Synthesis and Biological Evaluation of Novel 2-Aroyl Benzofuran-Based Hydroxamic Acids as Antimicrotubule Agents.

Because of synergism between tubulin and HDAC inhibitors, we used the pharmacophore fusion strategy to generate potential tubulin-HDAC dual inhibitors. Drug design was based on the introduction of a -hydroxyacrylamide or a -hydroxypropiolamide at the 5-position of the 2-aroylbenzo[]furan skeleton, to produce compounds - and -, respectively. Among the synthesized compounds, derivatives , , , , and showed excellent antiproliferative activity, with IC values at single- or double-digit nanomolar levels, against the A549, HT-29, and MCF-7 cells resistant towards the control compound combretastatin A-4 (CA-4). Compounds and were also 10-fold more active than CA-4 against the Hela cell line. When comparing the inhibition of tubulin polymerization versus the HDAC6 inhibitory activity, we found that -, , , , and , although very potent as inhibitors of tubulin assembly, did not have significant inhibitory activity against HDAC6.