37526-16-2

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• 87-69-4 L-Tartaric acid 
• 95-54-5 1,2-diamino-benzene 
• 147-71-7 D-tartaric acid 

Relevant academic research and scientific papers

DNA interaction and anticancer evaluation of new palladium(II), platinum(II) and silver(I) complexes based on (Δ)- and (Λ)-1,2–bis-(1H-benzimidazol-2-yl)-1,2-ethanediol enantiomers

The synthesis of some new palladium(II), platinum(II) and silver(I) complexes based on (Δ)- and (Λ)-1,2–bis-(1H-benzimidazol-2-yl)-1,2-ethanediol (Δ-H2bie and Λ-H2bie) enantiomers in the absence and presence of the N,N-chelates 2,2′-bipyridyl and 9,10-phenanthroline, and triphenylphosphine is reported. The molecular structures of the new complexes are discussed on the basis of their IR, Raman, UV–Vis, NMR (1H, 13C and 31P) and mass spectra, elemental analyses, molar conductivities and TGA properties. Both Δ-H2bie and Λ-H2bie coordinate to the metal ions in a neutral bidentate manner through the azomethine-N and protonated hydroxy-O atoms, while in basic media, Δ-Hbie? and Λ-Hbie? are bound to the metal ions through the azomethine-N and deprotonated-O atoms as mono-negative bidentate chelating ligands. The in vitro anticancer activity of the complexes has been evaluated against the human breast cancer (MDA-MB231) and ovarian cancer (OVCAR-8) cell lines. The Δ-H2bie complexes are more active against the studied cell lines. The IC50 values for cell growth proliferation of [Ag(PPh3)(Λ-H2bie)]ClO4 and [Ag(PPh3)(Δ-Hbie)] are 0.443 and 1.277 μM, and 0.427 and 1.437 μM for the MDAMB231 and OVCAR-8 cell lines, respectively. The corresponding IC50 values for cisplatin were 3.20 (MDA-MB231) and 2.28 (OVCAR-8) μM. The DNA-binding properties of some of the complexes have been studied using circular dichroism (CD) spectroscopy. The results indicate that the complexes may have intercalative CT-DNA binding capabilities. The intercalation of the Δ-enantiomers appears to be greater than is that for the Λ-enantiomers. Insertion of the complexes into adjacent base pairs prevents neighboring base pairs from close stacking.

De novo design, synthesis and spectroscopic characterization of chiral benzimidazole-derived amino acid Zn(II) complexes: Development of tryptophan-derived specific hydrolytic DNA artificial nuclease agent

Novel ternary dizinc(II) complexes 1-3, derived from 1,2-bis(1H- benzimidazol-2-yl)ethane-1,2-diol and l-form of amino acids (viz., tryptophan, leucine and valine) were synthesized and characterized by spectroscopic (IR, 1H NMR, UV-vis, ESI-MS) and other analytical methods. To evaluate the biological preference of chiral drugs for inherently chiral target DNA, interaction of 1-3 with calf thymus DNA in Tris-HCl buffer was studied by various biophysical techniques which reveal that all these complexes bind to CT DNA non-covalently via electrostatic interaction. The higher Kb value of l-tryptophan complex 1 suggested greater DNA binding propensity. Further, to evaluate the mode of action at the molecular level, interaction studies of complexes 1 and 2 with nucleotides (5′-GMP and 5′-TMP) were carried out by UV-vis titrations, 1H and 31P NMR which implicates the preferential selectivity of these complexes to N3 of thymine rather than N7 of guanine. Furthermore, complex 1 exhibits efficient DNA cleavage with supercoiled pBR322. The complex 1 cleaves DNA efficiently involving hydrolytic cleavage pathway. Such chiral synthetic hydrolytic nucleases with asymmetric centers are gaining considerable attention owing to their importance in biotechnology and drug design, in particular to cleave DNA with sequence selectivity different from that of the natural enzymes.

Synthesis, characterization, biological studies (DNA binding, cleavage, antibacterial and topoisomerase I) and molecular docking of copper(II) benzimidazole complexes

To explore the therapeutic potential of copper-based benzimidazole complexes, tetranuclear Cu(II) complex 1 and dinuclear ternary amino acid complexes 2 and 3 {L-trp and L-val, respectively} were synthesized and thoroughly characterized. In vitro DNA binding studies of complexes 1-3 were carried out employing UV-vis titrations, fluorescence, circular dichroic and viscosity measurements which revealed that the complexes 1-3 bind to CT DNA preferably via groove binding. Complex 1 cleaved pBR322 DNA via hydrolytic pathway (validated by T4 DNA ligase assay), accessible to major groove while 2 followed oxidative mechanism, binding to minor groove of DNA double helix; binding events were further validated by molecular docking studies. Additionally, the complexes 1 and 2 exhibit high Topo-I inhibitory activity at different concentrations. The complexes 1-3 were evaluated for antibacterial activity against Escherichia coli and Staphylococcus aureus, and 2 was found to be most effective against Gram-positive bacteria.

In vitro binding studies of organotin(IV) complexes of 1,2-bis(1H- benzimidazol-2-yl)ethane-1,2-diol with CT-DNA and nucleotides (5′-GMP and 5′-TMP): Effect of the ancillary ligand on the binding propensity

The chiral benzimidazole ligand, 1,2-Bis(1H-benzimidazol-2-yl)ethane-1,2- diol, L, exhibiting coordination mode with an oxygen atom of alcohol group directed towards the metal ion and another -OH group with different molecular axis directed away from the metal center was utilized as a building block for organotin complexes [C18H19N4O 2SnCl], [C28H23N4O2SnCl] and [C52H42N4O2Sn2] (1-3). Complexes 1 and 3 exhibit a pentacoordinate geometry while the complex 2 reveals hexacoordinated environment around the Sn(IV) metal ions as evidenced by 119Sn NMR studies. The DNA binding ability of benzimidazole ligand and their organotin(IV) complexes 1-3 were examined by employing different biophysical methods. The absorption titration of the complexes with CT-DNA reveal significant hyperchromic effect together with strong bathochromic shift of 4-5 nm which infer substantial binding of the complexes with CT-DNA. The intrinsic binding constant Kb values of the complexes 1-3 were found to be 2.16 ± 0.04 × 104, 3.47 ± 0.04 × 104 and 4.60 ± 0.04 × 103 M-1, respectively, suggesting pronounced binding of complex 2 with DNA double helix. The mechanism of binding of the complexes was further ascertained by the interaction studies of these complexes with nucleotides (5′-GMP and 5′-TMP) using absorption spectroscopy suggesting a clear preference for 5′-GMP binding which was further authenticated by NMR (1H and 31P NMR) studies.

1,2-Bis(2-benzimidazolyl)-1,2-ethanediol, a chiral, tridentate, facially coordinating ligand

The ligand 1,2-bis(1H-benzimidazol-2-yl)-1,2-ethanediol, 1, and its methylated derivative 2 are readily synthesized from tartaric acid, and act as chiral, facially coordinating tridentate ligands, forming complexes of composition ML2 with octahedral transition metals. The copper(II) complexes show distorted 4 + 2 coordination with benzimidazoles occupying the equatorial sites and alcohol functions weakly binding in the axial sites. Nickel(II) complexes in three different states of protonation show regular octahedral geometry with the alcohols mutually cis. Deprotonation of the coordinated alcohol produces little structural change but the monodeprotonated complex forms a hydrogen bonded dimer. Magnetic measurements show the hydrogen bonded bridge to offer a pathway for weak antiferromagnetic coupling. UV-Visible spectroscopy shows the ligand to have a field intermediate between water and pyridine. The diastereoselectivity of complexation depends on the geometry: nickel(II) shows a weak preference for the homochiral complex, whereas copper(II) forms almost exclusively homochiral complexes.