Abstract Despite rapid advances in both the early detection and treatment of cancer, the mortality from this disease remains high, which justifies the development of new products that are more selective and effective and have fewer side effects. Accordingly, a novel ester was synthesized that contains two pharmacophores with important biological activities: (I) 4-aminoantipyrine, which has anti-inflammatory and antioxidant effects, and (II) the pharmacophore 1,4-dioxo-butenyl, which has cytotoxic activity. When administered alone, this compound is non-genotoxic, and it does not cause an increasing in splenic phagocytosis. Nevertheless, it can induce cell death. When administered in combination with commercial chemotherapeutic agents, such as doxorubicin, cisplatin, and cyclophosphamide, the ester shows antigenotoxic activity and decreases phagocytosis and reduces the potential to cause cell death. These results indicate that the compound should not be used in combination with chemotherapeutic agents that exert their effect through DNA damage, an important feature of antitumor drugs.

Abstract Chemotherapy is one of the major approaches for the treatment of cancer. Therefore, the development of new chemotherapy drugs is an important aspect of medicinal chemistry. Chemotherapeutic agents include isocoumarins, which are privileged structures with potential antitumoral activity. Herein, a new 3-substituted isocoumarin was synthesized from 2-iodo-3,5-dimethoxy-benzoic acid and oct-1-yne in a cross-coupling Sonogashira reaction followed by a copper iodide-catalyzed intramolecular cyclization as key step using MeOH/Et3N as the solvent system. The present study also evaluated the leukometry, phagocytic activity, genotoxic potential and cell death induction of three different doses (5 mg/kg, 10 mg/kg and 20 mg/kg) of this newly synthesized isocoumarin, alone and in combination with the commercial chemotherapeutic agents cyclophosphamide (100 mg/kg) and cisplatin (6 mg/kg) in male Swiss mice. The results suggest that the isocoumarin has genotoxicity and causes cell death. Noteworthy, this new compound can increase splenic phagocytosis and lymphocyte frequency, which are related to immunomodulatory activity. When combined with either cyclophosphamide or cisplatin, chemopreventive activity led to a reduction in the effects of both chemotherapeutic drugs. Thus, the new isocoumarin is not a candidate for chemotherapeutic adjuvant in treatments using cyclophosphamide or cisplatin. Nevertheless, the compound itself is an important prototype for the development of new antitumor drugs.