Synthesis and biological evaluation of pyrazolylnaphthoquinones as new potential antiprotozoal and cytotoxic agents.
The importance of American trypanosomiasis (Chagas' disease) in human pathology is widely known. The prognosis of this disease is poor and the choice of effective medicines limited, thus study of new drugs is absolutely necessary. In this work, the activities of three new pyrazolylnaphthoquinones, heterocyclic naphthoquinones bearing 3-aminopyrazole rings, were evaluated on Trypanosoma cruzi, the etiological agent of Chagas' disease. These activities were compared with those of three 5-aminoisoxazole analogues. In addition, since these compounds belong to a family of antiprotozoal and cytotoxic/antitumor agents, the activities of all six against Plasmodium falciparum, Trypanosoma brucei rhodesiense, and murine L-6 cells were also investigated. In the biological tests, five of the compounds showed significant in vitro trypanocidal activities against T. cruzi, with activities similar to that of benznidazole. Two of the 5-aminoisoxazole analogues also showed good activities, in one case highly selective, against the K1 and NF54 strains of P. falciparum (IC(50)<0.12 microg mL(-1)). Three of the compounds were cytotoxic to murine L-6 cells (IC(50)=0.21-0.50 microg mL(-1)). The results suggested that the three pyrazolylnaphthoquinones and one of the 5-aminoisoxazole analogues could be starting points for lead optimization programs against T. cruzi and P. falciparum, respectively.
Sperandeo
Norma R
NR
Departamento de Farmacia, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba 5000-Córdoba, Argentina. nrscor@dqo.fcq.unc.edu.ar
Brun
Reto
R
D000818:Animals; D000962:Antimalarials / Q000138:chemical synthesis / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000494:pharmacology*; D000981:Antiprotozoal Agents / Q000138:chemical synthesis* / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D051379:Mice; D032446:Myoblasts / Q000187:drug effects; D009285:Naphthoquinones / Q000138:chemical synthesis* / Q000494:pharmacology*; D010963:Plasmodium falciparum / Q000187:drug effects; D051381:Rats; D014344:Trypanocidal Agents / Q000138:chemical synthesis / Q000494:pharmacology; D016833:Trypanosoma brucei rhodesiense / Q000187:drug effects; D014407:Tumor Cells, Cultured
D000962:Antimalarials; D000970:Antineoplastic Agents; D000981:Antiprotozoal Agents; D007202:Indicators and Reagents; D009285:Naphthoquinones; D014344:Trypanocidal Agents