RESUMO
A series of N'-substituted-2-(5-nitrofuran or 5-nitrothiophen-2-yl)-3H-benzo[d]imidazole-5-carbohydrazide derivatives were synthesized and investigated for their abilities to inhibit ß-hematin formation, hemoglobin hydrolysis and in vivo for their antimalarial efficacy in rodent Plasmodium berghei. Selected analogues were screened for their antitubercular activity against sensitive MTB H(37)Rv and multidrug-resistant MDR-MTB strains, and cytotoxic activity against a panel of human tumor cell lines and two nontumourogenic cell lines. Compounds 3a, 5a, f, 6g were the most promising as inhibitors of ß-hematin formation, however, their effect as inhibitors of hemoglobin hydrolysis were marginal. The most active compounds to emerge from the in vitro and in vivo murine studies were 3a and 6i, suggesting an antimalarial activity via inhibition of ß-hematin formation and are as efficient as chloroquine. The cytotoxic and antitubercular activities of the present compounds were not comparable with those of the standard drugs employed. But, however, compound 5b showed better antitubercular activity compared to rifampin against multidrug-resistant MDR-MTB strains. Compounds 3a, 6i and 5b showed a good safety index.
Assuntos
Antimaláricos/síntese química , Antituberculosos/síntese química , Benzimidazóis/química , Hidrazinas/química , Animais , Antimaláricos/química , Antimaláricos/toxicidade , Antituberculosos/química , Antituberculosos/toxicidade , Linhagem Celular Tumoral , Resistência a Múltiplos Medicamentos , Hemina/antagonistas & inibidores , Hemina/metabolismo , Hemoglobinas/metabolismo , Humanos , Hidrazinas/síntese química , Hidrazinas/toxicidade , Hidrólise , Camundongos , Plasmodium/efeitos dos fármacosRESUMO
A series of phenylsubstituted pyrazolo and pyrimido benzothiazine dioxide derivatives were synthesized and investigated for their abilities to inhibit beta-hematin formation, hemoglobin hydrolysis and in vivo for their antimalarial efficacy in rodent Plasmodium berghei. Compounds 3-amino-7-chloro-9-(2'-methylphenyl)-1,9-dihydro-pyrazolo-[4,3-b]benzothiazine 4,4-dioxide 2b and 2,4-diamino-8-chloro-10H-phenyl-pyrimido-[5,4-b]benzothiazine 5,5-dioxide 3a were the most promising as inhibitors of hemoglobin hydrolysis, however, their effect as inhibitors of beta-hematin formation was marginal, except for compound 3-amino-7-chloro-9-(3'-chlorophenyl)-1,9dihydro-pyrazolo-[4,3-b]benzothiazine 4,4-dioxide 2g. The most active compound to emerge from the in vitro and in vivo murine studies was 2b, suggesting an antimalarial activity via inhibition of hemoglobin hydrolysis, however, not as efficient as chloroquine.
Assuntos
Antimaláricos/síntese química , Antimaláricos/farmacologia , Plasmodium berghei/efeitos dos fármacos , Tiazinas/síntese química , Tiazinas/farmacologia , Animais , Antimaláricos/química , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Espectrofotometria Infravermelho , Tiazinas/químicaRESUMO
An improved procedure for the synthesis of 3-amino-9-arylsubstituted-thieno[3,2-b]benzothiazine S,S-dioxide 2-decarboxylated is reported. Thieno-[3,2-b]benzothiazine S,S-dioxide derivatives were investigated for their abilities to inhibit beta-hematin formation, hemoglobin hydrolysis and in vivo for their efficacy in rodent Plasmodium berghei. Compounds 5j-o were the most promising as inhibitors of hemoglobin hydrolysis, however, the compounds are not as efficient as chloroquine. A structure-activity relationship (SAR) study was carried out in this series. Our results allow us to determine the minimal structural requirements to produce the biological response.