Docetaxel chemical structure

Fig. 1. Chemical structure of the taxanes. The chemical structures of docetaxel and paclitaxel. From ref. 5.

FIGURE 62.1 Chemical structures of paclitaxel (taxol) and its more potent analog, docetaxel (taxotere). 

Fig. 4. Anticancer drugs paclitaxel and docetaxel. Both compounds can be obtained by chemical structure modification of baccatin III or 10-deacetyl baccatin III...

Docetaxel differs from paclitaxel at two positions in its chemical structure. It has a hydroxyl functional group on C-10 (see Fig. 101.1) whereas paclitaxel has an acetate ester, and a tert-butyl carbamate ester exists on the phenylpropionate side chain instead of the benzyl amide in paclitaxel. The C-10 functional group change causes docetaxel to be more water soluble than paclitaxel. 

The use of 19F NMR for a variable temperature (VT) NMR study of fluorinated taxoids is obviously advantageous over the use of H NMR because of the wide dispersion of the l9F chemical shifts that allows fast dynamic processes to be frozen out. Accordingly, F2-paclitaxel 65 and F-docetaxel 66 were selected as probes for the study of the solution structures and dynamic behavior of paclitaxel and docetaxel, respectively, in protic and aprotic solvent systems.77 The inactive 2, 10-diacetyldocetaxel (73) was also prepared to investigate the role of the 2 -hydroxyl moiety in the conformational dynamics.89 While molecular modeling and NMR analyses (at room temperature) of 73 indicate that there is no significant conformational changes as compared to paclitaxel, the 19F NMR VT study clearly indicates that this modification exerts marked effects on the dynamic behavior of the molecule.77... 

Ojima, I., Kuduk, S. D., Chakravarty, S., et al. (1997) A novel approach to the study of solution structures and dynamic behavior of paclitaxel and docetaxel using fluorine-containing analogs as probes. Journal of the American Chemical Society, 119, 5519-5527. 

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