Carbonic anhydrase inhibitors: metal complexes of a sulfanilamide derived Schiff base and their interaction with isozymes I, II and IV

Metal complexes of aromatic/heterocyclic sulfonamides act as stronger inhibitors of the zinc enzyme carbonic anhydrase (CA, EC 4.2.1.1) as compared to the uncomplexed sulfonamides from which they are derived. Here we report the synthesis and inhibition studies against the physiologically relevant isozymes CA I, CA II and CA IV, of a series of metal complexes (Co(II), Ni(II) and Cu(II) derivatives) of a Schiff-base ligand, obtained from sulfanilamide and salicylaldehyde. The best activity was observed for the Cu(II) and Co(II) complexes, against CA II and CA IV, for which inhibition constants in the range of 15-39 and 72-108nM, respectively, were seen. The enhanced efficacy in inhibiting the enzyme may be due to a dual mechanism of action of the metal complexes, which interact with CA both by means of the sulfonamide moieties as well as the metal ions present in their molecule.

Antibacterial cobalt(II) and zinc(II) complexes of pyrazine-derived NNO and NNN donor Schiff-bases

A series of biologically active pyrazine-derived Schiff-base ligands have been synthesized by the condensation reaction of 2-aminopyrazine with salicylaldehyde and acetamidobenzylaldehyde. Then their cobalt(II), nickel(II) and zinc (II) complexes have been prepared. The biological evaluation of the simple uncomplexed ligand in comparison to their complexed compounds have been determined against bacterial strains e.g., Escherichia coil, Staphylococcus aureous and Pseudomonas aeruginosa.

Synthesis, spectroscopic and biological studies of some mono- and di-substituted hydrazine-derived ferrocenes

Some mono-and disubstituted hydrazine-derived ferrocenes have been synthesized and studied for their antibacterial properties. All these synthesized compounds have been characterized by their physical, analytical and spectral data, which introduces a novel class of ferrocene compounds. The antibacterial properties, of these compounds have also been evaluated and thus a significant use of such compounds as antibacterial agent is reported.

Biological role of anions (sulfate, nitrate, oxalate and acetate) on the pharmacological properties of cobalt(II) and nickel(II) chelates with thienoyl- and furenoyl-derived compounds

Biologically active complexes of cobalt (II) and nickel (II) with thienoyl- and furenoyl-derived Schiff-base ligands having the same metal ion but different anions such as sulfate, nitrate, oxalate and acetate have been prepared and characterized. In order to evaluate the role of anions on their pharmacological properties the synthesized complexes have been screened against bacterial species, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa and results have been reported.

Effect of cobalt (ii), copper (ii), nickel (ii) and zinc(ii) metal ions on the biological activity of triazine derived ligand

A new Schiff-base triazine-derived ligand and its cobalt (II), copper (II), nickel (II) and zinc (II) metal complexes have been synthesised and characterised on the basis of elemental analysis, molar conductance, infrared, HNMR and electronic spectral, and magnetic susceptibility data. In order to asssess the effect of metal ions on the antibacterial activity, the ligand and its complexes have been screened against bacterial species Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. In all cases the activity/potency has substantially increased on complexation against one or more bacterial species.

Synthesis, structural and biological studies of nickel(II), copper(II) and zinc(II) chelates with tridentate Schiff bases having NNO and NNS donor systems

New tridentate pyrimidine-derived NNO and NNS donor Schiff base ligands and their nickel(II), copper(II) and zinc(II) chelates have been synthesized and characterized on the basis of elemental analysis, 1H-NMR, IR and electronic spectral data and conductance and magnetic measurements. The synthesized ligands and their metal chelates have been screened and compared for their antibacterial action against bacterial species Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae.

Studies of the effect of anions (chloride, sulphate, nitrate, oxalate and acetate) on the pharmacological properties ofcobalt (ii) complexes with dithiooxamide-derived antibacterial agents

A number of cobalt (II) complexes with dithiooramide derived antibacterial agents having different anions i.e., chloride, sulphate, nitrate, oxalate and acetate have been synthesised, and the effect of anions on antibacterial properties of these complexes against bacterial species Staphylococcus aureus, Streptococcus pneumoniae and Escherichia coli has been determined.

Biologically active complexes of nickel(II), copper(II) and zinc(II) with Schiff-base ligand derived from the reaction of 2-aminopyridine and pyrrol-2-carboxaldehyde--their synthesis and characterisation

A new Schiff-base ligand N-(2'-pyrrylmethylidene)2-aminopyrimidine derived from the reaction of 2-amino pyrimidine and pyrrol-2-carboxaldehyde and its nickel(II), copper(II) and zinc(II) complexes have been synthesised and characterised on the basis of elemental analysis, molar conductance, infrared, electronic and proton nuclear magnetic resonance (1H-NMR) and magnetic susceptibility data. The ligand and its complexes when screened for antibacterial activity against bacterial species such as, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae. In all cases, the activity substantially increased on complexation with metals.

Studies on biologically active complexes of cobalt(II) and nickel(II) with dithiooxamide-derived ligands

A number of cobalt(II) and nickel(II) complexes with novel dithiooxamide ligands derived from precursors such as benzonitrile, benzosulfonamide, benzaldehyde, benzoic acid, and phenol have been synthesized and characterized on the basis of their elemental analysis molar conductance, magnetic moment, H NMR and electronic and IR spectral data. These ligands and their complexes have been screened for their antibacterial activities against bacterial species Staphylococcus aureus, Streptococcus pneumoniae, Escherichia coli, and Tuberculi bacilli. The studies indicate that in comparison to the ligands their metal complexes are more potent and antibacterial.

Synthesis of cobalt(II) and nickel(II) complexes of Ceclor (cefaclor) and preliminary experiments on their antibacterial character

Cobalt(II) and nickel(II) complexes of the antibacterial drug Ceclor have been synthesized and characterized on the basis of their elemental analysis, molar conductance, magnetic moment and electronic and infrared spectral data. These complex have been, then subjected to screening for their antibacterial properties against bacterial species such as Streptococcus pyogenes, Streptococcus pneumoniae, Staphylococcus aureus and Escherichia coli. In comparison to uncomplexed Ceclor, the metal complexes have been shown to be more antibacterial.