Fluorescent and Other Labeled Taxols

The taxol analog 11.3.1 with a m-dimethylaminobenzoyl group on the side chain has been prepared by Georg and her collaborators and used to probe the interaction of taxol and tubulin (394), and the 

The three fluorescent analogs 11.3.12-11.3.14 were prepared and studied by Amat-Guerri and Andreu (400, 401) analogs 11.3.12 (Flutax-1) and 11.3.13 (Flutax-2) were found to be useful for the study of the microtubule cytoskeleton, as discussed later (section 15.2). 

The four fluorescent taxols 11.3.16-11.3.19 were prepared by Nicolaou and his colleagues 402), and 11.3.18 was found to be the most suitable derivative for optical microscopy studies of the cell. 

Similar analogs to those described above were prepared by Lai and coworkers 382). These investigators used a 7-(aminocaproyl) linker to couple lissamine rhodamine B (structure E above) or fluorescein isothiocyanate to taxol, and confirmed that both derivatives can be used to carry out intracellular fluorescence mapping. 

Two nitroxylated taxol analogs, 7-(4-carboxy-2,2,6,6-tetramethyl-l-piperidinyloxy)-taxol and the corresponding 2 -analog were prepared and used to obtain information about the orientation of taxol at its binding site on tubulin using EPR. It was concluded that taxol is strongly immobilized after polymerization of tubulin, but that it is not constrained in the dimer structure 403). 

---