New 1,2,3-triazoles and their oxime derivatives: AChE/BChE enzyme inhibitory and DNA binding properties.

1,2,3-Triazole compounds (1a-3a) and their oxime derivatives (1b-3b) were synthesized. The structures of these synthesized compounds were characterized using common spectroscopic methods. Crystal structures of the compounds 3, 2b and 3b were determined by single crystal X-ray diffraction studies. The acetylcholinesteras (AChE) and butyrylcholinesterase (BChE) cholinesterase inhibitor (ChEI) and DNA/calf serum albumin (BSA) binding properties of the compounds were examined. DNA binding studies have shown that compounds interact with DNA through 1,2,3-triazole and oxime groups. When the binding constant Kb values were compared, it was revealed that compound 3b (Kb = 4.6 × 105 M-1) with oxime in its structure binds more strongly than the others. In addition, in vitro BSA binding studies showed that compounds 1b and 3b exhibited higher binding affinity. These results confirm that the quenching is due to the formation of a compound resulting from the static quenching mechanism, rather than being initiated by a dynamic mechanism. Likewise, when the enzyme activity of the compounds was examined, the compounds exhibited high inhibitory activity against AChE. The highest activity was observed for compounds 2b and 3b (8.6 ± 0.05 and 4.8 ± 0.052 µM). It was observed that the compounds were not selective with respect to BChE. Communicated by Ramaswamy H. Sarma.

Investigation of photoluminescence and DNA binding properties of benzimidazole compounds containing benzophenone group.

The synthesis of benzimidazole compounds containing benzophenone group in accordance with the literature and the investigation of DNA binding properties of these compounds by using UV-vis and photoluminescence spectroscopy methods constitute the basis of this research. The structures of the compounds were determined by methods such as FT-IR, 1H, 13C NMR, UV-vis, Photoluminescence spectroscopy, and X-ray crystallography. By using methods such as UV-vis, Photoluminescence spectroscopy, and viscosity tests, information were collected about the binding types, binding mode, and binding energies of the compounds with DNA. In addition, the binding interactions of the compounds with DNA were investigated using the molecular docking technique. Using this information, calibration equations, correlation coefficients (r2), and DNA binding constants (Kb) were calculated for their compounds. The binding constants (Kb) calculated for substances A, B, and C were found to be 3.0 × 104, 7.0 × 104, and 3.0 × 104 M-1, respectively. UV-vis, EB competitive binding, and viscosity tests showed that the compounds tended to bind to the DNA structure via the groove binding mode. At the end of molecular docking studies, it was determined that compound B showed the best DNA binding activity in in vitro studies. Compared with the studies in the literature, it is thought that the synthesized compounds can take place in cancer drug research as DNA binding agents.Communicated by Ramaswamy H. Sarma.

Pyrene, Anthracene, and Naphthalene-Based Azomethines for Fluorimetric Sensing of Nitroaromatic Compounds.

Special attention is given to the development of rapid and sensitive detection of nitroaromatic explosives for homeland security and environmental concerns. As part of our contribution to the detection of nitroaromatic explosives, fluorescent materials (A), (B) and (C) were synthesized from the reaction of 1,2-diaminocyclohexane with pyrene-1-carbaldehyde, anthracene-9-carbaldehyde and 2-hydroxy-1-naphthaldehyde, respectively. The structures of the prepared fluorescent azomethine probes were confirmed using FTIR, 1H-NMR and 13C-NMR spectroscopies. The basis of the study is the use of the synthesized materials as fluorescent probes in the photophysical and fluorescence detection of some nitroaromatic explosives. Emission increases occurred due to aggregation caused by π-π stacking in synthesized azomethines. To measure the nitroaromatic detection capabilities of fluorescence probes, fluorescence titration experiments were performed using the photoluminescence spectroscopy. It was observed that compound A containing pyrene ring provided the best emission intensity-increasing effect due to aggregation with the lowest LOD value (14.96 µM) for the sensing of 4-nitrophenol. In compounds B and C, nitrobenzene with the lowest LOD (16.15 µM and 23.49 µM respectively) caused the most regular emission increase, followed by picric acid.

A series of phenanthroline-imine compounds: Computational, OLED properties and fluorimetric sensing of nitroaromatic compounds.

In this study, Schiff base compounds (1-5) were synthesized by the reaction of 5-amino-1,10-phenanthroline with various aldehydes. The molecular structures of the synthesized compounds were characterized by FT-IR, 1H/13C NMR and mass spectroscopic methods. Single crystals of 1 were obtained and their molecular structures in crystalline form were determined by single crystal X-ray diffraction study. The sensor properties of the synthesized compounds against nitroaromatic compounds [nitrobenzene (NB), 4-nitrophenol (NP), 2,4-dintrophenol (DNP) and 1,3,5-trinitrophenol (TNP)] were investigated by fluorescence spectroscopy. Compound 3 have highest sensitivity for the sensing of 1,3,5-trinitrophenol (TNP) (Ksv: 4.63 × 104 M-1) with LOD of 4.01 µM while compound 5 showed the highest sensitivity for 2,4-dinitrophenol (DNP) (Ksv: 5.71 × 104 M-1) with LOD of 4.75 µM. In addition, the structural parameters (bond angles/lengths), contour diagrams of HOMO/LUMO molecular orbitals, molecular electrostatic potential (MEP) maps, non-linear optical (NLO) and OLED properties were investigated by computational studies. According to the HOMO and LUMO energies, the NLO property of the molecule (5) is higher than both other molecules and the reference substance urea.

Novel chiral Schiff base Palladium(II), Nickel(II), Copper(II) and Iron(II) complexes: Synthesis, characterization, anticancer activity and molecular docking studies.

In this study, two chiral Schiff base ligands (L1 and L2) were synthesized from the condensation reaction of (S)-2-amino-3-phenyl-1-propanol with 2-hydroxybenzaldehyde and 2-hydroxy-1-naphthaldehyde as metal precursors for the preparation of transition metal complexes with Pd(II), Fe(II), Ni(II) and Cu(II). The compounds were characterized by using X-ray (for L1-Pd(II)), NMR, FT-IR, UV-Vis, magnetic susceptibility, molar conductivity, and elemental analysis. The in vitro cytotoxic effects of ligands (L1 and L2) and their metal complexes on colon cancer cells (DLD-1), breast cancer cells (MDA-MB-231) and healthy lung human cell lines were investigated by using the 3-(4,5-dimethylthiazol-2-yl)-2,5­diphenyl tetrazolium bromide (MTT) assay. Among the synthesized compounds, L1-Pd(II) was particularly found to be the most potent anticancer drug candidate in this series with IC50 values of 4.07, and 9.97 µM in DLD-1 and MDA-MB-231 cell lines, respectively. In addition, molecular docking results indicate that Glu122, Asn103, Ala104, Lys126, Phe114, Leu123, and Lys126 amino acids are the binding site of the colon cancer antigen protein, in which the most active complex, L1-Pd(II) can inhibit the current target.