Lasing the DNA fragments through β-diketimine framed Knoevenagel condensed Cu(II) and Zn(II) complexes--an in vitro and in vivo approach

New Copper Complexes with N,O-Donor Ligands Based on Pyrazole Moieties Supported by 3-Substituted Acetylacetone Scaffolds

The new 3-monosubstituted acetylacetone ligands, 3-(phenyl(1H-pyrazol-1-yl)methyl)pentane-2,4-dione (HLacPz) and 3-((3,5-dimethyl-1H-pyrazol-1-yl)(phenyl)methyl)pentane-2,4-dione (HLacPzMe), were synthesized and used as supporting ligands for new copper(II) and copper(I) phosphane complexes of the general formulae [Cu(HLacX)2(LacX)2] and [Cu(PPh3)2(HLacX)]PF6 (X = Pz (pyrazole) or PzMe (3,5-dimethylpyrazole)), respectively. In the syntheses of the Cu(I) complexes, the triphenylphosphine coligand (PPh3) was used to stabilize copper in the +1 oxidation state, avoiding oxidation to Cu(II). All compounds were characterized by CHN analysis, 1H-NMR, 13C-NMR, FT-IR spectroscopy, and electrospray ionization mass spectrometry (ESI-MS). The ligands HLacPz (1) and HLacPzMe (2) and the copper complex [Cu(PPh3)2(HLacPz)]PF6 (3) were also characterized by X-ray crystallography. The reactivity of these new compounds was investigated and the new compounds 4-phenyl-4-(1H-pyrazol-1-yl)butan-2-one (7) and 4-(3,5-dimethyl-1H-pyrazol-1-yl)-4-phenylbutan-2-one (8) were obtained in basic conditions via the retro-Claisen reaction of related 3-monosubstituted acetylacetone, providing efficient access to synthetically useful ketone compounds. Compound 8 was also characterized by X-ray crystallography.

Schiff base compounds as artificial metalloenzymes

Much research has been done on traditional homogeneous metal catalysts and enzymatic catalysts, but recently a new class of hybrid catalysts called synthetic (artificial) metalloenzymes has been considered by researchers. Metalloenzymes as hybrid catalysts (host-guest systems) have been shown that combine the properties of a homogeneous and also enzymatic catalyst. The hybrid catalyst will have added value such as enantioselectivity or chemo-selectivity. This review focuses on Schiff base complexes that either act as homogeneous artificial enzymes or contribute to the structure of a host in the preparation of hybrid metalloenzymes. Because this approach can virtually be applied to any bio- or synthetic host or guest coordination complex, the details of hybrid catalysts seem important for advance in catalysis.

Investigation of in vitro anticancer and DNA strap interactions in live cells using carboplatin type Cu(II) and Zn(II) metalloinsertors

A series of carboplatin type Cu(II) and Zn(II) metalloinsertors (1-8) having β-diketone analogues and biologically significant cyclobutane-1,1-dicarboxylic acid have been synthesized and characterized by spectral and analytical methods. The binding and cleavage propensity of these metalloinsertors on DNA and their cytotoxic effects in live cells have been explored. From the gel electrophoresis study, it is observed that the complexes 1-8 cleave pBR322 DNA via a hydrolytic mechanism induced by hydroxyl radical scavengers, DMSO and EtOH as the reactive oxygen species (ROS). In vivo antitumor efficacy has been studied on EAC tumor bearing mice which is assessed by mean survival time, effect on hematological parameters and solid tumor volume. The results strongly support that complex 1 shows potent antitumor effect against EAC and higher than the standard drug carboplatin. Moreover, the cytotoxicity of the complexes, screened on a panel of human cancerous cell lines viz., human cervical cancer cells (HeLa), human breast adenocarcinoma cells (MCF-7), human laryngeal epithelial carcinoma cells (HEp-2), human liver carcinoma cells (Hep G2) and non-cancerous NIH 3T3 mouse embryonic fibroblasts cell lines, reveals that complex 1 exhibits a better anticancer activity than other complexes and standards.