Synthesis and evaluation of anti-Toxoplasma gondii and antimicrobial activities of thiosemicarbazides, 4-thiazolidinones and 1,3,4-thiadiazoles

Abstract In this work we reported the synthesis and evaluation of anti- Toxoplasma gondii and antimicrobial activities in vitro of three new compound series obtained from ethyl(5-methyl-1- H -imidazole-4-carboxylate): acylthiosemicarbazide analogues 3a – d , 4-thiazolidinone analogues 4a – d and 1,3,4-thiadiazole analogues 5a – d . All synthesized compounds were characterized by IR, 1 H, 13 C NMR and HRMS. The majority of the tested compounds show excellent anti- T. gondii activity when compared to hydroxyurea and sulfadiazine. In addition it was also shown that most of the compounds in this study have a better performance against intracellular tachyzoites. The results for antimicrobial activity evaluation showed weak antibacterial and antifungal activities for all the tested molecules, when compared with the standard drugs (chloramphenicol and rifampicin for antibacterial activity; nistatin and ketoconazole for antifungal activity).