RESUMO

The tri-dentate Schiff base ligand 3-(2-hydroxyethylimino)-1-phenylbut-1-en-1-ol (L) produced the tetra-nuclear Cu(II) distorted cubane complex which contain Cu4O4 core, upon reaction with Cu(II)acetate.H2O. The complex was structurally characterized by X-ray crystallography and found that, in this tetrameric and tetra-nuclear distorted cubane structure, each two-fold deprotonated Schiff base ligand coordinated to a Cu(II) center with their alcoholic oxygens and imine nitrogens and formed six and five-membered chelate rings. At the same time, each ligand bridged to a neighboring Cu(II) atom by its alcoholic oxygen, thus the metal centers became penta-coordinated. The copper(II) complex with µ-ɳ2-hydroxo bridges and Cu….Cu distance about 3 Šwas structurally similar to the active site of natural catechol oxidase enzyme and exhibited excellent catecholase activity in aerobic oxidation of 3,5-di-tert-butyl catechol to its o-quinone. The kinetics and mechanism of the oxidation of 3, 5-DTBCH2 catalyzed by [CuL]4 complex, were studied at four different temperatures from 283 to 313K by UV-Vis spectroscopy. Interaction of [CuL]4 complex with FS-DNA was investigated by UV-Vis and fluorescence spectroscopy, viscosity measurements, cyclic voltammetry (CV), circular dichroism (CD) and agarose gel electrophoresis. The main mode of binding of the complexes with DNA was intercalation. The interaction between [CuL]4 complex and bovine serum albumin (BSA) was studied by UV-Vis, fluorescence and synchronous fluorescence spectroscopic techniques. The results indicated a high binding affinity of the complex to BSA. In vitro anticancer activity of the complex was evaluated against A549, Jurkat and Ragi cell lines by MTT assay. The complex was remarkably active against the cell lines and can be a good candidate for an anticancer drug. Theoretical docking studies were performed to further investigate the DNA and BSA binding interactions.

Assuntos

Complexos de Coordenação/farmacologia , Cobre/farmacologia , DNA/metabolismo , Substâncias Intercalantes/farmacologia , Soroalbumina Bovina/metabolismo , Animais , Catálise , Catecol Oxidase/química , Catecóis/química , Bovinos , Complexos de Coordenação/química , Cobre/química , Cristalografia por Raios X , Substâncias Intercalantes/química , Modelos Moleculares , Oxirredução/efeitos dos fármacos , Temperatura

RESUMO

The methyl-substituted imidazolidine ring of the title compound, C24H26N2O2, adopts an envelope conformation with the N atom adjacent to the methyl-ene group as the flap. The meth-yl-ethyl-ene fragment in this ring is disordered over two positions with an occupancy ratio of 0.899 (4):0.101 (4). The hy-droxy-benzyl groups are inclined at 71.57 (15) and 69.97 (19)° to the mean plane of major disorder component of the heterocyclic ring with an inter-planar angle between the two hy-droxy-benzyl groups of 66.00 (5)°. The phenyl substit-uent approaches a nearly perpendicular orientation relative to the mean plane of the imidazolidine ring, making a dihedral angle of 75.60 (12)°. This conformation is stabilized by two intra-molecular O-H⋯N bonds, which generate S(6) ring motifs.

RESUMO

BACKGROUND: The results presented herein show that the cyclic aminal (2S,7R,11S,16R)-1,8,10,17-tetraazapentacyclo[8.8.1.1.(8,17)0.(2,7)0(11,16)]icosane (6), derived from cis-(meso)-1,2-diaminocyclohexane and formaldehyde, is a suitable substrate for the preption of a series of cis-meso Mannich bases such as 8a-l by reaction with p-substituted phenols 7a-l in basic media. These compounds are valuable synthetic products and may find application in asymmetric catalysis. RESULTS: The products were characterized principally by NMR and IR spectroscopy. Both the benzylic and aminalic protons of the perhydrobenzimidazolidine moiety were diastereotopic due to the presence of stereogenic nitrogen centers. The occurrence of intramolecular hydrogen bonding interactions was confirmed by the broad OH stretching vibration band in the IR spectra. Vibrational spectra were calculated using B3LYP at 6-31G(d,p) level, and the calculated frequencies for the νOH vibrations were compared to those of the experimental spectra. Hydrogen bonding interactions in the solid state were observed through the X-ray crystallography of 8j. Additionally, Mulliken charges and Fukui indices for 6 were calculated as theoretical descriptors of electrophilicity. CONCLUSION: A new series of meso Mannich bases called 4,4'-disubstituted-2,2'-{[(3aR,7aS)-2,3,3a,4,5,6,7,7a-octahydro-1H-1,3-benzimidazole-1,3-diyl]bis(methylene)} diphenols (8a-l) which are derived from cis-(meso)-1,2-diaminocyclohexane, were obtained from cyclic aminal 6. These results confirmed the behavior of 6 as an electrophilic preformed reagent in Mannich reactions in basic media.

RESUMO

The title chiral quaternary ammonium salt, C(13)H(25)N(4) (+)·I(-), was synthesized through the Menschutkin reaction between the cage aminal (2S,7S)-1,8,10,12-tetra-aza-tetra-cyclo-[8.3.1.1(8,12).0(2,7)]penta-decane and ethyl iodide. The quaternization occurred regioselectively on the nitrogen with major sp3 character. The crystal structure consists of anions and cations separated by normal distances. Ions are not linked through C-H⋯I hydrogen bonds.

RESUMO

In the title compound, C24H25ClN2, the methine, methyl-ene and methyl C atoms of the methyl-substituted imidazolidine ring are disordered over two sets of sites with a refined occupancy ratio of 0.834 (4):0.166 (4). Each disordered ring assumes an envelope conformation with an N atom as the flap. The pendant benzyl rings are oriented equatorially with respect to the imidazolidine ring. The chloro-phenyl ring is inclined to the mean plane of the four planar atoms of the major component of the imidazolidine ring by 76.27 (12)°. The dihedral angles between the chloro-phenyl ring and the two benzyl rings are 55.31 (9) and 57.50 (8)°; the dihedral angle between these latter rings is 71.59 (9)°. In the crystal, mol-ecules are linked by C-H⋯Cl inter-actions and a number of weak C-H⋯π inter-actions, involving all three aromatic rings, forming a three-dimensional structure.