Design, Synthesis, and Cytotoxic Activity of New Tubulysin Analogues

Abstract

AbstractSynthesis of tubulysin analogues, containing an N-methyl substituent on tubuvaline-amide together with the replacement of either the hydrophobic N-terminal N-methyl pipecolic acid (Mep) or at both N- and C- terminal peptides with available heteroaromatic acids and an unsaturated tubuphenylalanine moiety, respectively, were described. The in vitro cytotoxic activity by SRB assay on five cancer cell lines for sixteen tubulysins was evaluated. Among them, five analogues exhibited strong cytotoxic activities against five human cancer cell lines, including human breast carcinoma (MCF7), human colorectal adenocarcinoma (HT-29), HL-60, SW-480, human lung adenocarcinoma (A459). Interestingly, one analogue showed the strongest cytotoxicity on all five tested cell lines even much higher toxicity than the reference compound ellipticine.