(E)-4-[(2-carbamoylhydrazinylidene)methyl]-3-hydroxy-5-hydroxymethyl-2-methylpyridin-1-ium nitrate.

The title compound, C9H13N4O3(+)·NO3(-), is the first structurally characterized Schiff base derived from semicarbazide and pyridoxal. Unusually for an unsubstituted semicarbazone, the compound adopts a syn conformation, in which the carbonyl O atom is in a cis disposition relative to the azomethine N atom. This arrangement is supported by a pair of hydrogen bonds between the organic cation and the nitrate anion. The cation is essentially planar, with only a hydroxymethyl O atom deviating significantly from the mean plane of the remaining atoms (r.m.s. deviation of the remaining non-H atoms = 0.01 Å). The molecules are linked into flat layers by N-H···O and C-H···O hydrogen bonds. O-H···O hydrogen bonds involving the hydroxymethyl group as a donor interconnect the layers into a three-dimensional structure.

Bis{N,N,N-trimethyl-2-oxo-2-[2-(2,3,4- trihydroxy-benzyl-idene)hydrazin-yl]ethanaminium} tetra-chlorido-zincate(II) methanol solvate.

The asymmetric unit of the title compound, (C(12)H(18)N(3)O(4))(2)[ZnCl(4)]·CH(3)OH, consists of two Girard reagent-based cations, a tetra-chlorido-zincate anion and a mol-ecule of methanol as solvate. These components are inter-connected in the crystal structure by an extensive network of O-H⋯O, N-H⋯O, C-H⋯O, O-H⋯N, O-H⋯Cl, N-H⋯Cl and C-H⋯Cl hydrogen bonds. The shortest inter-molecular inter-action is realized between the cation and anion [H⋯Cl = 2.29 (5) Å; O-H⋯Cl = 167 (3)°]. C-H⋯O inter-actions also play a important role in the inter-connection of the cations.

Different intermolecular interactions in azido[2-(diphenylphosphino)benzaldehyde semicarbazonato-kappa2P,N1,O]nickel(II).

The title compound, [Ni(C(20)H(17)N(3)OP)(N(3))], is the first complex with a semicarbazide-based ligand having a P atom as one of the donors. The influence of the P atom on the deformation of the coordination geometry of the Ni(II) ion is evident but less expressed than in the cases of complexes with analogous seleno- and thiosemicarbazide ligands. The torsion angles involving the two bonds formed by the P atom within the six-membered chelate ring have the largest values [C-P-Ni-N = 24.3 (2) degrees and C-C-P-Ni = -24.2 (4) degrees ], suggesting that the P atom considerably influences the conformation of the ring. Two types of N-H...N hydrogen bond connect the complex units into chains.

{4-[(Carbamimidoylhydrazono)methyl-kappa2N1,N4]-5-hydroxymethyl-2-methylpyridinium-3-olate-kappaO}(methanol-kappaO)copper(II) dinitrate.

The title compound, [Cu(C(9)H(13)N(5)O(2))(CH(4)O)](NO(3))(2), consists of square-planar cationic complex units where the Cu(II) centre is coordinated by an N,N',O-tridentate pyridoxal-aminoguanidine Schiff base adduct and a methanol molecule. The tridentate ligand is a zwitterion exhibiting an almost planar conformation. The dihedral angles between the mean planes of the pyridoxal ring and the six- and five-membered chelate rings are all less than 2.0 degrees. The charge on the complex cation is neutralized by two nitrate counter-ions. Extensive N-H...O and C-H...O hydrogen bonding connects these ionic species and leads to the formation of layers. The pyridoxal hydroxy groups are the only fragments that deviate significantly from the flat layer structure; these groups are involved in O-H...O hydrogen bonding, connecting the layers into a three-dimensional crystal structure.

FT-IR and theoretical study of 3,5-dimethyl-1H-pyrazole-1-carboxamidine (L) and the complexes CoL2(H2O)2(NO3)2, NiL2(H2O)2(NO3)2.

In the paper a joint experimental and theoretical study of 3,5-dimethyl-1H-pyrazole-1-carboxamidine (L) as well as its complexes CoL2(H2O)2(NO3)2 and NiL2(H2O)2(NO3)2 is reported. On the basis of FT-IR experiments and a DFT-derived scaled quantum mechanical force field the normal coordinate analysis of L was carried out. The FT-IR spectra of the two complexes were interpreted using the present assignment of L and computed vibrational data of the complexes. The ionic and charge transfer interactions in the complexes were assessed by means of natural bond orbital (NBO) analysis.

Synthesis, spectroscopic and X-ray characterization of a copper(II) complex with the Schiff base derived from pyridoxal and aminoguanidine: NMR spectral studies of the ligand.

A copper(II) complex with the pyridoxal-aminoguanidine (PL-AG) Schiff base adduct, as an organic compound of the very potent biological activity and promising pharmacological importance in the treatment of diabetic complications, has been prepared and characterized. The X-ray structural analysis of the [CuCl2(PL-AG)] complex showed that it has a distorted pseudo-square-pyramidal (4+1) structure with the tridentate ONN Schiff base in the equatorial plane, with the Cu-O(1), Cu-N(1) and Cu-N(3) bond lengths of 1.917(2)A, 1.930(2)A and 1.984(2)A, respectively. The bond length of the equatorial Cu-Cl(1) is 2.279(1)A, while that of the apical Cu-Cl(2) is 2.792(1)A. Pyridoxal fragment is coordinated in its zwitterionic form. In addition to the X-ray structural analysis, the complex was characterized by IR spectrometric, conductometric and magnetic techniques, and the ligand itself by IR, 1H and 13C NMR spectra.

Mannich bases of 1,2,4-triazole-3-thione containing adamantane moiety: Synthesis, preliminary anticancer evaluation, and molecular modeling studies.

A series of 18 novel N-Mannich bases derived from 5-adamantyl-1,2,4-triazole-3-thione was synthesized and characterized using NMR spectroscopy and X-ray diffraction technique. All derivatives were evaluated for their anticancer potential against four human cancer cell lines. Several tested compounds exerted good cytotoxic activities on K562 and HL-60 cell lines, along with pronounced selectivity, showing lower cytotoxicity against normal fibroblasts MRC-5 compared to cancer cells. The effects of compounds 5b, 5e, and 5j on the cell cycle were investigated by flow cytometric analysis. It was found that these compounds cause the accumulation of cells in the subG1 and G1 phases of the cell cycle and induce caspase-dependent apoptosis, while the anti-angiogenic effects of 5b, 5e, and 5j have been confirmed in EA.hy926 cells using a tube formation assay. Further, the interaction of Bax protein with compound 5b was investigated by means of molecular modeling, applying the combined molecular docking/molecular dynamics approach.

Synthesis, characterization, cytotoxicity and antiangiogenic activity of copper(II) complexes with 1-adamantoyl hydrazone bearing pyridine rings.

Three novel copper complexes with tridentate N2O ligand di(2-pyridil) ketone 1-adamantoyl hydrazone (Addpy) of the formula [Cu(II)2Cu(I)2(Addpy)2Br2(µ-Br4)] (1), catena-poly[CuCl(µ-Addpy)(µ-Cl)CuCl2]n (2) and [Cu(Addpy)(NCS)2] (3) were synthesized. Complexes are characterized by X-ray crystallography, spectral (UV-Vis, FTIR), electrochemical (CV) analyses, and magnetochemical measurements. Investigation of anticancer potential of Cu(II) complexes, mode of cell death, apoptosis, and inhibition of angiogenesis were performed. All tested malignant cell lines (HeLa, LS174, A549, K562, and MDA-MB-231) showed high sensitivity to the examined Cu(II) complexes. It has been shown that the complexes induce apoptosis in the caspase 3-dependent manner, whereas the anti-angiogenic effects of 1, 2, and 3 have been confirmed in EA.hy926 cells using a tube formation assay.

Synthesis, characterization and antitumor activity of polymeric copper(II) complexes with thiosemicarbazones of 3-methyl-5-oxo-1-phenyl-3-pyrazolin-4-carboxaldehyde and 5-oxo-3-phenyl-3-pyrazolin-4-carboxaldehyde.

New polymeric copper(II) complexes with two tridentate ONS thiosemicarbazone ligands containing substituted pyrazolone moiety were synthesized and characterized by means of spectroscopic, electrochemical and crystallographic techniques. While both ligands exist as different tautomers in the solid state and DMSO-d(6) solution, Cu(II) ion coordinates the ligands from the same tautomeric form with square-pyramidal geometry around each Cu atom. In the crystal structures, the copper(II) complex cation forms polymeric chains {[Cu(L)Cl](+)}(n) with a bridging chlorine atom. One of the complexes was found to have a significantly higher cytotoxic potential in comparison with cisplatin in inhibition of several cell lines (HL60, REH, C6, L929 and B16). The results obtained on the basis of flow cytometry indicated that apoptosis could be possible mechanism of cell death.

Antimicrobial activity of copper (II) complex with 1,2-bis [(1,3-diphenylpyrazol-4-yl)methyl] diaminoethane / Antimicrobial activity of copper (II) complex with 1,2-bis [(1,3-diphenylpyrazol-4-yl)methyl] diaminoethane

Background: Multi-resistant strains multiply daily, populate farms, hospitals and other ecological niches around the world, and cause serious infections in animals and humans, often leading to a fatal outcome. Researchers of all profiles are investigating intensively to fi nd new substances with antimicrobial activity. In the period between 1981 and 2002, 163 new chemical compounds were approved for use as drugs. Synthesized compounds have become much more interesting than the natural ones in the production of new antimicrobial agents. Some of these synthesized compounds are Copper (II) complex. The antimicrobial properties of copper were known in ancient Egypt (2000 BC), where it was used to sterilize water and wounds. Copper is still interesting for todays research. Materials, Methods & Results: Antimicrobial activity was tested using a microdilution method according to Clinical and Laboratory Standards Institute. The percentage of surviving bacteria was calculated in comparison to the number of bacteria placed in each well. Based on these results, using the Excel software package from Microsoft Office 2007, graphs were generated that showed the percentage of surviving bacteria depending on the corresponding effective concentrations of the tested substance. The function, which was used to approximate the experimental results, was determined using the Power Trendline supp

Background: Multi-resistant strains multiply daily, populate farms, hospitals and other ecological niches around the world, and cause serious infections in animals and humans, often leading to a fatal outcome. Researchers of all profiles are investigating intensively to fi nd new substances with antimicrobial activity. In the period between 1981 and 2002, 163 new chemical compounds were approved for use as drugs. Synthesized compounds have become much more interesting than the natural ones in the production of new antimicrobial agents. Some of these synthesized compounds are Copper (II) complex. The antimicrobial properties of copper were known in ancient Egypt (2000 BC), where it was used to sterilize water and wounds. Copper is still interesting for todays research. Materials, Methods & Results: Antimicrobial activity was tested using a microdilution method according to Clinical and Laboratory Standards Institute. The percentage of surviving bacteria was calculated in comparison to the number of bacteria placed in each well. Based on these results, using the Excel software package from Microsoft Office 2007, graphs were generated that showed the percentage of surviving bacteria depending on the corresponding effective concentrations of the tested substance. The function, which was used to approximate the experimental results, was determined using the Power Trendline supp

Antimicrobial activity of copper (ii) complex with 1, 2-bis [(1, 3-diphenylpyrazol-4-yl)methyl] diaminoethane

Background: Multi-resistant strains multiply daily, populate farms, hospitals and other ecological niches around the world, and cause serious infections in animals and humans, often leading to a fatal outcome. Researchers of all profiles are investigating intensively to find new substances with antimicrobial activity. In the period between 1981 and 2002, 163 new chemical compounds were approved for use as drugs. Synthesized compounds have become much more interesting than the natural ones in the production of new antimicrobial agents. Some of these synthesized compounds are Copper (II) complex. The antimicrobial properties of copper were known in ancient Egypt (2000 BC), where it was used to sterilize water and wounds. Copper is still interesting for today's research. Materials, Methods & Results: Antimicrobial activity was tested using a microdilution method according to Clinical and Laboratory Standards Institute. The percentage of surviving bacteria was calculated in comparison to the number of bacteria placed in each well. Based on these results, using the Excel software package from Microsoft Office 2007, graphs were generated that showed the percentage of surviving bacteria depending on the corresponding effective concentrations of the tested substance. The function, which was used to approximate the experimental results, was determined using the Power Trendline supplement from the Microsoft Excel program. Cytotoxicity (growth inhibition) was evaluated by tetrazolium colorimetric MTT assay, after exposure of cells to the tested compound for 48 h. Inhibition of growth was expressed as a percentage of cytotoxicity and calculated according to the following equation: (1-A test/A control) x 100. MBC99.9 and MIC99 of the test substance were lowest for Arcanobacterium haemolyticum being 0.2 mg/L and 0.0054 mg/L, respectively. The highest values were obtained for Arcanobacterium pyogenes and methicillin-resistant Staphylococcus aureus (MRSA) 488.002 mg/L and 20.2 mg/L. MIC80 for all four strains ranged from 0.00002 to 0.0023 mg/L. Measured values for MIC99 are 0.00545 mg/L for A. haemolyticum, 0.0443199 mg/L for R. equi, 0.0520712 mg/L for S. aureus and 2.36378 mg/L for A. pyogenes. Values for MIC99.9 ranged from 0.236134 to 488,002 mg/L. Most of the MIC values obtained in this study are significantly lower than those reported by other researchers. The values we obtained were lower as compared to MIC values for standard antibiotics, which were considered acceptable by the relevant institutions. This speaks in favor of a stronger antibacterial effect of our tested substances. In regards to cytotoxicity, the obtained MIC80 doses were lower than toxic, whereas MIC90 could be classified as low-toxic (less than 0.0625 µM), except of Arcanobacterium pyogenes only. According to the IC50 values, the compound Cu (L) Br2·MeOH was 6.4-fold and 4.8-fold more potent against HCT116 cells compared to normal lung fi broblasts and SW620 cells, respectively. Discussion: Copper (II) complex with an arylpyrazole ligand exhibits strong antibacterial properties, and it shows bacteriostatic effect at concentrations where there is no cytotoxic effect in normal human cells. The emergence of multi-resistant strains of pathogenic bacteria is a growing problem worldwide. Therefore, each new compound with potential antimicrobial activity, especially if it is not cytotoxic in effective dosage, deserves the attention of the scientific community. In this paper, we presented a newly synthesized substance with such properties.

Transition metal complexes with thiosemicarbazide-based ligands. LIII. [4-(2-Diphenylphosphino-alpha-ethoxybenzyl-kappaP)-S-methyl-1-(4-oxidopent-3-en-4-ylidene-kappaO)thiosemicarbazido-kappa(2)N(1),N(4)]nickel(II).

The title compound, [Ni(C(28)H(30)N(3)O(2)PS)], crystallizes with two independent molecules in the asymmetric unit. The Ni(II) atoms are in significantly deformed square-planar environments formed by an ONNP donor set from a thiosemicarbazide-based tetradentate ligand. The Ni(II) atom and the ONN donor atoms are nearly coplanar, while the P atom deviates from their mean planes by 0.278 (4) and 0.202 (4) Angstrom for the two independent molecules. The P-containing chelate rings are remarkably non-planar, adopting a boat conformation, which is unusual for chelate rings in transition metal complexes with thiosemicarbazide-based tetradentate ligands. The orientation of the ethoxy group bonded to this chelate ring is caused by an intramolecular C-H...pi interaction with the opposing phenyl ring. There are no hydrogen bonds; instead, numerous intermolecular C-H...pi interactions dominate in the crystal packing.

Transition metal complexes with pyrazole-based ligands. XXII. Part XXI: Mészáros Szécsényi, Leovac, Kovacs, Pokol & Jacimovic (2005). Di-mu-thiocyanato-bis[(3,5-dimethyl-1H-pyrazole-1-carboxamidine-kappa2N,N')(thiocyanato-kappaN)copper(II)] and a redetermination of bis(3,5-dimethyl-1H-pyrazole-1-carboxamidine-kappa2N,N')bis(nitrato-kappaO)copper(II).

The title Cu(II) complex, [Cu2(NCS)4(C6H10N4)2], represents the first crystal structure of a polynuclear transition metal complex with the 3,5-dimethyl-1H-pyrazole-1-carboxamidine ligand (HL). It is compared with previously reported crystal structures of metal complexes with the same HL ligand. The molecule contains an eight-membered binuclear Cu2(NCS)2 ring, which is centrosymmetric and in a chair conformation. The Cu atom has a distorted square-pyramidal geometry with a very elongated Cu-S bond of 2.993 (2) A. The crystal structure redetermination of the bis(3,5-dimethyl-1H-pyrazole-1-carboxamidine-kappa(2)N,N')bis(nitrato-kappaO)copper(II)complex, [Cu(NO3)2(C6H10N4)2], and analysis of its hydrogen bonds confirm the significance of the NO3 groups in the formation of a three-dimensional hydrogen-bonding network. Both complexes are centrosymmetric, the inversion centre being located at the mid-point of the Cu...Cu line in (I) and the Cu atom being located at the inversion centre in (II).

Transition metal complexes with thiosemicarbazide-based ligands. XLIV. Aqua(3-hydroxy-5-hydroxymethyl-2-methylpyridine-4-carboxaldehyde 3-methylisothiosemicarbazone-kappa(3)O,N1,N4)nitratocopper(II) nitrate.

Part XLIII: Novakovic et al. (2002). The title complex, [Cu(NO(3))(C(10)H(14)N(4)O(2)S)(H(2)O)](NO(3)), is the first metal complex with a Schiff base derived from isothiosemicarbazide and pyridoxal (pyridoxal is 3-hydroxy-5-hydroxymethyl-2-methylpyridine-4-carboxaldehyde). The Cu(II) environment is a square pyramid, the equatorial plane of which is formed by the tridentate ONN-coordinated isothiosemicarbazone and one water molecule, while the nitrate ligand is in the apical position. The existence of numerous strong intermolecular hydrogen bonds, and weak C-H...O and C-H...pi interactions, leads to a three-dimensional supramolecular structure.

Dibromo(pyridoxal semicarbazone-kappa3N1,O3,O3')copper(II).

The title compound, dibromo(3-hydroxy-5-hydroxymethyl-2-methyl-4-pyridinecarboxaldehyde semicarbazone-kappa(3)N(1),O(3),O(3'))copper(II), [CuBr(2)(C(9)H(12)N(4)O(3))], consists of discrete complex units with the tridentate pyridoxal semicarbazone ligand as a zwitterion in an almost planar configuration. The Cu(II) ions are in a distorted square-pyramidal coordination, with the equatorial Br atom at a distance of 2.4017 (6) A and the apical Br atom at a distance of 2.6860 (6) A.

Tris(3,5-dimethyl-1H-pyrazole-1-thiocarboxamidato-kappa(2)N(2),N)cobalt(III).

In the crystal structure of the title complex, [Co(C(6)H(8)N(3)S)(3)], the Co(III) atom is octahedrally coordinated by three monodeprotonated bidentate 3,5-dimethyl-1H-pyrazole-1-thiocarboxamide ligands with two thiocarboxamide N atoms in axial positions. The asymmetric unit contains two molecules (A and B) and these molecules are arranged in chains in an alternating fashion connected by N-H...S interactions.

Transition metal complexes with thiosemicarbazide-based ligands. XLIII. Chlorobis(3-methylisoemicarbazide-kappa(2)N(1),N(4))zinc(II) chloride.

In the title compound, [ZnCl(C(2)H(7)N(3)S)(2)]Cl, the Zn(II) ion is five-coordinated in a distorted trigonal-bipyramidal arrangement, with the hydrazine N atoms located in the apical positions. The structure is stabilized by N[bond]H...Cl hydrogen bonds, which involve both the Cl atoms and all the hydrogen donors, except for one of the two thioamide N atoms. A comparison of the geometry of thiosemicarbazide and S-methylisothiosemicarbazide complexes with Zn(II), Cu(II) and Ni(II) shows the pronounced influence of the hydrogen-bond network on the coordination geometry of Zn(II) compounds.

Antimicrobial activity of copper (II) complex with 1,2-bis [(1,3-diphenylpyrazol-4-yl)methyl] diaminoethane / Antimicrobial activity of copper (II) complex with 1,2-bis [(1,3-diphenylpyrazol-4-yl)methyl] diaminoethane

Background: Multi-resistant strains multiply daily, populate farms, hospitals and other ecological niches around the world, and cause serious infections in animals and humans, often leading to a fatal outcome. Researchers of all profiles are investigating intensively to fi nd new substances with antimicrobial activity. In the period between 1981 and 2002, 163 new chemical compounds were approved for use as drugs. Synthesized compounds have become much more interesting than the natural ones in the production of new antimicrobial agents. Some of these synthesized compounds are Copper (II) complex. The antimicrobial properties of copper were known in ancient Egypt (2000 BC), where it was used to sterilize water and wounds. Copper is still interesting for todays research. Materials, Methods & Results: Antimicrobial activity was tested using a microdilution method according to Clinical and Laboratory Standards Institute. The percentage of surviving bacteria was calculated in comparison to the number of bacteria placed in each well. Based on these results, using the Excel software package from Microsoft Office 2007, graphs were generated that showed the percentage of surviving bacteria depending on the corresponding effective concentrations of the tested substance. The function, which was used to approximate the experimental results, was determined using the Power Trendline supp

Background: Multi-resistant strains multiply daily, populate farms, hospitals and other ecological niches around the world, and cause serious infections in animals and humans, often leading to a fatal outcome. Researchers of all profiles are investigating intensively to fi nd new substances with antimicrobial activity. In the period between 1981 and 2002, 163 new chemical compounds were approved for use as drugs. Synthesized compounds have become much more interesting than the natural ones in the production of new antimicrobial agents. Some of these synthesized compounds are Copper (II) complex. The antimicrobial properties of copper were known in ancient Egypt (2000 BC), where it was used to sterilize water and wounds. Copper is still interesting for todays research. Materials, Methods & Results: Antimicrobial activity was tested using a microdilution method according to Clinical and Laboratory Standards Institute. The percentage of surviving bacteria was calculated in comparison to the number of bacteria placed in each well. Based on these results, using the Excel software package from Microsoft Office 2007, graphs were generated that showed the percentage of surviving bacteria depending on the corresponding effective concentrations of the tested substance. The function, which was used to approximate the experimental results, was determined using the Power Trendline supp