What part of Taxus brevifolia is used to produce paclitaxel?

The correct choice is the bark of Taxus brevifolia, commonly known as the Pacific yew. This species is particularly significant in the field of medicine because its bark contains the compound paclitaxel, which is a powerful chemotherapeutic agent used in the treatment of various cancers such as ovarian and breast cancer.

Paclitaxel is notable for its mechanism of action, which involves stabilizing the structure of microtubules and thus disrupting the normal process of cell division. The extraction of paclitaxel from the bark of the Pacific yew was a groundbreaking discovery in the late 20th century, leading to new treatments that have significantly improved patient outcomes.

This knowledge emphasizes the importance of certain plant parts in herbal and pharmaceutical preparations, where specific compounds are concentrated and utilized, highlighting the need for conservation and sustainable harvesting of such valuable resources.