All of the following are true about paclitaxel except?

Ans. d. Obtained from E. coli Paclitaxel Alkaloid ester derived from the Western yew (Taxus brevifolia) and the European yew (Taxus baccata)Q. Mechanism of Action: Mitotic spindle poison through high-affinity binding to microtubules with enhancement of tubulin polymerization Binds to beta-tubulin and enhances its polymerization (a mechanism opposite to that of vinca alkaloids) Microtubules are stabilized and their depolymerization is prevented. Abnormal arrays or 'bundles' of microtubules are produced throughout the cell cycle Cytotoxic action of paclitaxel emphasizes the impoance of tubulin-microtubule dynamic equilibrium. Indications: Metastatic ovarian and breast carcinoma after failure of first-line chemotherapy and relapse cases. Wide variety of solid tumors,including ovarian, advanced breast, non-small cell and small cell lung, head and neck, esophageal, prostate, and bladder cancer AIDS-related Kaposi's sarcomaQ Side-Effects: Reversible myelosuppression, gastro intestinal mucositis and hair loss, stocking and glove neuropathyQ