Novel tubulysin derivatives which may be useful as cytotoxic agents to provide therapeutic benefits in the treatment of various types of cancers, alone, as drug conjugates or in combination with other chemotherapies are provided.本發明提供新穎妥布賴森衍生物,其可單獨、作為藥物結合物或與其他化學療法組合適用作細胞毒性劑以在治療多個類型之癌症中提供治療益處。