Fehmida Naqvi

Studies on a newly developed linseed oil-based alumina-filled polyesteramide anticorrosive coating

Polyesteramide (PEA) and alumina-filled polyesteramide (APEA) resins were synthesized from N,N′-bis(2 hydroxyethyl) linseed amide. The FTIR, 1H-NMR, DSC, TGA, thermal curing, and physico-chemical characterization of these polymers were carried out. The coatings of PEA and APEA were made on mild steel strips. The mechanical behavior and protective efficiency of these coatings in acid, alkali, and organic solvents were investigated. APEA coatings have been found to show superior performance in comparison to other coatings.

Synthesis and in vitro antiprotozoal activity of 5-nitrothiophene-2-carboxaldehyde thiosemicarbazone derivatives

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.

New palladium(II) complexes of 5-nitrothiophene-2-carboxaldehyde thiosemicarbazones: synthesis, spectral studies and In vitro anti-Amoebic activity

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.

Synthesis and antiamoebic activity of new cyclooctadiene ruthenium(II) complexes with 2-acetylpyridine and benzimidazole derivatives.

Reaction of [Ru(eta4-C8H12) (CH3CN)2 Cl2] with 2-(2-pyridyl) benzimidazole or Schiff bases derived from 2-acetylpyridine and S-methyldithiocarbazate, S-benzyldithiocarbazate and thiosemicarbazide leads to form new complexes of the type [Ru(eta4-C8H12)(L)Cl2] (where L=ligand). In vitro, most of the compounds exhibited potent activity and the Ru derivatives 1a [Ru(eta4-C8H12)(2-Acpy-SMDT)Cl2], 2a [Ru(eta4-C8H12)(2-Acpy-SBDT)Cl2] and 3a [Ru(eta4-CsH12)(2-Acpy-TSC)Cl2] were found more active than metronidazole against (HK-9) strain of Entamoeba histolytica.

Synthesis, characterization and antiamoebic activity of benzimidazole derivatives and their vanadium and molybdenum complexes.

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.

Synthesis, spectral studies and screening for amoebicidal activity of new palladium(II) complexes derived from thiophene-2-carboxaldehyde thiosemicarbazones

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.

Synthesis, characterisation and antiamoebic activity of new thiophene-2-carboxaldehyde thiosemicarbazone derivatives and Their cyclooctadiene Ru(II) complexes

Reaction of new thiosemicarbazones (1-4) derived from thiophene-2-carboxaldehyde and cycloalkylaminothiocarbonylhydrazine with [Ru(eta(4)-C8H12)(CH3CN)2Cl2] leads to form complexes (1a-4a) of the type [Ru(eta(4)-C8H12)(TSC)Cl2] (where TSC=thiosemicarbazone). All the compounds have been characterised by elemental analysis, IR, 1H NMR, electronic spectra and thermogravimetric analysis. It is concluded that the thionic sulphur and the azomethine nitrogen atom of the ligands are bonded to the metal ion. In vitro antiamoebic screening against (HK-9) strain of Entamoeba histolytica indicated that the Ru(II) complexes of thiophene-2-carboxaldehyde thiosemicarbazones were found more active than the thiosemicarbazones.

Synthesis, crystal structure, and enhancement of the efficacy of metronidazole against Entamoeba histolytica by complexation with palladium(II), platinum(II), or copper(II)

Reaction of trans-[PdCl2(DMSO)(2)]. cis-[PtCl2(DMSO)(2)]. and [Cu(OAc)(2)](H2O)-H-. with metronidazole (mnz) leads to the formation of new complexes, i.e., trans-[PdCl2(mnz)(2)] (1), trans-[PtCl2(mnz)(2)] (2). and trans-[Cu-2(OAc)(4)(mnz)(2)] (3), respectively. Complexes 1-3 crystallize all in the centrosymmetric monoclinic space group P2(1)/c with Z = 8. Unit-cell parameters for these complexes are: 1, a = 7.1328(14) Angstrom, b = 20.699(4) Angstrom, c = 7.1455(14) Angstrom, and beta = 116.17(3)degrees; 2, a = 9.9169(14) Angstrom, b = 21.853(4) Angstrom, c = 6.7218(13) Angstrom, and beta = 110.79(3)degrees: 3. a = 9.1663(18) Angstrom, b = 19.129(4) Angstrom, c = 8.9446(18) Angstrom, and beta = 116.44(3)degrees. The complexes 1 and 2 maintain an ideal square-planar geometry. In complex 3, the H2O molecules of the starting complex are replaced by metronidazole while maintaining a dimeric structure of [Cu(OAc)(2)]. Each Cu ion has an ideal octahedral structure, though distortion occurs in the equatorial position where the acetato ligands are attached. The Cu-Cu separation of 2.6343(8) Angstrom indicates considerable metal-metal interaction. The testing of the antiamoebic activity of these complexes against the protozoan parasite Entamoeba histolytica suggests that compound 1-3 might be endowed with important antiamoebic properties since they showed IC50 values in a muM range better than metronidazole (Table 2). Thus, compound 1 displayed more effective amoebicidal activity than metronidazole (IC50 values of 0.103 muM vs. 1.50 muM resp.).

Alumina‐Incorporated Polyesteramide from Non‐Edible Seed Oils

To improve the physico‐mechanical and chemical resistance properties, lower the curing temperature of annona squamosa and pongamia glabra seeds oils based polyesteramides [ASPEA, PGPEA], as well as to convert the non‐edible seed oils into value added products, their respective alumina‐incorporated polyesteramides resins [Al‐ASPEA, Al‐PGPEA] have been synthesized. The resins and their coatings have been tested for their chemical, physico mechanical and chemical/corrosion resistance properties. These properties were compared among the prepared resins and with that of previously reported alumina filled linseed polyesteramide [Al‐LPEA]. It was observed that Al‐PGPEA‐71, which has the highest amount of oleic acid chains, shows the best physico‐mechanical and chemical resistance properties.

Synthesis, characterization, and screening for antiamoebic activity of Palladium(II), Platinum(II), and Ruthenium(II) complexes with NS-donor ligands

Reaction of [PdCl2(DMSO)2], [PtCl2(DMSO)2], and [RuCl2(η4-C8H12)(MeCN)2] with S-acetyl Nβ-acetyldithiocarbazate (=2-acetylhydrazinecarbodithioic acid anhydrosulfide with ethanethioic acid; aadt; 1), S-methyl Nβ-[(5-nitrothiophene-2-yl)methylene]dithiocarbazate (=S-methyl 2-[(5-nitrothiophene-2-yl)methylene]hydrazinecarbodithioate; mntdt; 2), and S-benzyl Nβ-[(5-nitrothiophene-2-yl)methylene]dithiocarbazate (=S-benzyl 2-[(5-nitrothiophene-2-yl)methylene]hydrazinecarbodithioate; bntdt; 3) led to new complexes [PdCl2(L)], [PtCl2(L)], and [RuCl2(η4-C8H12)(L)] (L=ligands 1–3). All these compounds were characterized by elemental analysis, IR, 1H- and 13C-NMR and UV/VIS spectra and thermogravimetric analysis. Ligand 1 coordinates through the thioxo S-atom and the carbazate N(β) atom, whereas in ligands 2 and 3 the thioxo S-atom and the azomethine N-atom are coordinated to the metal ion. Screening of antiamoebic activity of these compounds was performed in vitro against the HK-9 strain of E. histolytica. All the complexes were more active than their respective ligands; compound 3a showed the most promising activity.