ABSTRACT
Extracts from the root bark of Calotropis gigantea were subjected to bioactivity-guided fractionation using growth inhibitory effects against Entamoeba histolytica. The n-hexane soluble portion of the chloroform extract showed in vitro antiamoebic activity against the HK-9 strain of Entamoeba histolytica. Chromatographic separation of the chloroform extract afforded the known compound, procesterol, which showed activity against E. histolytica.
Subject(s)
Calotropis/chemistry , Entamoeba histolytica/drug effects , Plant Extracts/chemistry , Plant Extracts/pharmacology , Steroids/pharmacology , Animals , Antiprotozoal Agents/chemistry , Antiprotozoal Agents/pharmacology , Molecular Structure , Plant Bark/chemistry , Plant Roots/chemistry , Steroids/chemistryABSTRACT
The novel analogues of 5-nitrofuran-2-carboxaldehyde thiosemicarbazones 1-10 were synthesized and their copper(II) 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 1H 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 Entamoeba 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 microM of 2a and IC50 = 0.34 microM of 9a versus IC50 = 1.81 microM of metronidazole). These results indicate that the metallated thiosemicarbazone may be lead molecule to inhibit growth of E. histolytica.
Subject(s)
Antiprotozoal Agents/chemical synthesis , Antiprotozoal Agents/pharmacology , Copper/chemistry , Entamoeba histolytica/drug effects , Nitrofurans/chemistry , Nitrofurans/pharmacology , Thiosemicarbazones/chemistry , Thiosemicarbazones/pharmacology , Animals , Antiprotozoal Agents/chemistry , Entamoeba histolytica/growth & development , Humans , Inhibitory Concentration 50 , Magnetic Resonance Spectroscopy , Molecular Structure , Nitrofurans/chemical synthesis , Organometallic Compounds/chemical synthesis , Organometallic Compounds/chemistry , Organometallic Compounds/pharmacology , Spectrophotometry, Infrared , Thiosemicarbazones/chemical synthesisABSTRACT
Synthesis of new Palladium(II) and Ruthenium(II) complexes of the type, [Pd(L)Cl(2)] and [Ru(eta(4)-C(8)H(12))(L)Cl(2)] [where, L = thiosemicarbazones derived from 5-nitrothiophene-2-carboxaldehyde and cycloalkylaminothiocarbonyl hydrazines] have been isolated by the reaction of [Pd(DMSO)(2)Cl(2)] and [Ru(eta(4)-C(8)H(12))(CH(3)CN)(2)Cl(2)] with 5-nitrothiophene-2-carboxaldehyde thiosemicarbazones. The spectral data revealed that the thiosemicarbazones act as bidentate ligands, making use of thionic sulphur and the azomethine nitrogen atom for coordination to the central metal ion. Microdilution method was used for the assessment of antiamoebic activity of all the compounds against HK-9 strain of Entamoeba histolytica. Among all the thiosemicarbazones, 5-NT-4-BPTSCN (3) showed significant antiamoebic activity (IC(50) - 2.56 microM). Enhancement of antiamoebic activity resulted by introducing palladium and ruthenium metals in the thiosemicarbazone moiety. All the Pd(II) and Ru(II) complexes of 5-nitrothiophene-2-carboxaldehyde thiosemicarbazones were found more active then their respective ligands. The complexes 1a-4a, 1b and 3b showed antiamoebic activity.
Subject(s)
Amebicides , Organometallic Compounds , Palladium/chemistry , Ruthenium/chemistry , Thiosemicarbazones , Amebicides/chemical synthesis , Amebicides/chemistry , Amebicides/pharmacology , Animals , Entamoeba histolytica/drug effects , Inhibitory Concentration 50 , Molecular Structure , Organometallic Compounds/chemical synthesis , Organometallic Compounds/chemistry , Organometallic Compounds/pharmacology , Parasitic Sensitivity Tests , Spectrum Analysis/methods , Thiosemicarbazones/chemical synthesis , Thiosemicarbazones/chemistry , Thiosemicarbazones/pharmacologyABSTRACT
Thiosemicarbazones (1-7) and their palladium(II) complexes (1a-7a) of the type [Pd(TSCN)Cl(2)] (where TSCN=thiosemicarbazone) were prepared from 5-nitro thiophene-2-carboxaldehyde and [Pd(DMSO)(2)Cl(2)], respectively. Coordination via the thionic sulphur and the azomethine nitrogen atom of the thiosemicarbazones to the metal ion were confirmed by spectral data. These compounds were screened in vitro against (HK-9) strain of Entamoeba histolytica possess amoebicidal properties. Enhancement of antiamoebic activity resulted due to the introduction of palladium metal in the thiosemicarbazone moiety. The most promising of the group tested are [Pd(5-N-2-TCA-COTSCN)Cl(2)] and [Pd(5-N-2-TCA-AdmTSCN)Cl(2)] comparable to that of metronidazole.
Subject(s)
Amebicides/chemical synthesis , Organometallic Compounds/chemical synthesis , Palladium/chemistry , Thiosemicarbazones/chemical synthesis , Amebicides/pharmacology , Animals , Entamoeba histolytica/drug effects , Inhibitory Concentration 50 , Organometallic Compounds/pharmacology , Spectrum Analysis , Structure-Activity Relationship , Thiosemicarbazones/pharmacologyABSTRACT
In view of the antiamoebic properties observed for many thiophene-2-carboxaldehyde thiosemicarbazones, a series of N(4)-substituted thiosemicarbazones metal complexes derived from thiophene-2-carboxaldehyde was prepared for evaluation against Entamoeba histolytica. Reaction of thiophene-2-carboxaldehyde with cycloalkylaminothiocarbonylhydrazines having different amines gave the corresponding thiosemicarbazones. Reaction of latter with [Pd(DMSO)(2)Cl(2)] gave requisite palladium thiosemicarbazone complexes of the type [Pd(TSC)Cl(2)] (where TSC=thiosemicarbazones). Screening of antiamoebic activity of these compounds was assayed in vitro against (HM-1:1MSS) strain of E. histolytica. Enhancement of antiamoebic resulted from introducing palladium metal in the thiosemicarbazone moiety. Among the studied compounds, [Pd(2-TCA-1,2,3,4-THQTSC)Cl(2)] (2a) showed better activity.
Subject(s)
Amebicides/chemical synthesis , Palladium , Thiosemicarbazones/chemical synthesis , Amebicides/chemistry , Amebicides/pharmacology , Animals , Drug Evaluation, Preclinical , Entamoeba histolytica/drug effects , Inhibitory Concentration 50 , Organometallic Compounds/chemical synthesis , Organometallic Compounds/chemistry , Organometallic Compounds/pharmacology , Spectrum Analysis , Structure-Activity Relationship , Thiosemicarbazones/chemistry , Thiosemicarbazones/pharmacologyABSTRACT
Several thiosemicarbazone derivatives of 5-nitrothiophene-2-carboxaldehyde were prepared by the simple process in which N(4)-thiosemicarbazone moiety was replaced by aliphatic, arylic and cyclic amine. Among these thiosemicarbazones compound 11 showed significant antiamoebic activity whereas compound 3 was more active antitrichomonal than the reference drug.
Subject(s)
Aldehydes/chemistry , Antiprotozoal Agents/chemical synthesis , Antiprotozoal Agents/pharmacology , Sulfhydryl Compounds/chemistry , Thiosemicarbazones/chemistry , Thiosemicarbazones/pharmacology , Aldehydes/pharmacology , Amines/chemistry , Animals , Entamoeba histolytica/drug effects , Giardia lamblia/drug effects , Inhibitory Concentration 50 , Parasitic Sensitivity Tests , Structure-Activity Relationship , Sulfhydryl Compounds/pharmacology , Trichomonas vaginalis/drug effectsABSTRACT
Reaction of [MoO(2)(acac)(2)] (where, acac=acetyl acetone) and KVO(3) with 2-(salicylidieneimine) benzimidazole lead to form new complexes [MoO(2)(sal-BMZ)(2)] and K [VO(2)(sal-BMZ)(2)] [where, sal-BMZ=2-(salicylidieneimine) benzimidazole], which showed the monobasic bidentate nature of the ligand in which the phenolic oxygen and the imine nitrogen of the ligand are coordinated to the metal ion. These complexes were characterized along with nine other complexes of oxoperoxovanadium (V), molybdenum (Vl) and tungsten (Vl) with benzimidazole derivatives and screened in vitro by micro dilution technique for their amoebicidal activity with a view to search for a more effective agent against Entamoeba histolytica suggests that compound 2 and 3 might be endowed with important antiamoebic properties since they showed IC(50 )values in a microM range.
