Visible light-driven photocatalysts, quantum chemical calculations, ADMET-SAR parameters, and DNA binding studies of nickel complex of sulfadiazine.

A 3D-supramolecular nickel integrated Ni-SDZ complex was synthesized using sodium salt of sulfadiazine as the ligand and nickel(II) acetate as the metal salt using a condensation process and slow evaporation approach to growing the single crystal. The metal complex was characterized for its composition, functional groups, surface morphology as well as complex 3D structure, by resorting to various analytical techniques. The interacting surface and stability as well as reactivity of the complex were carried out using the DFT platform. From ADMET parameters, human Intestinal Absorbance data revealed that the compound has the potential to be well absorbed, and also Ni-SDZ complex cannot cross the blood-brain barrier (BBB). Additionally, the complex's DNA binding affinity and in-vivo and in-vitro cytotoxic studies were explored utilizing UV-Vis absorbance titration, viscosity measurements, and S. pombe cells and brine shrimp lethality tests. In visible light radiation, the Ni-SDZ complex displayed exceptional photo-degradation characteristics of approximately 70.19% within 70 min against methylene blue (MB).

1-D MOF [Ag2(C10H10N3O3S)2(C4H8N)2]n: photocatalytic treatment, crystallographic evaluation, ADMET parameters, CT-DNA and anticancer activity.

Newly synthesized dinuclear crystalline polymer, the silver complex of bidentate Sulfamethoxazole (Ag-SMX) in the presence of secondary ligand pyrrolidine has been characterized by elemental, spectral (1H-NMR spectra, FT-IR spectra, UV-Vis spectra.), powder XRD, and single-crystal X-ray diffraction (single-crystal) analysis. The synthesis molecular structure of the dinuclear [Ag2(C10H10N3O3S)2(C4H8N)2]n complex reveals a one-dimensional polymeric chain with seesaw geometry (τ4 = 0.71): two silvers interlink each other by argentophilic interaction with Ag1…Ag2 separation distance of 3.0047(6) Å. The Hirshfeld surfaces (HS) and 2D fingerprint plots were used to examine the interconnects in the crystal packing. Molecule properties including MEP, MPA, HOMO-LUMO energy, and global reactivity descriptor parameters were computed to understand the molecule's stability. From ADMET parameters, human Intestinal Absorbance data revealed that the compound has the potential to be well absorbed, and also Ag-smx complex cannot cross the blood-brain barrier (BBB). The capacity of the silver complex to interact with CtDNA was investigated using absorption spectroscopy and viscosity tests. The interaction between CT-DNA reveals that the Ag-SMX complex exhibits the strongest binding affinity among all known sulfonamide derivatives and their metal complexes. The silver complex has higher inhibitory action than the free SMX ligand, according to data from a panel of gram (+ve) and gram (-ve) organisms' minimum inhibitory concentrations. In vitro cytotoxicity investigation revealed that the IC50 value for Ag-SMX is 57.12 g/mL and for SMX is 100.90 g/mL against human lung cancer cell line (A549). This study revealed that, when compared to SMX free-ligand, Ag-SMX is the most effective in terms of cytotoxicity toward the human lung cancer cell line (A549 cell line). In under 120 min, the synthesized Ag-smx complex showed exceptional photo-degradation characteristics against methylene blue (MB) (10 ppm) in visible light radiation.Communicated by Ramaswamy H. Sarma.

Synthetic approach toward spiro quinoxaline-ß-lactam based heterocyclic compounds: Spectral characterization, SAR, pharmacokinetic and biomolecular interaction studies.

Series of spiro quinoxaline-ß-lactam based heterocyclic compounds (QL 1 - QL 21) were synthesized and characterized by spectroscopic techniques like 1H-NMR, LC-MS, FT-IR spectroscopy and elemental analysis. The binding mode and binding strength between compounds and calf thymus-DNA were estimated by UV-visible spectroscopy, viscosity measurement and molecular docking studies. The compounds bind with the DNA through partial intercalation mode. In the absorption titration experiment, the Kb values for all the synthesized compounds were found in the range of 0.24-0.64 × 105 M-1. The protein binding studies of all the synthesized compounds were evaluated by absorption titration experiment, and the Kb value for all the compounds was obtained in the range of 0.030-1.571 × 104 M-1. The compounds were screened against two Gram (+ve) and three Gram (-ve) bacteria for antimicrobial activity. The MIC values for all the synthesized compounds were found in 95-255 µM. The LC50 values (cytotoxicity) of the synthesized compounds (QL 1-QL 21) were found in the range of 4.00-12.89 µg/mL. The ADME study was carried out using the online platform SwissADME and admetSAR to evaluate the pharmacokinetic profile of all the synthesized compounds. All the compounds were screened for anticancer activity against the human osteosarcoma (MG-63) cell line. The result shows that all the compounds exhibit effective anticancer activity.Communicated by Ramaswamy H. Sarma.

Mechanistic insight of cell anti-proliferative activity of fluoroquinolone drug-based Cu(II) complexes.

Pefloxacin-based mixed ligand Cu(II) complexes with substituted isatin of type [Cu(Isatin)(Pefloxacin)Cl] were synthesized, and characterized by EPR, mass, FT-IR, electronic spectrometry, metal content, magnetic moment, and conductance measurement. The g factors g [Formula: see text] > g [Formula: see text] > 2.0023 observed in EPR suggest a square-pyramidal environment of ligands around the copper metal. The compounds were screened for diverse biological activities. The compounds inhibit efficiently the cell proliferation of HCT 116 cancer cells. To take the insight of anticancer activity mechanism, we investigated compound-1 for further cellular assay-based biological activities like trypan blue assay, cell morphological alteration assay, colony formation assay, cell apoptosis, and cell necrosis assay. The compound-1 induced distinct morphological alteration in cells, inhibits cell viability, decreases % plating efficiency, and decreases the clonogenic ability of the HCT 116 cells. The cell death mechanism was confirmed by annexin V-FITC / PI assay and LDH release assay. The positive annexin V/PI stained cells in presence of compound-1 and the absence of a significant amount of lactate dehydrogenase suggest cell apoptosis mechanism for anticancer activity of compounds. We also screened compounds for in vitro antibacterial and cytotoxic activities. Synthesis, characterization, antibacterial, anticancer, and cytotoxicity activities of pefloxacin based Cu(II) complexes were studied. The compound -1 is more potent than standard anticancer drugs and it induced apoptosis to the HCT 116 cells.

DNA interaction, anticancer, cytotoxicity and genotoxicity studies with potential pyrazine-bipyrazole dinuclear µ-oxo bridged Au(III) complexes.

Pyrazine-bipyrazole-based µ-oxo bridged dinuclear Au(III) complexes were synthesized and characterized by various spectrometric (1H-NMR, 13C (APT) NMR, FT-IR, Mass spectrometry) and analytical techniques (elemental analysis and conductance measurement). The evaluation of DNA binding activity by UV-Vis absorption spectra and viscosity measurement demonstrated that all the compounds intercalate in between the stacks of DNA base pair and the binding constant values were observed in the range of 5.4 × 104-2.17 × 105 M-1. The molecular docking study also supports the intercalation mode of binding. The anti-proliferation activity of complexes on A549 (Lung adenocarcinoma) cells by MTT assay demonstrated IC50 values in the range of 47.46 -298.12 µg/mL. The genotoxicity of compounds was checked by smearing observed in the DNA of S. pombe cell under the influence of complexes. The in vivo cytotoxicity of compounds against brine shrimp demonstrated the LC50 values in the range of 4.59-27.22 µg/mL. The promising results of the Au(III) complexes received significant attention and make them suitable for the new metallodrugs after the detailed mechanistic biological study.

Synthesis, characterization, and biological applications of pyrazole moiety bearing osmium(IV) complexes.

Osmium (IV) complexes with pyrazole nucleus containing ligands were synthesized. Os(IV) compounds were characterized using ESI-MS, ICP-OES, IR spectroscopy, electronic spectroscopy, conductance, and magnetic measurements. Whereas, ligands were characterized by heteronuclear spectroscopy, (1H and 13C), IR spectroscopy, and elemental analysis. All the compounds were tested for their potential to interact with HS-DNA by absorption titration, fluorescence spectroscopy, viscosity measurement, and docking study. The quenching constant and Stern Volmer constant values were calculated using fluorescence study. The synthesized compounds were studied for in-vitro bacteriostatic and cytotoxic activities. The cancer cell line studies of all the synthesized complexes were carried out on human lung cancer cells (A549).Supplemental data for this article is available online at https://doi.org/10.1080/15257770.2021.1921795 .

Fluorescence, DNA Interaction and Cytotoxicity Studies of 4,5-Dihydro-1H-Pyrazol-1-Yl Moiety Based Os(IV) Compounds: Synthesis, Characterization and Biological Evaluation.

Osmium(IV) pyrazole compounds and ligands were synthesized and well characterised. Ligands were characterized by heteronuclear NMR spectroscopy (1H & 13C), elemental analysis, IR spectroscopy and liquid crystal mass spectroscopy. Os(IV) complexes were characterized by ESI-MS, ICP-OES, IR spectroscopy, conductance measurements, magnetic measurements and electronic spectroscopy. Binding of compounds with HS-DNA were evaluated using viscosity measurements, absorption titration, fluorescence quenching, and molecular docking, which show effective intercalation mode exhibited by compounds. Binding constant of Os(IV) complexes are found to be 8.1 to 9.2 × 104 M-1. Bacteriostatic and cytotoxic activities were carried out to evaluate MIC, LC50, and IC50. The compounds have been undergone bacteriostatic screening using three sets of Gram+ve and two sets of Gram-ve bacteria. MIC of complexes are found to be 72.5-100 µM, whereas that of ligands fall at about 122.5-150 µM.. LC50 count of ligands fall in the range of 16.22-17.28 µg/mL whereas that of complexes of Os(IV) fall in the range of 4.87-5.87 µg/mL. IC50 of osmium compounds were evaluated using HCT-116 cell line. All the Os(IV) compounds show moderate IC50.

Cell apoptosis induced by ciprofloxacin based Cu(II) complexes: cytotoxicity, SOD mimic and antibacterial studies.

The current cancer research focuses on the design and synthesis of chemical compounds that can modulate cell apoptosis or programmed cell death. So we synthesized and characterized ciprofloxacin based copper(II) complexes and studied their anticancer activity against HCT 116 cancer cells by MTT assay. We further investigated the influence of compound-2 (better IC50 value than cisplatin) on cancer cells to know the exact mechanism of anticancer activity. The distinct morphological change of cells due to compound-2 was observed in bright field microscopy. The trypan blue assay clearly demonstrated inhibition of cell viability. The clonogenic ability inhibition assay showed a low percentage of the plating efficiency of HCT 116 cells. The mechanism of cell death, either apoptotic or necrotic was distinguished by annexin V-FITC/PI (propidium iodide) staining assay and LDH (lactate dehydrogenase) release assay. The positive annexinV/PI cells in presence of compound-2 and absence of LDH in the LDH release assay confirmed the cell apoptotic mechanism of cell death. We also checked in vitro antibacterial activity of compounds against Gram(-ve) and Gram(+ve) bacteria in terms of MIC (minimum inhibitory concentration) and the data were in good agreement with the standard drug data. SOD mimic activity of synthesized Cu(II) complexes was also studied in terms of IC50 value. The brine shrimp lethality bioassay was also performed to evaluate the cytotoxic properties of the Cu(II) complexes.Communicated by Ramaswamy H. Sarma.

Tetrazolo[1,5-a]quinoline moiety-based Os(IV) complexes: DNA binding/cleavage, bacteriostatic and photocytotoxicity assay.

Biological applications of platinum group metal-based complexes have been widely explored in synthetic and inorganic chemistry. The compounds have been subjected to DNA binding, DNA cleavage, In-vivo and In-vitro photocytotoxicity (HCT-116 cell line) and bacteriostatic activities. Binding constant of complexes are 1.42-5.62 × 104 M-1, whereas that of ligands are 1.12-4.72 × 104 M-1. Ksv of complexes are about 1.32-5.21 × 103 M-1, whereas Kf is about 1.24-6.83 × 103 M-1. IC50 of compounds screened using HCT-116 cell line in dark are found to be 121-342 µg/mL. Whereas photocytotoxicity is found in the range of 48-316 µg/mL. Docking energy of molecules have been evaluated to evaluate efficacy of binding. Molecular docking energy of complexes are in the range of -286.00 to -303.11 kJ/mol. Whereas that of ligands are -254.03 to -282.96 kJ/mol. MIC of complexes are 47 ± 2.5 to 77.50 ± 7.5 µM. LC50 values of ligands fall in the range of 4.05-19.72 µg/mL and that of Os(IV) complexes fall in the range of 3.99-15.99 µg/mL. The Os(IV) complexes dominate in proving its potentiality compared to N, N-donor ligands in biological activities. [Formula: see text]Communicated by Ramaswamy H. Sarma.

Biological activities of pyrazoline-indole based Re(I) carbonyls: DNA interaction, antibacterial, anticancer, ROS production, lipid peroxidation, in vivo and in vitro cytotoxicity studies.

Hetero mononuclear rhenium(I) metal complexes (I-V) using different substituted indole-pyrazoline based ligands were synthesized and characterized by spectroscopic and analytical methods. The binding of the rhenium complexes to Herring sperm DNA was monitored by UV spectroscopy, viscosity measurements, and molecular docking studies; groove binding was suggested as the most possible mode and the DNA-binding constants of the complexes were evaluated. In vivo and in vitro cytotoxicity of compounds were evaluated against the brine shrimp and S. cerevisiae cells. An antimicrobial study was carried out by estimating MIC (Minimum Inhibitory Concentration) against two Gram-positive and three Gram-negative bacteria. All synthesized complexes are biologically more active than the corresponding ligands. The anti-proliferation activity of complexes was evaluated on MCF-7, HCT116, and A549 cancer cells by MTT assay. The toxicity profile of synthesized compounds was confirmed by H2O2 production by reactive oxygen species. The increased concentration of lipid peroxidation end products increased free radicals, which enhancing the oxidative stress level in living organisms and results in cell death.

Synthesis, Characterization and Biological Application of Pyrazolo[1,5-a]pyrimidine Based Organometallic Re(I) Complexes.

The neutral rhenium(I) complexes (I-VI) of type [ReCl(CO)3Ln-] where L1 = 7-phenyl-5-(pyridin-2-yl)pyrazolo[1,5-a]pyrimidine, L2 = 7-(4-bromophenyl)-5-(pyridin-2-yl)pyrazolo[1,5-a]pyrimi- dine, L3 = 7-(4-chlorophenyl)-5-(pyridin-2-yl)pyrazolo[1,5-a]pyrimidine, L4 = 7-(2-chlorophenyl) -5-(pyridin-2-yl)pyrazolo[1,5-a]pyrimidine, L5 = 7-(4-methoxyphenyl)-5-(pyridin-2-yl)pyrazolo [1,5-a]pyrimidine, L6 = 5-(pyridin-2-yl)-7-(p-tolyl)pyrazolo[1,5-a]pyrimidine were synthesized and characterized by 13C-APT, 1H-NMR, IR, electronic spectra, magnetic moment and conductance measurement. The anti-proliferative activity on HCT116 cells by MTT assay suggests potent cytotoxic nature of complexes, even some complexes have better activity than standard drug cisplatin, oxaliplatin, and carboplatin. The complexes found to have better antimicrobial activity compare to pyrazolo pyrimidine ligands. The theoretical study of compounds-DNA interactions was examined by molecular docking as a supportive tool to the experimental data, which suggests the groove mode of binding. The values of docking energy for compounds-DNA interaction were found in the range of -230.31 to -288.34 kJ/mol. The intrinsic binding constant values of complexes (1.1-3.5×105 M-1) were found higher than the ligands (0.32-1.8×105 M-1).

Synthesis, characterization and biological activities of imidazo[1,2-a]pyridine based gold(III) metal complexes.

Five imidazo [1,2-a]pyridine derivatives and their Au(III) complexes were synthesized. The compounds were characterized by 1H-NMR, 13C-NMR, IR, mass, UV-visible, elemental analysis, conductivity and magnetic measurement studies. All the compounds were screened for diverse biological activities to check the effect of coordination of Au(III) with imidazo [1,2-a]pyridine heterocycles. The DNA interaction ability of compounds were studied as the change in absorption maxima and position of HS-DNA in presence of compounds and viscosity measurement due to change in DNA length under the influence of compounds. The computational insight of compound-DNA interaction was taken in docking study. All the results suggest intercalation mode of binding. The cellular level cytotoxic nature of compounds was evaluated using trypan blue dye staining of dead cell in cell viability assay. The smearing of DNA was observed, while DNA extracted from S. pombe cells in presence of complexes was subjected to gel electrophoresis, which shows their toxic effect on DNA. The complexes were evaluated for cytotoxicity on human A549 (Lung adenocarcinoma) cell line by MTT assay (IC50 values). The in vitro cytotoxicity in terms of LC50 value was checked on a simple zoological organism, brine shrimp.

Fluorescence and absorption studies of DNA-Pd(II) complex interaction: Synthesis, spectroanalytical investigations and biological activities.

Novel palladium(II) complexes (7a-7e) of substituted quinoline derivatives were synthesized. The complexes were characterized using various techniques such as thermogravimetric analysis (TGA), elemental analysis, conductance measurement, mass, absorption, infra-red (IR), 1 H NMR, 13 C NMR and energy-dispersive X-ray spectroscopy (EDX). Complexes for herring sperm DNA (HS DNA) binding were explored and absorption titration and the binding constant (Kb ) as well as Gibb's free energy were evaluated. Complex 7d exhibited the highest binding constant, therefore the thermodynamic parameters of 7d at different temperatures were evaluated. To support the results of the absorption titration, fluorescence titration, viscosity measurement and molecular docking studies were performed. The fluorescence quenching data as evaluated from Stern-Volmer equation were used to calculate KSV , Kf and the number of binding sites. The results of all these studies were in good agreement with the absorption study. DNA electrophoretic mobility was performed to explore the possible application of metal complexes as artificial metallonucleases. The antibacterial activity of the complexes was accessed against different pathogenic bacteria and cytotoxicity was measured using brine shrimp and S. pombe.

DNA Interaction, in vitro Antibacterial and Cytotoxic Activities of Ru(III) Heterochelates.

Ruthenium(III) complexes [Ru(bphtpy)(PPh3)Cl3] (bphfpy = diphenylfuranylpyridine derivatives) were synthesized and characterized by LCMS, IR spectroscopy, elemental analysis and magnetic measurements. All the complexes were screened for their antibacterial activity in terms of minimum inhibitory concentration against two Gram-positive and three Gram-negative bacterial species. DNA binding study by absorption titration and viscosity measurement shows that complexes bind in an intercalating mode, which is also confirmed by molecular docking. All the complexes were also screened for the DNA nuclease property of pUC19 plasmid DNA. The cytotoxicity study of the synthesized complexes was performed to elucidate the LC50 values to find out the toxicity profile of the complexes.

Half Sandwich Rhodium(III) and Iridium(III) Complexes as Cytotoxic and Metallonuclease Agents.

Half sandwich complexes of the type [(η5-C5Me5)M(L1-3)Cl]Cl.2H2O were synthesized using [{(η5-C5Me5)M(µ-Cl)Cl}2], where M = Rh(III)/Ir(III) and L1-3 = pyrimidine-based ligands. The complexes were characterized by spectral analysis. DNA interaction studies by absorption titration and hydrodynamic measurement and suggest intercalative mode of binding of complexes with CT-DNA. The molecular docking study also supports intercalation of the complexes between the stacks of nucleotide base pairs. The gel electrophoresis assay demonstrated the ability of the complexes to interact and cleave plasmid DNA. Minimum inhibitory concentrations (MIC) of the complexes were investigated by the microdilution broth method. The cytotoxic properties of the metal complexes were evaluated using brine shrimp lethality bioassay.

Synthesis and evaluation of gold(III) complexes as efficient DNA binders and cytotoxic agents.

In recent years, great interest has been focused on gold(III) complexes as cytotoxic and antitumor drugs. Recent studies demonstrated that simple bidentate or polydentate ligands containing nitrogen donor atoms may offer sufficient redox stabilization to produce viable Au(III) anticancer drug targets under physiologic conditions. So, we have synthesized square planer Au(III) complexes of type [Au(A(n))Clx]·Cly and characterized them using UV-Vis absorption, C, H, N elemental analysis, FT-IR, LC-MS, (1)H and (13)C NMR spectroscopy. These compounds manifested significant cytotoxic properties in vitro for brine shrimp lethality bioassay. The metal complexes were screened for series of DNA binding activity using UV-Vis absorption titration, hydrodynamic measurement and thermal DNA denaturation study. The nucleolytic activity was performed on plasmid pUC19 DNA. The Michaelis-Menten kinetic studies were performed to evaluate rate of enhancement in metal complexes mediated DNA cleavage over the non-catalyzed DNA cleavage.

Study of SOD mimic and nucleic acid interaction activity exerted by enrofloxacin-based copper(II) complexes.

Five new copper(II) complexes of type [Cu(erx)(L)Cl] (erx, enrofloxacin; thiophene-2-carbaldehyde (L(1) ); pyridine-2-carbaldehyde (L(2) ); 2,2'-dipyridylamine (L(3) ); 4,5-diazafluoren-9-one (L(4) ); bis(3,5-dimethyl-1-pyrazolyl)methane (L(5) )) have been synthesized and characterized by elemental analysis, reflectance, IR, and FAB-MS. Complexes have been investigated for their interaction with calf thymus (CT) DNA utilizing the absorption-titration method, viscometric and DNA thermal denaturation studies. The cleavage reaction on pUC19 DNA has been monitored by agarose gel electrophoresis. The results indicated that the Cu(II) complexes can more effectively promote the cleavage of plasmid DNA at physiological pH and superoxide dismutase. The (SOD) activity of the complexes has been evaluated by the nitroblue tetrazolium assay, and the complexes catalyzed the dismutation of superoxide at pH 7.8 with IC(50) values of 0.35-1.25 µM. The complexes have also been screened for their antibacterial activity against five pathogenic bacteria.

Topoisomerase inhibition, nucleolytic and electrolytic contribution on DNA binding activity exerted by biological active analogue of coordination compounds.

The neutral mononuclear copper complexes with the quinolone antibacterial drug ciprofloxacin and bipyridine derivatives have been synthesized and characterized. Complexes were screened for their antibacterial activity against three Gram((-)) and two Gram((+)) bacteria, and study suggests inhibition of gyrase activity by metal complexes as the possible mechanism. The nucleolytic activity of adducts was carried out on double stranded pUC19 DNA using gel electrophoresis in the presence of radical scavenging agents that suggest hydrolytic cleavage mechanism for plasmid DNA.

Synthesis, characterization and biological activities of ciprofloxacin drug based metal complexes.

The interaction of small molecules with DNA has attracted a great deal of attention. Mixed ligand copper(II) complexes of type [Cu(cpf)(Ln)Cl] [cpf = ciprofloxacin, Ln = phenanthroline derivatives] were synthesized and characterized by elemental analysis, reflectance, IR and mass spectra. Viscosity measurements, absorption titration and DNA melting temperature studies were employed to determine the mode of binding of complexes with DNA. DNA cleavage study showed better cleaving ability of the complexes compare to metal salts and standard drug. The SOD mimic study showed IC50 value of complexes in the range of 0.95 to 1.75 µM. Antibacterial activity was assayed against selective Gram(-ve) and Gram(+ve) microorganisms.

Nucleic acid interaction and antibacterial behaviours of a ternary palladium(II) complexes.

The bidentate ligands and Pd(II) complexes have been synthesized and characterized using elemental analysis (C, H, N), (1)H NMR, (13)C NMR, electronic spectra, FT-IR and FAB mass spectroscopy. The binding of palladium complexes with calf thymus DNA (CT DNA) has been explored using absorption titration, DNA melting temperature and viscosity measurements. The cleavage reaction on pUC19 DNA has been monitored by agarose gel electrophoresis. The results suggest that complexes can bind to DNA by intercalative modes and exhibit nuclease activities in which supercoil form is converted to open circular form. The antibacterial activity of ligands and complexes has been performed against three Gram(-ve) and two Gram(+ve) microorganisms and the study indicates that all the complexes show better microbial inhibition activity than ligands and palladium salt.