The<unk> s are diterpenes produced by the plants of the genus Taxus (yews).  As their name suggests, they were first derived from natural sources, but some have been synthesized artificially.<unk> s include paclitaxel and docetaxel. Paclitaxel was originally derived from the Pacific yew tree.<unk> s have been used to produce various chemotherapy drugs. The principal mechanism of the<unk>  class of drugs is the disruption of microtubule function.  It does this by stabilizing GDP-bound tubulin in the microtubule. Microtubules are essential to cell division, and<unk> s therefore stop this - a "frozen mitosis".  Thus,<unk> s are essentially mitotic inhibitors.  In contrast to the<unk> s, the vinca alkaloids destroy mitotic spindles. Both,<unk> s and vinca alkaloids are therefore named spindle poisons or mitosis poisons, but they act in different ways.<unk> s are also thought to be radiosensitizing.
Taxane
Zorubicin
Paclitaxel
Epirubicin
Estramustine
Epirubicin hydrochloride
Amrubicin
Pirarubicin