Cyclic peptides are structurally diverse molecules exhibiting a broad spectrum of biological functions with inherent physiological advantages, ranging from insecticidal and antimicrobial to anti-inflammatory and immunosuppressing activities. The synthesis and study of cyclic peptide analogues thus presents a powerful advance in the design and discovery of novel peptide drugs. During the past 20 years, phakellistatins 1-18 have been isolated as prolin-rich cyclic peptides with potent activities against various cancer cell lines. The solid-phase total syntheses of two members of the series,...