Absolute configurations of tubulin inhibitors taltobulin (HTI-286) and HTI-042 characterized by X-ray diffraction analysis and NMR studies.

Abstract The stereochemistry of the tubulin inhibitors taltobulin HTI-286 ( 2 ) and HTI-042 ( 3 ) was determined by utilizing the DPFGSE 1D NOE experiment. Single crystal X-ray diffraction analysis further confirmed the absolute configuration of these two compounds, which carry the ( S , S , S )-configuration necessary for biological activity.