Novel C2–C3′ N-peptide linked macrocyclic taxoids. Part 2: Synthesis and biological activities of docetaxel analogues with a peptide side chain at C2 and their macrocyclic derivatives

The synthesis of a series of novel docetaxel analogues possessing a peptide side chain at the C2 position as well as peptide macrocyclic taxoids is described. These compounds were designed to mimic a region of the α-tubulin loop equivalent to the paclitaxel binding pocket of β-tubulin. Fifteen new peptide taxoids were obtained and evaluated as inhibitors of microtubule disassembly as well as cell proliferation. The relationships between these new taxoids and the tau protein motif interacting with microtubules are discussed.