Taxol: A New Probe for Studying the Structure and Function of Microtubules

In 1971 Wall and his associates reported the isolation of taxol (Fig. 1) from the plant Taxus brevifolia. Its structure was elucidated, and its cytotoxicity against L1210, P388, and P1534 leukemia cells was documented (Wani et al, 1971; Wall and Wani 1977). When the National Cancer Institute began its evaluation of the antitumor activity and toxicity of taxol in experimental tumor systems, our laboratory initiated a study on the mechanism of action of this drug in tissue-culture systems and on in vitro microtubule assembly (Schiff et al, 1979). Our original interest in taxol was generated by its unique chemical structure: a taxane drivative with an oxetan ring. This ring system is rare in natural products, and its biological properties had not been previously studied (Della Casa de Marcano et al. 1975).