Synthesis and characterization of MoS2-COOH/gly/Mn nanocomposite as an efficient adsorbent for Ultra-trace determination of trifluralin herbicide.

The world is confronting a severe water crisis. To clean up water from heavy metals, microorganisms, chemicals, and other types of pollutants, nanocomposites have been receiving great attention specifically due to the high surface area affording to work effectually even at low concentrations. In this research, we synthesized a new amino acid-modified MoS2 nanocomposite by chemically immobilizing Mn (II). The synthesized absorbent MoS2-COOH/gly/Mn was identified by thermogravimetric analysis (TGA), nitrogen adsorption measurement, X-ray diffraction (XRD), analysis of energy dispersive X-ray mapping (EDAX and MAP), field emission scanning electron microscopy (FE-SEM), and Fourier Transform Infrared spectrometry (FT-IR). The nanocomposite was employed as an adsorbent through the solid phase microextraction (SPME) method while trifluralin herbicide was chosen as a model compound. For the monitoring of trifluralin molecules, we employed an ion mobility spectrometry apparatus featuring a corona discharge ionization source. The SPME method's effectiveness was examined by investigating the stirring rate and extraction time as two crucial parameters, aiming to achieve trace analysis of trifluralin. Under the optimized condition of the trifluralin extraction, the coefficient (R2) and linear dynamic range (LDR) correlation were obtained at 0.9961 and 0.5-10 µg L-1, respectively. Relative recovery values the described approach were obtained in the span of 96-97% for agricultural wastewater samples. The quantification (LOQ) and limit of detection (LOD) were calculated at 0.5 and 0.15 µg L-1, respectively. The proposed nanocomposite absorbent has the capability to be applied as an efficient material for the extraction of trifluralin herbicide from different solutions.

Correction: In vitro and in vivo antiproliferative activity of organo-nickel SCS-pincer complexes on estrogen responsive MCF7 and MC4L2 breast cancer cells. Effects of amine fragment substitutions on BSA binding and cytotoxicity.

Correction for 'In vitro and in vivo antiproliferative activity of organo-nickel SCS-pincer complexes on estrogen responsive MCF7 and MC4L2 breast cancer cells. Effects of amine fragment substitutions on BSA binding and cytotoxicity' by Mahboubeh Hosseini-Kharat et al., Dalton Trans., 2018, 47, 16944-16957, https://doi.org/10.1039/c8dt03079k.

Novel P,C-orthopalladated complexes containing histidine and phenylalanine amino acids: synthesis, DNA and BSA interactions, in vitro antitumoral activity and molecular docking approach.

Novel [Pd(o-CH2C6H4P(o-tolyl)2)(histidine)] (1) and [Pd(o-CH2C6H4P(o tolyl)2)(phenylalanine)] (2) P,C-orthopalladated complexes have been prepared and characterized by elemental analysis, IR and NMR spectroscopy. To study the stability of the compounds in biological media, the complexes were incubated in Tris buffer during 10 days. The absorbance of the compounds remained constant, which confirmed the stability of the complexes in biological media. UV-Vis absorption spectrophotometry, fluorescence spectroscopy and viscosity studies were used to investigate the binding of the complexes with native calf thymus DNA (CT-DNA). These methods along with competitive binding of methylene blue (MB) DNA show that the complexes interact with DNA via groove mode. The UV-Vis absorption spectrophotometry of BSA with complexes has shown an α-helix perturbation induced by a particular interaction between the metal complexes and BSA. In addition, the fluorescence quenching mechanism of BSA with the complexes is a static process, according to the fluorescence spectrometry of bovine serum albumin (BSA). The experimental results of site competitive replacement with specific site markers are clear indications that the complexes bind to site I of BSA. Furthermore, both complexes showed significant selective cytotoxic activity against melanoma B16F0 and colon carcinoma C26 cancer cells as well as normal fibroblast NIH cell line. Ultimately, the binding of Pd(II) complexes to DNA and BSA was verified by molecular docking experiment.Communicated by Ramaswamy H. Sarma.

Experimental and theoretical studies of Palladium-hydrazide complexes' interaction with DNA and BSA, in vitro cytotoxicity activity and plasmid cleavage ability.

New palladium complexes with general formula trans-[Pd(L)2(OAc)2] (1,2), (L = Benzhydrazide and 2-Furoic hydrazide) have been synthesized and characterized with various methods including elemental analysis, FT-IR, 1HNMR and mass spectroscopy. Afterward their interactions with bovine serum albumin and calf thymus deoxyribonucleic acid have been investigated by UV-vis absorption, fluorescence emission and circular dichroism spectroscopy. Also, site-selective replacement experiments with site probes have been carried out. Analysis of fluorescence spectrum indicated static quenching mechanism. Spectroscopic measurements for DNA binding showed the groove binding to DNA for both complexes. Furthermore, cytotoxicity studies of complexes and cis-platin have been done against colon carcinoma (CT26) and breast cancer (4T1) cell lines. Evaluation of complexes (1) and (2) on induction of apoptosis in CT26 cells has been done. Finally, plasmid cleavage ability of (1) and (2) was investigated by gel electrophoresis that indicate the more activity of (1) than (2).

Potent cyclometallated Pd(II) antitumor complexes bearing α-amino acids: synthesis, structural characterization, DNA/BSA binding, cytotoxicity and molecular dynamics simulation.

A rational approach was adopted to design high-potential metal-based antitumor agents. A series of organometallic Pd(ii) complexes with a general formula of [Pd{κ2(C,C)-[(C6H4-2)PPh2]CH(CO)C6H4Ph-4}{κ2(N,O)}] (N,O = alanine (Pd-A), valine (Pd-V), leucine (Pd-L), l-isoleucine (Pd-I) and phenylalanine (Pd-F)) were prepared by cyclopalladation of the phosphorus ylide, bridge cleavage reaction and subsequent chelation of natural α-amino acids. The complexes were fully identified using IR and multinuclear 1H, 13C, 31P NMR spectroscopic methods. X-ray crystallography exhibited that the Pd(ii) atom is located in a slightly distorted square-planar environment surrounded by C,C-orthometallated phosphorus ylide as well as NO-pendant amino acid functionality. In vitro cytotoxicity evaluation of new cyclometallated Pd(ii) complexes toward a human leukemia (K562) cancer cell line indicated promising results. The highest cytotoxic activity was discovered in the case of phenylalanine (CH2C6H5). IC50 values of this complex on a panel of human tumor cell lines representative of liver (HepG2), breast (SKBR-3), and ovarian (A2780-Resistance/Sensitive) cancers also indicated promising antitumor effects in comparison with standard cisplatin. The binding interaction ability of the phenylalanine-containing orthopalladated complex, as the most efficient compound, with calf-thymus deoxyribonucleic acid (CT-DNA) and bovine serum albumin (BSA) was investigated. UV-Vis spectroscopy, competitive emission titration, and circular dichroism (CD) techniques demonstrated the intercalative binding of the Pd(ii) complex with DNA. Molecular docking studies also fully agreed with the experimental data. Examination of the reactivity towards the protein BSA revealed that the static quenching mechanism of BSA intrinsic fluorescence by the Pd(ii) complex with a binding constant (Kb) of ∼105 is indicative of the high affinity of the complex. The competitive binding experiment using site markers with definite binding sites demonstrated that the hydrophobic cavities of site I (subdomain IIA) are responsible for the bimolecular interaction between protein BSA and the complex. Molecular docking studies effectively confirmed the significance of hydrophobic interactions in Pd(ii)-BSA binding. The results of this study could greatly contribute to exploring new potent metal-based anticancer drugs.

Synthesis of a highly fluorescent N,N-dimethyl benzylamine-palladium(II) curcuminate complex and its application for determination of trace amounts of water in organic solvents.

In this work a new highly fluorescent N,N-dimethyl benzylamine-palladium(II) yu complex was synthesized by the reaction of [Pd2 {(C,N-C6 H4 CH2 N(CH3 )2 }2 (µ-OAc)]2 ] with curcumin. The structure of the synthesized complex was characterized using Fourier transform infra-red (FT-IR) spectroscopy, 1 H nuclear magnetic resonance spectroscopy, and elemental analysis. Fluorescence quantum yield (ΦF ) values of the synthesized complex in dimethyl sulfoxide (DMSO), acetonitrile, ethanol, and methanol were 0.160, 0.104, 0.068, and 0.061, respectively. The fluorescence signal of the complex in the organic solvents was very sensitive to the water content of the organic solvent. The quenching effect of water was used to determine trace amounts of water in the heteroatom-containing organic solvents (ethanol, methanol, acetonitrile) and redox-active solvents (DMSO). The linear ranges for determination of water (v/v %) in ethanol, DMSO and acetonitrile were found to be 0.03-14.5, 0.08-13.8, and 0.07-18.8, respectively. Two linear ranges were found for determination of water (v/v %) in methanol (0.1-1.2 and 4.7-25.0). Detection limit (DL) values were calculated to be 0.001, 0.05, 0.004, and 0.01 (v/v %) in ethanol, methanol, acetonitrile, and DMSO, respectively. The proposed method overcomes the problems of the standard Karl Fischer method for determination of water in DMSO. In addition, it gave the best DL value for determination of water in ethanol compared with all published papers to date.

Novel Palladium Complex: Cytotoxicity against Cisplatin-resistant K562 Cells.

Today, development of resistance to anticancer drugs (including cisplatin) is noticed as a major problem. Recently several studies demonstrated that palladium complexes showed remarkable cytotoxic effects against K562 cell line and could be used efficiently for treatment of many human cancers including leukemia. Hereof, K562 cells were made resistant to cisplatin using increasing concentration of cisplatin up to 4.5 mM and then cytotoxic effect of synthesized palladium complex was evaluated on this sub-line using MTT assay. Annexin V/PI staining using flow cytometry and scanning electron microscopy (SEM) were performed to find out the mechanism of the observed cytotoxicity. Results indicated that tested compounds had a noticeable cytotoxic effect on K562 cells 80 times more than cisplatin. Palladium complex also showed significant cytotoxicity on resistant K562 sub-line. Flow cytometry and SEM results revealed that these compounds exert their cytotoxic effect via apoptosis and it could be concluded that the novel synthesized palladium complex might be a good candidate for replacing cisplatin in case of treatment of cisplatin resistant tumors.

DNA G-quadruplexes binding and antitumor activity of palladium aryl oxime ligand complexes encapsulated in either albumin or algal cellulose nanoparticles.

The interactions between two Pd complexes, designated as [Pd3(C,N-(C6H4C(Cl) = NO)-4)6] (complex 1) and [Pd3(C12H8C = NO)6] (complex 2), with the human telomeric G-quadruplex DNA, 5'-G3(T2AG3)3-3' (HTG21), were monitored using spectroscopic, biological, and molecular modeling studies. According to the UV-vis results, these complexes can strongly induce and stabilize G-quadruplex DNA structure with Kb1 = 4.5(±0.3) × 106 M-1 and Kb2 = 1.0(±0.2) × 107 M-1via groove mode in comparison with duplex DNA. The release mechanism of the Pd complexes from BSA nanoparticles followed a biphasic pattern unlike that of algal cellulose nanoparticles in vitro. In addition, the cytotoxicity of these complexes on MCF-7 cancer cells and PBMC normal cells was evaluated and compared with cisplatin under similar experimental conditions. Furthermore, to determine and verify the interaction mode of these compounds with G-quadruplex, the molecular docking technique was also performed. Our data clearly demonstrated that complex 2 had higher activity and cytotoxicity than that of complex 1 and could be further investigated in the future as a drug discovery platform.

In vitro and in vivo antiproliferative activity of organo-nickel SCS-pincer complexes on estrogen responsive MCF7 and MC4L2 breast cancer cells. Effects of amine fragment substitutions on BSA binding and cytotoxicity.

A family of organonickel complexes has been prepared, fully characterized, and tested for their antiproliferative activity against estrogen-responsive human breast cancer cells (MCF7). The three SCS-type pincer ligands HL1, HL2, and HL3 and their corresponding Ni(ii) complexes NiL1, NiL2, and NiL3 have been synthesized and fully characterized, including by single crystal diffraction studies for the complexes. The complexes possess square planar geometry with two symmetrical 5-membered nickellacycles. Fluorescence spectroscopy, circular dichroism measurements, molecular modeling, colorimetric based assay and tumor transplantation studies were used to evaluate the protein binding and antiproliferative activities of these organometallic complexes both in vitro and in vivo. Fluorescence quenching was used to investigate bovine serum albumin (BSA) interaction at different temperatures (293, 303 and 313 K), and the results were analyzed using the classical Stern-Volmer equation, allowing us to propose a dynamic quenching mechanism. Studies in vitro on the antiproliferative activity of the three organonickel complexes against estrogen-responsive human breast cancer cells (MCF7) showed promising antitumor activity for NiL1 containing pyrrolidine fragments. In vivo administration of this compound significantly inhibits tumor growth in estrogen-dependent MC4L2 cancer cells in female BALB/c mice.

A palladium complex immobilized onto a magnetic GO-MnFe2O4 surface as an effective and recyclable catalyst for the reduction of p-nitrophenol.

A magnetically separable palladium complex on a GO-MnFe2O4 surface has been synthesized by covalent immobilization of a palladium complex on the magnetic GO-MnFe2O4 surface functionalized with 3-aminopropyltriethoxysilane (APTES). In general, magnetic, iron based materials (MnFe2O4) are effective in many catalytic reactions and are advantageous compared with other metal oxides due to their magnetic recyclability. The catalytic activities of these nanohybrids have been studied in p-nitrophenol (p-Nip) reduction. Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), inductively coupled plasma atomic emission spectrometry (ICP-AES), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDAX) and transmission electron microscopy (TEM) were used to characterize the catalyst. The successful incorporation of the palladium complex onto GO-MnFe2O4 has been confirmed by FT-IR spectroscopy, thermogravimetric analysis and ICP-AES. The intact structure of GO-MnFe2O4 was verified by X-ray diffraction (XRD), energy dispersive X-ray analysis (EDAX) and TEM. The strong reduction of p-nitrophenol was shown by the palladium complex on GO-MnFe2O4. This magnetic heterogeneous catalyst was well recoverable with no significant loss of activity and selectivity after five successive runs.

Folate receptor-targeted multimodal fluorescence mesosilica nanoparticles for imaging, delivery palladium complex and in vitro G-quadruplex DNA interaction.

New folic acid-conjugated mesoporous silica nanoparticles were synthesized. The effect of calcination at 400°C on the fluorescence characteristics of mesoporous silica nanoparticles were studied in this work. The formed carbon dots (CDs) from calcination were used as the source of fluorescence. 3-Aminopropyltriethoxysilane was then used to amine-functionalized the fluorescent surface of mesoporous silica nanoparticles. The amine fluorescence mesoporous silica nanoparticles (amine-FMSNs) were coupled with folic acid (FA) as the target ligand (FA-amine-FMSNs). A palladium complex was also synthesized and encapsulated in the FA-amine-FMSNs yielded fluorescent property with therapeutic effect. The in vitro release of an entrapped palladium complex from FA-amine-FMSNs was studied under physiological conditions. According to the cell viability assay on HeLa (positive FR) and Hep-G2 (negative FR) cells, the targeted delivery system inhibited the growth of positive FR with higher selectivity compared with negative FR cells. Also, the emission CDs were used for fluorescence microscopic imaging. To confirm anti-cancer activity of the palladium complex, the interaction between palladium complex and G-quadruplex DNA were investigated with multi-spectroscopic methods and molecular modeling. The molecular docking studies showed a partial intercalation mode with a 4.27 × 105 M-1 binding constant.

Synthesis and spectroscopic characterization study of new palladium complexes containing bioactive O,O-chelated ligands: evaluation of the DNA/protein BSA interaction, in vitro antitumoural activity and molecular docking.

[Pd{(C,N)-C6H4CH2NH(Et) (Qu)] (2) and [Pd{(C,N)-C6H4CH2NH(Et) (Nar)] (3) (Qu = Quercetin, Nar = Naringin) mononuclear palladium (II) complexes have been synthesized and characterized using elemental analysis, IR and electronic spectroscopy. The interaction of the prepared complexes with calf thymus DNA and bovine serum albumin (BSA), monitored by UV-visible and fluorescence titrations, respectively, have been carried out to better understand the mode of their action under biological conditions. Intercalative binding mode between the complexes and DNA is suggested by the binding constant (Kb) values of 2.5 × 106 and 3.2 × 106 for complexes 2 and 3, respectively. In particular, the in vitro cytotoxicity of the complexes on two cancer cells lines (bladder carcinoma TCC and breast cancer MCF7) showed that the compounds had broad spectrum, anti-cancer activity with low IC50 values and the order of in vitro anticancer activities is consistent with the DNA-binding affinities. In the meantime, the quenching of tryptophan emission with the addition of complexes using BSA as a model protein indicated the protein binding ability. The quenching mechanisms of BSA by the complexes were static processes, according to the results obtained. The competitive binding using Warfarin, Digoxin and Ibuprofen site markers, which contain definite biding sites, demonstrated that the complexes bind to site I on BSA. Ultimately, the binding sites of DNA and BSA with the complexes have been determined by molecular modelling studies.

Synthesis, spectral characterization, crystal structure and in vitro DNA/protein binding studies of phosphorous ylide palladacyclic complexes containing azide group.

The reaction between (4-nitrobenzoylmethylene)triphenylphosphorane Pd(II) complex [Pd{κ(2)(C,C)-C6 H4PPh2C(H)CO(C6 H4NO2-4)}(µ-Cl)]2 and excess of NaN3 resulted in the µ-N3 bridged Pd(II) complex [Pd{κ(2)(C,C)-C6H4PPh2C(H)CO(C6 H4NO2-4)}(µ-N3)]2 (1), which underwent bridge cleavage reactions with monodentate ligands to afford the monomeric, neutral complexes [Pd{κ(2)(C,C)-C6 H4PPh2C(H)CO(C6 H4NO2-4)}N3(L)] (L=Me3Py (1a), PPh3 (1b)). The complexes were identified and characterized by elemental analyses, infrared (IR), ((1))H, ((13))C{((1))H} and ((31))P{((1))H} NMR spectroscopy. The molecular structure of 1b was determined by single-crystal X-ray diffraction. The interactions of complexes with FS-DNA were investigated using UV absorption and fluorescence spectra. The results suggested that both complexes could interact with FS-DNA through the intercalation mode and follow the binding affinity order of 1a>1b. The reactivity toward protein BSA revealed that the quenching of BSA fluorescence by the two complexes are static quenching, and complex 1a exhibits a higher BSA-binding ability than the complex 1b.

In vitro cytotoxicity studies of palladacyclic complexes containing the symmetric diphosphine bridging ligand. Studies of their interactions with DNA and BSA.

The reactions between [Pd2{(C,N)-C6H4CH2NH(Et)}2(µ-X)2] (X = Cl or Br) and 1,2-bis(diphenylphosphino)ethane (dppe) in the 1:1 molar ratio resulted in the dppe-bridged Pd(II) complexes, [Pd2{(C,N)-C6H4CH2NH(Et)}2(µ-dppe)(Cl)2] (1) and [Pd2{(C,N)-C6H4CH2NH(Et)}2(µ-dppe)(Br)2] (2), respectively, which were characterized by elemental analyses, infrared (IR), (1)H- and (31)P{(1)H} NMR spectroscopy. The molecular structure of 1 was determined by single-crystal X-ray diffraction. In vitro cytotoxicity of 1, 2, dppe, PhCH2NH(Et) and cisplatin were carried out against four human tumor cell lines. The interactions of complexes towards DNA and protein are investigated. The results suggested that both complexes could interact with FS-DNA through the intercalation mode. Moreover, the reactivity towards BSA revealed that the microenvironment and the secondary structure of BSA were changed in the presence of Pd(II) complexes.

[1,2-Bis(diphenyl-phosphan-yl)ethane-κP,P']{2-[(4-nitro-benzoyl-meth-yl)diphenyl-phosphan-yl]phenyl-κC,C'}palladium(II) trifluoro-methane-sulfonate-dichloro-methane-n-hexane (1/1/0.5).

In the cation of the title compound, [Pd(C(26)H(19)NO(3)P)(C(26)H(24)P(2))]CF(3)O(3)S·CH(2)Cl(2)·0.5C(6)H(14), the Pd(II) atom has a slightly tetra-hedrally distorted square-planar coordination geometry. The PdC(3)P and PdC(2)P(2) five-membered metallacycles adopt envelope and twist conformations, respectively. In the crystal, inter-molecular C-H⋯O hydrogen bonds link cations and anions into a three-dimensional network. The dichloro-methane solvent mol-ecule is disordered over three orientations with a site-occupancy ratio of 0.5/0.3/0.2. The n-hexane solvent mol-ecule has a crystallographically imposed centre of symmetry.

Triphen-yl[(4-phenyl-benzo-yl)meth-yl]phospho-nium trifluoro-methane-sulfonate.

In the cation of the title compound, C(32)H(26)OP(+)·CF(3)O(3)S(-), the dihedral angle between the benzene rings of the biphenyl group is 42.37 (8)°. In the crystal, the cations and anions inter-act through inter-molecular C-H⋯O hydrogen bonds, forming chains parallel to the b axis. These chains are further linked by C-H⋯π stacking inter-actions into layers parallel to the bc plane.

Synthesis and characterization of new Pd(II) complexes of L-ethylphenylalanate.

Complex (S,S)-[Pd{C(6)H(4)(CH(2)CHNH(2)CO(2)CH(2)CH(3))}(mu-Br)](2) (3) was prepared following the method by Vicente and Saura-Llamas (Organometallics 26:2768-2776, 2007), by the reaction of L: -ethylphenylalanate and Pd(OAc)(2) in 1:1 molar ratio under acetonitrile heating conditions and subsequently treating with NaBr. In addition, the cleavage of halogeno-bridge of the complex 3 via nucleophilic attack of some neutral ligands such as triphenylphosphine, pyridine, 2,4,6-trimethylpyridine and piperidine were investigated and the corresponding complexes (S)-[Pd{C(6)H(4)(CH(2)CHNH(2)CO(2)CH(2)CH(3))(Y)(Br)}] (4a-f) were obtained in moderate yields. The six-member orthopalladated complexes were characterized by (1)H-NMR, (31)P-NMR, FT-IR and elemental analysis techniques.

(4-Methoxy-benzoyl-meth-yl)triphenyl-phospho-nium trifluoro-methane-sulfonate.

Colourless crystals of the title compound, C(27)H(24)O(2)P(+)·CF(3)SO(3) (-), have been prepared by the addition of a solution of AgCF(3)SO(3) in methanol to a solution of (4-methoxy-benzoyl-meth-yl)triphenyl-phospho-nium bromide in dry methanol. There are two crystallographically independent mol-ecules in the asymmetric unit. The crystal structure is stabilized by inter- and intra-molecular C-H⋯O hydrogen bonds and further stabilized by C-H⋯π inter-actions.

Di-µ-iodido-bis-{[(4-fluoro-benzoyl-methyl-ene)triphenyl-λ-phospho-rane]iodido-mercury(II)}.

In the title complex, [Hg(2)I(4)(C(26)H(20)FOP)(2)], the Hg(II) centre is four-coordinate with one short Hg-I bond [2.6895 (7) Å], one Hg-C bond and two asymmetric bridging Hg-I bonds with distances of 2.7780 (8) and 3.2599 (8) Å. The title mol-ecule has a crystallographic inversion centre at the centroid of the four-membered ring formed by the two Hg atoms and two I atoms. The crystal packing is stabilized by C-H⋯O hydrogen bonds.