J. Casanova

COORDINATION BEHAVIOR OF SULFATHIAZOLE. CRYSTAL STRUCTURE OF CU(SULFATHIAZOLE) (PY)3CL SUPEROXIDE DISMUTASE ACTIVITY

Abstract The preparation, spectroscopic, magnetic properties, and crystal structure of [Cu(stzxpy) 3 Cl] (stz − stands for the deprotonated form of sulfathiazole, 4-amino-N-2-thiazolylbencenosulfonamide) are reported. Crystals are orthorhombic, space group Pbca, with cell constants a = 15.834(2), b = 17.512(4), and c = 18.79(2) A, and Z = 8. The structure was solved and refined to R = 0.041 (R W = 0.040). The structure consists of mononuclear units linked via hydrogen bonds to form the tridimensional pyramid. The geometry of CuN3N*NCl chromophore is distorted square-pyramid. The superoxide-dismutase mimetic activity of the compound is measured and compared with those of the SOD enzyme, the free drug, and other related sulfathiazole complexes.

Superoxide dismutase activity of ternary copper complexes of sulfathiazole and imidazole derivatives. Synthesis and properties of [CuL2(R-Him)2] [HL=4-amino-N-(thiazol-2-yl)benzenesulfonamide, R-Him=4-methylimidazole, 4,4-dimethylimidazoline or 1,2-dimethylimidazole]. Crystal structure of [CuL2(4,4-dimethylimidazoline)2]

Abstract New ternary copper(II) complexes of sulfathiazole (4-amino-N-(thiazol-2-yl)benzenesulfonamide)(HL) and methyl imidazole derivatives have been synthesised and characterised. The crystal structure of the complex [CuL2(4,4-dmHim)2] (1) [4,4-dmHim=4,4-dimethylimidazoline] has been determined. The copper centre has a quasi regular square planar environment with Cu-nitrogen bond lengths ranging from 1.952 to 2.010 A. From the spectroscopic properties of the complexes [CuL2(1,2-dmHim)2] (2) [1,2-dmHim=1,2-dimethylimidazole] and [CuL2(4-mHim)2] (3) [4-mHim=4-methylimidazole] a distorted tetragonal octahedral geometry is deduced. The compounds showed SOD mimetic activity in fact, a low concentration of the complexes catalyses the dismutation of superoxide at biological pH. This SOD activity is correlated with their structural properties. Using Extended Huckel Molecular Orbital Calculations the one-electron energy levels of the CuN4 chromophore in complex 1 are reported and correlated with the data of the CuN6 and CuN5 chromophores of the previously reported [CuL2(Him)2]·MeOH and [CuL2(mim)2]·H2O compounds. In addition, the influence of the geometry distortion on the composition and energy of the molecular orbitals is described using idealised models.

Metal complexes of sulfanilamide derivatives. Crystal structure of [Zn(sulfathiazole)2]·H2O

Abstract The crystal structure of the Zn(sulfathiazole) 2 ·H 2 O complex is reported. The complex crystallizes in the monoclinic space group C 2/ c . The cell dimensions are a = 9.098(3) A, b = 17.871(5) A, c = 14.61(1) A, β = 99.44(6)°, V = 2343(2) A 3 , Z = 4, and D x = 1.68 g/cm 3 . The final conventional R-factor = 0.027 for 2669 “observed” reflections and 191 variables. The Zn ion is surrounded in a regular tetrahedral arrangement by two N amino and two N thiazole atoms pertaining to four sulfathiazole (Hstz) ligands. Each stz anion, acting as a bidentate ligand, chelates to two Zn ions as a bridge through the N thiazole and the N amino atoms. The IR, 13 C NMR in solid state, 1 H NMR, and 13 C NMR in DMSO d6 solutions spectra are discussed in detail with regard to the crystal structure.

Coordination behavior of sulfathiazole. Crystal structure of dichloro-disulfathiazole ethanol Cu(II) complex. Superoxide dismutase activity

Abstract The crystal structure of [Cu(sulfathiazole) 2 (EtOH)Cl 2 ) (triclinic; a = 7.82(1), b = 11.441(3), c = 16.606(6) A, α = 109.68(4), β= 102.24(4), γ 91.27(4)°, Z = 2, space group P 1 ) has been determined from the intensities of 2605 independent reflections (graphite monochromator MoKα; 4-circle diffractometer; R = 4.5%). The coordination polyhedron around Cu(II) ion is intermediate between square pyramid are trigonal bipyramid. The spectroscopic data and the rhombic powder EPR spectrum are in agreement with the distorted geometry of the Cu(II) ion. The superoxide dismutase activity of the title compound has been measured and compared with those of the free drug and other sulfathiazole complexes.

Crystal structures and superoxide dismutase mimetic activity of [CuL2(Him)2]·MeOH and [CuL2(mim)2]·H2O [HL = 4-amino-N-(thiazol-2-yl)benzenesulfonamide, Him = imidazole, mim =N-methylimidazole]

The complexes [CuL2(Him)2]·MeOH 1 and [CuL2(mim)2]·H2O 2[HL = 4-amino-N-(thiazol-2-yl)-benzenesulfonamide, Him = imidazole, mim =N-methylimidazole] have been prepared and their crystal structures determined. In 1 the metal centre has a very irregular stereochemistry, being co-ordinated by six nitrogen atoms, two of them from the imidazole ligands and the other four from three sulfonamides, one belonging to an adjacent asymmetric unit. The crystal packing shows stacking interactions between the imidazole and phenyl rings of the sulfonamide. In 2 the co-ordination polyhedron is intermediate between square pyramidal and trigonal bipyramidal. Spectroscopic and electrochemical data are in accord with the crystal structures. The in vitro O2– scavenger activity of the complexes shows that they exhibit high superoxide-dismutase mimetic activity.

Metal complexes of 5-tertbutyloxycarbonylamido-1,3,4-thiadiazole-2-sulfonamide (B-H2ats), a carbonic anhydrase inhibitor. Synthesis and characterization of the copper(II) complex. Crystal structures of B-H2ats and the [Cu(B-ats)(NH3)2]2 dimer complex

Abstract A new acetazolamide derivative, 5-tertbutyloxycarbonylamido-1,3,4-thiadiazole-2-sulfonamide (B-H 2 ats), has been prepared and examined as a chelating agent towards copper(II) ion. The crystal structures of the ligand and the [Cu(B-ats)(NH 3 ) 2 ] 2 complex were determined by single-crystal X-ray diffraction. Crystal data for B-H 2 ats: a = 11.246(3), b = 9.10(1), c = 12.486(5) A , β = 100.94(6)°, Z = 4 and V = 1255(2) A 3 . The refinement of the structure based on 1454 reflections yielded R = 0.041 and wR = 0.046. Crystal data of the copper(II) complex: a = 7.084(7), b = 7.970(4), c = 13.76(1) A , α = 105.70(5), β = 97.99(5)°, γ = 99.08(7)°, Z = 1 and V = 725(1) A 3 . The refinement of the structure based on 850 reflections yielded R = 0.064 and wR = 0.061. The two copper(II) ions, linked by two thiadiazole NN groups from two adjacent B-ats ligands form a nearly planar six-membered ring with a copper-copper distance of 4.27(2) A. The coordination polyhedron around the copper is intermediate between a square pyramid and a trigonal bipyramid. The magnetic susceptibilities measured from 4.7 K show a weak antiferromagnetic spin coupling. The IR, reflectance diffuse and EPR spectra and the thermal properties were studied.

Synthesis and characterization of metal(II)-8-quinolinsulfonamidato (sa−) complexes (M = Co, Ni, Cu, and Zn). Crystal Structure of [Zn(sa)2(NH3)].NH3 complex. carbonic anhydrase inhibitory properties

A new sulfonamide, 8-quinolinsulfonamide(Hsa), has been prepared and examined as a chelating agent towards metal(II) ions. The spectroscopic properties of the M(II) sulfonamidato complexes has been studied. The inhibitory properties of the ligand and the synthesised complexes were tested. The crystal structure of the [Zn(sa)2(NH3)].NH3 complex was determined by single-crystal X-ray diffraction. Crystal data of the zinc(II) complex: a = 16.217(4)A, b = 8.041(1)A, c = 15.606(4)A, beta = 95.75(1) degrees, Z = 4, and V = 2024.6(7)A3. The refinement of the structure based on 6047 reflections attained to R = 0.049 and Rw = 0.052. The zinc(II) ion is surrounded by four N atoms of two sulfonamidato ligands and one N atom of an ammonia molecule in an trigonal bipyramid arrangement.

Copper complexes modelling the interaction between benzolamide and Cu-substituted carbonic anhydrase. Crystal structure of Cu(bz)(NH3)4 complex

New copper benzolamide (H 2 bz, 5-phenylsulfonamide-1,3,4-thiadiazole-2-sulfonamide) complexes with ammonia, diethylentriamine (dien) and dipropylentriamine (dipn) have been prepared. The complex [Cu(bz)(NH 3 ) 4 ] crystallises in the monoclinic space group P 2 1 / n with a = 7.621(3), b = 19.91(5), c = 11.291(3) A, β = 93.17(4)° and Z = 4. The Cu(II) is five-coordinated with an almost regular square pyramidal geometry. The dideprotonated sulfonamide behaves as monodentate ligand interacting with the metal ion through the N atom of the unsubstituted sulfonamide group. In the EPR spectrum, exchange coupling between Cu(II) polyhedra of different orientations in the unit cell is observed. The dien and dipn ligands provide a model of the histidine environment of the metal ion in carbonic anhydrase (CA). From the spectroscopic properties, the ternary triamine complexes can be considered as analogous of the adducts formed by Cu-CA and the inhibitor benzolamide.

Metal complexes of sulfanilamide derivatives. Spectroscopic characterization of the dichloro disulfathiazole methanol copper(II) complex

The synthesis and spectral characterization of the [Cu(Hstz)2(MeOH)Cl2] complex are described. Both polycrystalline powder EPR and single crystal EPR spectra recorded at room temperature show rhombic distortion with values of g1=2.25, g2=2.09 and g3=2.03 in agreement with a copper polyhedron, intermediate between trigonal bipyramid and square pyramidal.

Complexes With Biologically Active Ligands. Part 61 Ni(II)Coordination Compounds of Hydrazine and Heterocyclic Sulfonamidesas Inhibitors of the Zinc Enzyme Carbonic Anhydrase

Ternary Ni(II) complexes of hydrazine and eight heterocyclic sulfonamides possessing carbonic anhydrase (CA) inhibitory properties, were prepared and characterized by elemental analysis, spectroscopic, magnetic, thermogravimetric, and conductimetric measurements. The complexes behave as strong inhibitors for two isozymes (I and II) of carbonic anhydrase.