Taxol, an organic molecule with 11 chiral centers, is a chemotherapy drug that has been successful in treating cancers characterized by solid tumors including breast, ovarian, lung, and prostate. It is categorized as a plant alkaloid, a chemotherapy drug synthesized from plants. Plant alkaloids include a variety of antimicrotubule agents like Taxol. Antimicrotubule agents prohibit the activity of the microtubules which are required for cell division. The mechanism of prohibition of the microtubules is not yet fully understood. The chirality of this molecule speaks to its specificity in pathway interruption of the microtubules. Taxol only confers the desired effects in a specific arrangement: 7-S chiral centers and 4-R chiral centers. Taxanes are produced by the bark of the Pacific Yew tree. Stripping bark from the Pacific yew trees kills them, but it has been discovered that taxol can be made from a compound gathered from the needles of the common English yew tree. See the pictures below for the structure and stereochemistry of this natural product.