Vinca rosea) is a source of
(a) Hay fever
(b) Two carcinogens-vincristine and vinblastine
(c) Two anti-cancer drugs- vincristine and vinblastine
(d) Skin rashes

Answer 1

Hint: It is indole alkaloids. These alkaloids are known to bind to the microtubules of the spindle apparatus. They are active agents and they also affect DNA synthesis and amino acid metabolism. They also are known to reduce mitosis at metaphase.

Complete answer:
Vinca rosea is a native and endemic ornamental and medicinal plant. C. roseus is a native weed to Madagascar, where it is now endangered due to habitat destruction. The genus Catharanthus is firmly identified with the class Vinca and the species C. roseus was earlier called Vinca rosea. This species is the main source of vinca alkaloids, now sometimes called Catharanthus alkaloids. The plant produces about 130 of these compounds, including vinblastine and vincristine, two drugs that are used to treat cancer.

Additional Information: The genus Catharanthus which comprises 8 species, and all are originating from Madagascar except for the species Catharanthus pusillus, which is restricted to India and Sri LankaPerennial subshrub, woody at base, up to 1 m tall, generally with white latex and an unpleasant smell; roots up to 70 cm long; stems narrowly winged, green or red, shortly hairy to glabrous, often woody at the base.
In the wild endangered species is a quickly developing plant that is easy to develop. It is developed in the nurseries and parks worldwide and it has additionally escaped away from cultivation and naturalized close to houses, in disturbed sites, and in normal environments in occasionally dry and moist habitats. The species produces more small seeds that can be easily dispersed by ants, wind, and water.
So, the correct answer is ‘Two anti-cancer drugs- vincristine and vinblastine’.

Note: The risk of the introduction of C. roseus is very high. Because this species has been widely introduced as ornamental and because it spreads by the seeds and cuttings, there is a high probability for this species to escape from cultivation and it becomes naturalized into natural areas, principally in areas near cultivation.