Synthesis and antiamoebic activity of 3,7-dimethyl-pyrazolo[3,4-e][1,2,4] triazin-4-yl thiosemicarbazide derivatives
摘要:
A series of 3,7-dimethyl-pyrazolo[3,4-e] [ 1,2,4]triazin-4-yl thiosemicarbazide derivatives 3-22 were prepared and evaluated in vitro against HMI:IMSS strain of Entamoeba histolytica, to identify the compounds for antiamoebic activity. They exhibited antiamoebic activity in the range (IC50 = 0.81-7.31 mu M). The results were compared to the activity of known drug metronidazole. It is inferred from the in vitro studies that the compounds 10, 11. 17 and 18 were found to be significantly better inhibitors of E. histolytica since IC50 values in the mu M range elicited by these compounds are much lower than metronidazole. Besides, compounds 11 and 17 have shown the most promising antiamoebic activity (IC50 = 0.81 mu M of 11, IC50 = 0.84 mu M of 17 versus IC50 = 1.81 mu M of metronidazole). The study suggests the possibility of developing triazine analogues as potential drug candidates for antiamoebic activity. (c) 2005 Elsevier B.V. All rights reserved.
Novel bidentate complexes of Cu(II) derived from 5-nitrofuran-2-carboxaldehyde thiosemicarbazones with antiamoebic activity against E. histolytica
作者:Sangita Sharma、Fareeda Athar、Mannar R. Maurya、Fehmida Naqvi、Amir Azam
DOI:10.1016/j.ejmech.2005.01.003
日期:2005.6
The novel analogues of 5-nitrofuran-2-carboxaldehyde thiosernicarbazones 1-10 were synthesized and their copper(H) complexes 1a-10a were obtained by means of coordination with cupric chloride. All these compounds have been characterized by elemental analysis, IR, electronic spectra and thermogravimetric patterns while ligands have also been characterized by H-1 NMR spectral studies. These copper complexes are bidentate and possess octahedral geometry around Cu(II) ion. Their antiamoebic activities were carried out to ascertain their effectiveness in comparison to their corresponding thiosemicarbazones. A number of these complexes possess noteworthy potencies towards HK-9 strain of Entainoeba histolytica in vitro. The complexes 2a-7a, 9a and 10a showed less IC50 value than metronidazole, the drug of choice for amoebiasis. Moreover, complexes 2a and 9a have shown the most promising antiamoebic activities (IC50 = 0.38 mu M of 2a and IC50 = 0.34 mu M of 9a versus IC50 = 1.81 mu M of metronidazole). These results indicate that the metallated thiosemicarbazone may be lead molecule to inhibit growth of E. histolytica. (c) 2005 Elsevier SAS. All rights reserved.
Cyclooctadiene Ru(II) complexes of thiophene-2-carboxaldehyde-derived thiosemicarbazones: synthesis, characterization and antiamoebic activity
作者:Shailendra Singh、Fareeda Athar、Mannar R. Maurya、Amir Azam
DOI:10.1016/j.ejmech.2006.01.014
日期:2006.5
Thiosemicarbazones (TSC) 1-10 were synthesized by condensing substituted thiosemicarbazide with thiophene-2-carboxaldehyde. These thiosemicarbazones were further reacted with [Ru(eta(4)-C8H12)(CH3CN)(2)Cl-2] to forrn complexes of the type [Ru(eta(4) -C8H12)(TSC)Cl-2] 1a-10a. Thiosemicarbazones exhibited antiamoebic activity in the range IC50 = 1.09-5.42 mu M. In vitro assessment of antiamoebic activity indicated that the thiosemicarbazones 3, IC50 = 1.67 mu M, 4, IC50 = 1.11 mu M and 6, IC50 = 1-09 mu M showed substantially less IC50 value than metronidazole (IC50 = 1.87 mu M), a commonly used drug against amoebiasis. Cyclooctadiene Ru(II) complexes of thiosemicarbazones showed significant improvement in antiamoebic activity (IC50 = 0.30-1.39 mu M). All the complexes possess noteworthy potencies and showed less IC50 values than metronidazole against HK-9 strain of Entamoeba histolytica. Among all the complexes, the most promising antiamoebic activities was shown by the complexes 4a and 6a (IC50 = 0.31 mu M of 4a and IC50 = 0.30 mu M of 6a versus metronidazole). (c) 2006 Elsevier SAS. All rights reserved.