443144-66-9Relevant articles and documents
Synthesis, characterization and antiamoebic activity of 1-(thiazolo[4,5-b]quinoxaline-2-yl)-3-phenyl-2-pyrazoline derivatives
Abid, Mohammad,Azam, Amir
, p. 2812 - 2816 (2007/10/03)
A new series of 1-N-thiocarboxamide-3-phenyl-2-pyrazolines 1-6 was synthesized by cyclization of different Mannich bases with unsubstituted thiosemicarbazide. The reaction of cyclized pyrazoline derivatives 1-6 with 2,3-dichloroquinoxaline afforded the title compounds 7-12. The structures of the new compounds were confirmed by elemental analyses as well as 1H, 13C NMR, IR and electronic spectral data. The HM1:IMSS strain of Entamoeba histolytica parasite was cultured in vitro and the sensitivity of the parasite to the synthesized compounds was evaluated using the microdilution method. Among all the pyrazoline derivatives 1-6, none was found to be a better inhibitor as compared to the reference drug, metronidazole. The quinoxaline derivatives, 9, 11 and 12 were found to be potent inhibitors of E. histolytica.
Synthesis and structure-activity relationship study of potent trypanocidal thio semicarbazone inhibitors of the trypanosomal cysteine protease cruzain
Du, Xiaohui,Guo, Chun,Hansell, Elizabeth,Doyle, Patricia S.,Caffrey, Conor R.,Holler, Tod P.,McKerrow, James H.,Cohen, Fred E.
, p. 2695 - 2707 (2007/10/03)
American trypanosomiasis, or Chagas' disease, is the leading cause of heart disease in Latin America. Currently there is an urgent need to develop antitrypanosomal therapy due to the toxicity of existing agents and emerging drug resistance. A novel series of potent thio semicarbazone small-molecule inhibitors of the Trypanosoma cruzi cysteine protease cruzain have been identified. Some of these inhibitors have been shown to be trypanocidal. We initially discovered that 3′-bromopropiophenone thio semicarbazone (1i) inhibited cruzain and could cure mammalian cell cultures infected with T. cruzi. 3′-Bromopropiophenone thio semicarbazone showed no toxicity for mammalian cells at concentrations that were trypanocidal. Following this lead, more than 100 compounds were designed and synthesized. A specific structure-activity relationship (SAR) was established, and many potent analogues with IC50 values in the low nanomolar range were identified. Eight additional analogues were trypanocidal in a cell culture assay, and this indicates that aryl thio semicarbazone is a productive scaffold for killing the parasites. Kinetic studies show that these are time-dependent inhibitors. Molecular modeling studies of the enzyme-inhibitor complex have led to a proposed mechanism of interaction as well as insight into the SAR of the thio semicarbazone series. The nonpeptide nature of this series, small size, and extremely low cost of production suggest this is a promising direction for the development of new antitrypanosome chemotherapy.
