Paclitaxel is a monomer diterpenoid extracted from the bark of Natural Plant Taxus. It is a complex secondary metabolite. It is also the only drug known to promote microtubule polymerization and stabilize polymerized microtubules. Isotope tracing showed that paclitaxel was only bound to polymerized microtubules and did not react with unpolymerized tubulin dimers. After contacting paclitaxel, cells will accumulate a large number of microtubules in cells. The accumulation of these microtubules interferes with various functions of cells, especially stops cell division in the mitotic stage and blocks normal cell division.











