Which alkaloid is extracted from Camptotheca acuminata and has anti-cancer properties?

Camptothecin is the correct answer because it is specifically derived from the bark of the tree Camptotheca acuminata, commonly known as the happy tree. This alkaloid has been extensively studied and recognized for its potent anti-cancer properties, particularly its ability to inhibit the enzyme topoisomerase I, which plays a crucial role in DNA replication and cell division. By hindering this enzyme, camptothecin interferes with cancer cell proliferation, making it effective in treating various types of cancers.

In the context of other alkaloids mentioned, cocaine is a notable stimulant with different uses, primarily in the realm of anesthetics and recreational drugs; brucine has mostly been studied for its potential toxicity rather than therapeutic significance in cancer treatment, and reserpine is used primarily for its effects on blood pressure and as an antipsychotic. These distinctions highlight camptothecin's specific relevance and effectiveness in the fight against cancer, supported by its unique source and mechanism of action.