Lys3]Didemnins as potential affinity ligands

The synthesis and biological activity of N(epsilon)-Z-Lys3]didemnin B are reported. This novel analogue retains antiproliferative, cytotoxic, and protein biosynthesis inhibition activities, but at reduced levels. This result suggests the use of Lys3]didemnin derivatives as potential affinity probes for studying the molecular target(s) of the didemnin class of natural products.