Synthesis of Triazenoazaindoles: a New Class of Triazenes with Antitumor Activity

Despite improvements in the treatment and prevention of cancer, the number of new diagnoses continues to rise; this has fuelled substantial interest in the development of new and effective chemotherapeutic agents. Compounds of the triazene class, such as dacarbazine, have been used in the clinical managementof many cancer types including brain, leukemia, and melanoma. A new compound class bearing a triazenoazaindolescaffold was synthesized with the aim of identifying new antiproliferativeagents. Compounds 5a–g and 6a–c werescreened against a panel of human tumor cell lines, and two of them, 5e and 5 f, showed cytotoxicity (GI50 range: 2.2–8.2 mm) in all cell lines. These two compounds even maintained their cytotoxicity in some multidrug-resistant cell lines. Flow cytometry analysis demonstrated their ability to induce cell death by apoptosis with involvement of lysosomes.