Solid-phase total synthesis of cyclic decapeptide phakellistatin 12

Pakellistatin 12 (1) is a new cancer cell growth inhibitory (P388 ED50 2.8 mu g/mL) cyclodecapeptide that was isolated from a marine sponge Phakellia sp. The first total synthesis of compound I is reported here using solid-phase methodology with safety-catch linker strategy. For the sequence of amino acids in the cycle, the peptide product was analyzed with a MALDI TOF/TOF instrument, and the structure of the synthetic product was found to be chemically and spectroscopically identical to the natural substance.