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• Synthesis of novel mononuclear and homodinuclear Ru(II) complexes. • Synthesis of novel mixed trinuclear Ru(II)/Ru(III) complex. • Sstructures elucidateion the by UV-Vis, Near InfraRed spectroscopy, NMR, ESI-Mass and cyclic voltammetry techniques. • Investigating phrancological performance of the complexes. • Performing molecular docking studies on the DNA-interaction with the complexs. Three new heteroleptic ruthenium(II) complexes with mixed ligands were prepared: [Ru(bpy) 2 (Cl 2 dpq)]Cl 2 (1), [Ru(bpy) 2 (Cl 2 dpq)Ru(bpy) 2 ]Cl 4 (2), and [Ru(bpy) 2 (Cl 2 dpq)RuCl 2 (Cl 2 dpq)Ru(bpy) 2 ]Cl 5 (3), in which Cl 2 dpq = 6,7-dichloro-2,3-di(pyridin-2-yl)quinoxaline; bpy = 2,2′-bipyridine. Various physicochemical tools were used to characterize the new complexes, such as elemental analysis, infrared, 1H-NMR and ESI-MS. The complexes were investigated for their Photochemical properties by studying their UV-Vis, luminescence, and NIR spectra. Additionally, cyclic voltammetry studies were performed to evaluate the electrochemical behavior of the complexes. Investigation of the new complexes' interaction with calf thymus DNA (CT-DNA) was carried out using various spectroscopic techniques and the experimental data were corroborated against molecular docking studies. Furthermore, the complexes' in vitro cytotoxicity against DPPH radicals and their scavenging effects against HeLa and MCF-7 cell lines were assessed. [Display omitted] [ABSTRACT FROM AUTHOR]

• Flexible π extension benefits the groove binding with DNA. • Both covalent and non-covalent interactions with DNA exist. • DNA pocket docking should consider the total electronic effect. • Crystal structure was highly overlapped with the DFT-optimized structure. • The "Off-On" character helps us to understand the tumor therapeutic target. Organometallic medicines based on ruthenium (Ru) have attracted interest as chemotherapeutic and bioimaging agents due to their low toxicity and superior physical optical characteristics. However, there are still no ideal candidates in clinical trials due to the lack of understanding of the structure-activity relationships (SARs) of polypyrodyl Ru(II) complexes. Though increasing the electron-donating ability of the ligands has been proven to benefit bioactivity due to the fast hydroxylation rate between chlorine and DNA, the total electronic effects are much more important, especially for the binding modes between Ru(II)-polypyridyl complexes and DNA. By evaluating the electron-donating ability of the ligand complexes 1 - 4 through density functional theory (DFT) calculations, bioactivities tests, and docking studies, we investigated the relationship between the structures of Ru(II) complexes and cytotoxicity. Our findings showed that it was insufficient to merely consider the impact of electron-donating effects on biological activities in place of interaction modes. Furthermore, the cellular imaging study investigated the complex with phenyl substituents (1) and confirmed that the main target was DNA. Besides, the "off-on" emission phenomena of complex 1 indicated that there is also covalent interaction with DNA. These findings offer valuable insight into the development of SARs of polypyrodyl Ru(II) complexes. The flexible π extension benefit the fits of Ru(II) complex adopted with DNA, which enhance the cytotoxicity of antitumor effects. [Display omitted] [ABSTRACT FROM AUTHOR]

• A tridentate schiff base ligand containing naphtyl moiety with general formula (N^N^OH) was synthesized. • Pt-L2 was obtained from the ligand with the formula [PtCl(N^N^O)]. • Changes in the relative viscosity of ct-DNA indicated an intercalation mode of binding for Pt-L2. • Pt-L2 indicated the spontaneous formation of an adduct with BSA with good binding affinity. • Pt-L2 possesses better IC 50 values compared to cisplatin against two cancer cell lines. A tridentate Schiff base ligand was synthesized via the reaction of 2-hydroxynpthaldehyd with N -phenyl-o-phenylenediamine. The obtained ligand was utilized in synthesizing Pt-L2 [PtCl(N^N^O)]. The ligand and Pt-L2 were characterized by IR, NMR and mass spectroscopies as well as elemental analysis. The DNA-binding of Pt-L2 was examined by fluorescence quenching using the EB-DNA adduct method. The apparent affinity for the compound toward ct-DNA was nearly twice the affinity of ethidium bromide. Changes in the relative viscosity induced by platinum complexes of ct-DNA indicated an intercalation mode of binding for Pt-L2 and covalent binding for the second platinum compound, Pt-L1, synthesized from 3-ethoxysalicyaldehyde and N -phenyl-o-phenylenediamine. BSA-binding by Pt-L2 indicated the spontaneous formation of an adduct with the protein with good binding affinity (7.7 × 104). The anticancer activities of Pt-L2 were evaluated against two cancer cell lines and compared to that of Pt-L1 and cisplatin. Pt-L2 has better IC 50 values, possibly because of its highly π-delocalized planar system. Moreover, selectivity index for Pt-L2 is high (SI = 168) which is one of the criteria for potential chemotherapeutic agents (higher than that observed for cisplatin (SI = 37)). [Display omitted] [ABSTRACT FROM AUTHOR]

• New cyclometalated bimetallic palladium(II) complexes are synthesized via C H bond activation. • Square planar geometries of the complexes are confirmed by X-ray crystallography. • Electronic structure and UV–vis spectra are interpreted by DFT and TDDFT calculations. • Interaction with CT DNA are studied by UV–vis and fluorescence method. • Palladium(II) complexes exhibit potential anti-cancer activity towards AGS cancer cell lines. Herein, we report the synthesis, characterization and in vitro anticancer activity of two μ -Cl and μ -O bridged dimeric cyclometalated palladium(II) complexes having general formula [Pd 2 (L1)Cl 2 ] (1) and [Pd 2 (L2)Cl 2 ] (2). The complexes are synthesized via palladium assisted aromatic C H bond activation of coordinating ligands (HL1/HL2) and thoroughly characterized by spectroscopic techniques. X-ray crystal structure analysis has confirmed the square planar geometry of the complexes. DFT and TDDFT results have interpreted the electronic structure and solution spectra of the complexes. Cytotoxicity of the complexes was studied by in vitro model with human gastric cancer cell lines (AGS). Cytotoxicity investigation reveals that the complexes have promising anti-cancer activity, with IC 50 values of 13.03 µM and 17.86 µM for 1 and 2 , respectively. UV–vis and fluorescence techniques are used to examine how the complexes interact with CT DNA. Fluorescence-based competitive binding analysis with ethidium bromide (EB) indicates that the complexes effectively displace EB from the EB-DNA complex. Herein, we report the synthesis of two μ -Cl and μ -O bridged dimeric palladium(II) complexes (1 / 2) via metal assisted aromatic C H bond activation. Geometries of the complexes are confirmed by single crystal X-ray diffraction method. Electronic structure and solution spectra of the complexes are interpreted by DFT and TDDFT calculations. In vitro cytotoxic activity of the complexes against human AGS gastric cancer cell lines by MTT colorimetric assay exhibit promising anti-cancer activities with IC 50 values of 13.03 µM and 17.86 µM for palladium(II) complexes 1 and 2 respectively. The interaction of the complexes with CT DNA are investigated by UV–vis and fluorescence methods. [Display omitted] [ABSTRACT FROM AUTHOR]

• Copper(II) complexes with non-steroidal anti–inflammatory drugs were characterized. • One structure was characterized by single-crystal X-ray crystallography. • The complexes show noteworthy antioxidant activity. • The complexes may bind reversibly to bovine serum albumin. • Intercalation is the interaction mode of complexes with calf-thymus DNA. Four novel copper(II) complexes with the non-steroidal anti-inflammatory drugs tolfenamic acid (Htolf), mefenamic acid (Hmef), naproxen (Hnap) and sodium diclofenac (Na dicl) were prepared in the presence of the N,N '–donor neocuproine (neoc) as co–ligand and were characterized by physicochemical and spectroscopic techniques. The complexes bear the formulas: [Cu(tolf) 2 (neoc)] (complex 1), [Cu(mef) 2 (neoc)] (complex 2), [Cu(nap) 2 (neoc)] (complex 3) and [Cu(dicl) 2 (neoc)] (complex 4), respectively. Single-crystal X-ray crystallography was employed to determine the crystal structure of complex [Cu(tolf) 2 (neoc)]. The in vitro scavenging activity of the complexes against 1,1–diphenyl–picrylhydrazyl and 2,2′–azinobis(3–ethylbenzothiazoline–6–sulfonic acid) free radicals and the ability to reduce H 2 O 2 were studied in the context of the antioxidant activity studies. The compounds interact with calf-thymus DNA via intercalation, as indicated by UV–vis spectroscopy and DNA–viscosity titration studies, and competitive studies with ethidium bromide. Additionally, the complexes were checked for their binding affinity to bovine serum albumin by fluorescence emission spectroscopy, and demonstrated significant and reversible binding to the albumin. [Display omitted] Four copper(II) complexes with non-steroidal anti-inflammatory drugs as ligands and neocuproine as co-ligand were prepared and characterized. The compounds present significant antioxidant activity, interact with calf-thymus DNA via intercalation and can bind tightly and reversibly to bovine serum albumin. [ABSTRACT FROM AUTHOR]

A novel series of nano-sized Co(II), Ni(II), Cu(II) and Zn(II) hybrids has been synthesized using the template method, i.e. by the in situ reaction of oxazin–Schiff's base [(E)-3-(2-(4-(diethylamino)-2-mercaptobenzylidene)hydrazineyl)-2H-benzo[b][1,4]oxazin-2-one] (HL) derived from 4-(diethylamino)-2-mercaptobenzaldehyde with 3-hydrazineyl-2H-benzo[b][1,4]oxazin-2-one in the presence of Co(II), Ni(II), Cu(II), Zn(II) chloride in ethanol. The structures and geometry of the optained compounds have been described by using the different analytical and spectroscopic tools such as elemental analysis, UV-VIS, IR, MS, 1H NMR, ESR, CV, TGA, XRD, SEM, AFM, magnetic and molar conductivity measurements. IR spectral studies confirmed the coordination of the ligand to the metal ions through the thiol sulfur, azomethine nitrogen and carbonyl oxygen. The Schiff's base ligand acts as monobasic tridentate OSN donor. The geometrical structures have been found to be octahedral and tetrahedral. The molar conductance measurements of the nano-sized hybrids in DMF and DMSO correspond to be nonelectrolytic nature for all nano-sized metal (II) hybrids. The elemental analyses confirm 1 M: 2 L stoichiometry of the type [ML 2 ] (M = Co(II), Ni(II), Cu(II) and Zn(II)). Electrochemical behaviour of nano-sized metal (II) hybrids were determined by cyclic voltammetry. Degradation pattern of the ligand HL and its nano-sized hybrids is shown by thermal studies. The activation of thermodynamic parameters are calculated using Coast-Redfern (CR) and Horowitz-Metzger (HM) methods. The data obtained from XRD, SEM, TEM and AFM images unequivocally asserted the nano-sized metal chelates. The percentage antioxidant activities are also more for complexes than the ligand. The investigated ligand and metal complexes were screened for their in-vitro antimicrobial activities against different types of fungal and bacterial strains. The resulting data assert on the inspected compounds as a highly promising bactericides and fungicides. The antitumor activities of all synthesized compounds were evaluated towards human liver Carcinoma (HepG2) cell line. DNA-binding, DNA cleavage and fluorescence properties of nano-sized hybrids with this ligand are reported. • Novel Schiff base (HL) ligand was prepared. • General formula of the synthesized hybrids is [ML 2 ]. • Molecular structures of the free ligand and its hybrids has been calculated. • Biological activities on different bacterial, fungal, cytotoxical, DNA binding/cleavage were examined. [ABSTRACT FROM AUTHOR]

Abstract New series of benzothiazole-1,2,3-triazoles; appended with benzothiazole, isatin and/or benzimidazole moiety; were designed and synthesized through the click chemistry approach. The syntheses proceeded [Cu(I) catalyzed] 1,3-dipolar cycloaddition between the appropriate alkyne based benzothiazole, isatin and/or benzimidazole with un/substituted benzothiazole azide. The synthesized compounds were characterized by FT-IR, Mass and NMR methods. The DNA binding constants (Kb) were in the range of 1.732 × 105 to 3.191 × 105 M−1; indicating good binding tendency of the compounds with DNA. Nearly all the compounds intercalated with DNA through the minor grooves via covalent, intercalative and electrostatic bondings. Total nine compounds indicated more than 50% anticancer activities with colorectal (SW182) and lung (H199) cancer cell lines. The docking studies indicated quite good binding affinities (−3.7 to −5.4 kcal/mol) of the reported compounds with DNA. The experimental results of DNA bindings were in good agreement with those of docking studies. The reported compounds may be potential future candidates for anticancer treatment. Highlights • Novel benzothiazole moiety were designed and synthesized via click reaction. • Synthesized compounds showed excellent anticancer activity (91.95%). • Molecular docking and DNA studies indicated anticancer activities via DNA binding. • Synthesized compounds are future anticancer drugs. [ABSTRACT FROM AUTHOR]

Abstract Two N -substituted 2-methyl-4-/5-nitroimidazole derivatives (3 & 4) have been synthesized by K 2 CO 3 catalyzed reaction between 2-methyl-5-nitro-1 H -imidazole (1) or metronidazole (2) and acrylonitrile. The derivates were obtained in good yields and characterized by IR spectroscopy, 1H-NMR spectroscopy, and ESI-MS mass spectrometry. Single-crystal X-ray structure analysis supported the formation of the derivatives, which were further complemented by DFT studies. The in-vitro anticancer activity against human colon cancer cell line (SW-480) has also been performed. To underpin the affinity of the reported derivatives towards nucleic acids, both in-vitro (ct -DNA binding studies) and in-silico (docking studies) techniques were employed. Despite their small sizeand the presence of pharmacologically active core, both 3 (IC 50 > 160 μg/mL, K b = 0.3 × 105 M−1, ΔG = −5.4 kcal/mol) and 4 (IC 50 > 160 μg/mL, K b = 3.0 × 105 M−1, ΔG = −5.6 kcal/mol) exhibited moderate anticancer activity and DNA affinity. Graphical abstract Image 1 Highlights • N -substituted 2-methyl-4-/5-nitroimidazole derivatives were synthesized. • Derivatives were characterized by different spectroscopic techniques. • The structure of hybrids was confirmed by X-ray crystallography. • DFT studies were conducted to further support the structure. • In vitro DNA binding, cell viability and docking studies were carried out. [ABSTRACT FROM AUTHOR]

Trans -[Cu(O∩O) 2 ] complex, O∩O = 4,4,4-trifluoro-1-(thiophen-2-yl)butane-1,3-dione was reported with high potential toward CT-DNA binder. The solved XRD-structure of complex indicated a perfect regular square-planer geometry around the Cu(II) center. The trans/cis -DFT-isomerization calculation supported the XRD seen in reflecting the trans -isomer as the kinetic-favor isomer. The desired complex structure was also characterized by conductivity measurement, CHN-elemental analyses, MS, EDX, SEM, UV–Vis., FT-IR, HAS and TG/DTG. The Solvatochromism behavior of the complex was evaluated using four different polar solvents. MPE and Hirshfeld surface analysis (HSA) come to an agreement that fluoride and thiophene protons atoms are with suitable electro-potential environment to form non-classical H-bonds of type C Th H⋯F. The DNA-binding properties were investigated by viscosity tests and spectrometric titrations, the results revealed the complex as strong calf-thymus DNA binder. High intrinsic-binding constants value ∼1.8 × 10 5 was collected. [ABSTRACT FROM AUTHOR]

• Three new Ln 3 compounds have been synthesized and structurally characterized. • 1 and 2 display typical NIR luminescence of Nd(III) and Sm(III) at room temperature. • Biological activities research reveals that 1–3 have greater antibacterial activity than the ligand H 2 L and Ln(dbm) 3 ·2H 2 O. • The interaction between compounds 1–3 and calf thymus DNA was studied. Three new trinuclear lantharide-based compounds: [Ln 3 (dbm) 5 (L) 2 (CH 3 OH)]·CH 2 Cl 2 (LnIII = Nd(1), Sm(2), and Tb(3), dbm− = diphthaloylmethae) have been synthesized via the solvothermal method by using a polydentate Schiff base ligand (H 2 L = (E)-6-(hydroxymethyl)-N'-((6-methoxypyridin-2-yl)methylene)picolinohydrazide) reacting with Ln(dbm) 3 ·2H 2 O. X-ray diffraction study reveals that all compounds 1 – 3 belong to monoclinic crystal system with space group C 2/c, and compounds 1 – 3 are isostructural and possess a broken-line Ln 3 core. The solid-state luminescence properties measurements indicate that compound 3 displays the characteristic lanthanide luminescence at room temperature. Moreover, photoluminescence properties study show that 1 and 2 display typical NIR luminescence of Nd(III) and Sm(III) ions at room temperature. Furthermore, biological activities research reveals that compounds 1–3 have greater antibacterial activity than the ligand H 2 L and Ln(dbm) 3 ·2H 2 O (LnIII = Nd (1), Sm (2), and Tb (3)). The interaction between compounds 1–3 and calf thymus DNA was studied and the results revealed that the compounds were mainly intercalated with calf thymus DNA. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper reports the synthesis, X-ray crystal structure, DNA-binding, antibacterial and antifungal studies of a rare dihydroxo-bridged dinuclear copper(II) complex including 1,10-phenanthroline (Phen) ligands and phenylacetate (L) anions, [Cu 2 (Phen) 2 (OH) 2 (H 2 O) 2 ].2L.6H 2 O. Structural data revealed distorted square-pyramidal geometry for each copper(II) atom with the basal plane formed by the two nitrogen atoms of the phenantroline ligand and the oxygen atoms of two bridging hydroxyl groups. The apical positions are filled by the oxygen atom from a water molecule. This forms a centrosymmetric cationic dimer where the uncoordinated phenylacetate ligands serve to balance the electrical charge. The dimers interact by means of hydrogen bonds aided by the coordinated as well as uncoordinated water molecules and phenyl-acetate moieties in the crystal lattice. The binding ability of the complex with salmon sperm DNA was determined using cyclic voltammetry and absorption spectroscopy yielding binding constants 2.426 × 10 4 M −1 and 1.399 × 10 4 M −1 , respectively. The complex was screened against two Gram-positive ( Micrococcus luteus and Bacillus subtilis ) and one Gram-negative ( Escherichia coli ) bacterial strains exhibiting significant activity against all the three strains. The complex exhibited significant, moderate and no activity against fungal strains Mucor piriformis , Helminthosporium solani and Aspergillus Niger , respectively. These preliminary tests indicate the competence of the complex towards the development of a potent biological drug. [ABSTRACT FROM AUTHOR]

The binding of the lanthanum(III) complex containing 1,10-phenanthroline (phen), [La(phen) 3 Cl 3 ·OH 2 ], to DNA is investigated by absorption and emission methods. This complex shows absorption decreasing in a charge transfer band, and fluorescence decrement when it binds to DNA. Electronic absorption spectroscopy (UV–Vis), fluorescence spectra, iodide quenching experiments, salt effect and viscosity measurements, ethidium bromide (EB) competition test, circular dichroism (CD) spectra as well as variable temperature experiments indicate that the La(III) complex binds to fish salmon (FS) DNA, presumably via groove binding mode. The binding constants (K b ) of the La(III) complex with DNA is (2.55 ± 0.02) × 10 6 M −1 . Furthermore, the binding site size, n, the Stern–Volmer constant K SV and thermodynamic parameters; enthalpy change (ΔH 0 ) and entropy change (ΔS 0 ) and Gibb's free energy (ΔG 0 ), are calculated according to relevant fluorescent data and the Van't Hoff equation. The La(III) complex has been screened for its antibacterial activities by the disc diffusion method. Also, in order to supplement the experimental findings, DFT computation and NBO analysis are carried out. [ABSTRACT FROM AUTHOR]

• Three new Cu(II) complexes of diimine ligand were prepared. • The crystal structures of Cu(II) complexes have been determined. • DNA/BSA binding behaviors of Cu(II) complexes are performed using electronic absorption titrations and fluorescence spectral studies. • The cytotoxicity of complexes in vitro was evaluated. • The apoptosis-inducing activity was assessed by Annexin-V/PI double staining assay. Three copper(II) complexes, [Cu(phen) 2 Cl](3,5-DNB) (3,5-HDNB) (1), [Cu(phen)(4-NB) 2 (H 2 O)] (2), and [Cu(2,2′-bipy)(4-NB) 2 (H 2 O)] (3), [phen = 1,10-phenanthroline, 2,2′-bipy = 2,2′-bipyridine, 3,5-DNB = 3,5-dinitrobenzoate anion, 3,5-HDNB = 3,5-dinitrobenzoic acid, 4-NB = 4-nitrobenzoate], have been synthesized and characterized. The interactions between three complexes and HS-DNA/BSA were determined by UV and fluorescence spectra. The results suggest that these copper(II) complexes interact with HS-DNA in an intercalative way and quench the intrinsic fluorescence of BSA via a static mechanism. The fluorescence data also indicated the complexes exhibited good binding propensity to BSA and the binding site available on BSA for the complexes was only one. The antiproliferative activity of the three complexes against several tumor cell lines (MCF-7, HepG-2, A549, and HeLa) was tested by MTT method. Three complexes displayed cytotoxicity against four tumor cells, but complex 3 is less cytotoxic than complexes 1-2. Moreover, the apoptosis was measured by the Annexin-V/PI double staining methods and the results demonstrated that complex 1 and 2 could induce apoptosis in MCF-7 and HeLa cells, respectively. [ABSTRACT FROM AUTHOR]

• Four new Co(II) complexes with fenamato, tolfenamato, niflumato ligands and neocuproine were designed and synthesized to investigate impact of ligand structure on biological properties. • Crystal structures of prepared complexes were determined by single-crystal X-ray diffraction. • Fenamato and tolfenamato complexes with analogous structure were characterized by spectral measurements. • DNA and albumin binding studies as well as radical scavenging experiments were performed on fenamato and tolfenamato complexes to explore their biological activity. • Obtained results indicate considerable effect of additional substituents present in tolfenamato ligand on final properties of the complex. Four novel cobalt(II) complexes with the non-steroidal anti-inflammatory drugs - fenamic acid derivatives have been synthesized and characterized. The complexes [Co(neo)(fen) 2 ] (1) and [Co(neo)(tol) 2 ] (2) were prepared by the reaction of fenamic (H fen = 2-(phenylamino)benzoic acid) and tolfenamic acid (H tol = 2-[(3-chloro-2-methylphenyl)amino]benzoic acid), respectively with cobalt(II) chloride and neocuproine (neo = 2,9-dimethylphenantroline). However, the same procedure applied to niflumic acid (H nif = 2-{[3-(trifluoromethyl)phenyl]amino}nicotinic acid) mixture has led to formation of [Co(neo)(nif) 2 (MeOH)]·MeOH (3A) and [CoCl(neo)(nif)(MeOH)] (3B). The crystal structure of all prepared compounds has been determined by single-crystal X-ray crystallography. Complexes 1 and 2 were further subjected to full spectral characterization (IR, UV-VIS, fluorescence) as well as biological activity studies. The radical scavenging activity against free model radicals ABTS (diammonium 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonate) and DPPH (2,2-Diphenyl-1-picrylhydrazyl) revealed the selectivity of complexes against ABTS with higher scavenging activity observed for 2 , while both compounds were ineffective towards DPPH. Furthermore, the interaction of molecules with Fish-sperm DNA revealed a moderately strong interaction based on combined intercalative and minor-groove binding mode. The interaction with human and bovine serum albumins determined by fluorescence quenching experiments revealed the binding constants within the optimal range proposed for effective drug binding. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, a new porphyrin-Schiff base ligand (L) and its metal complexes (Cu(II), Fe(III), Mn(III), Pt(II) and Zn(II)) were synthesized. The starting material 4-ethyl-2,6-bis(hydroxymethyl)phenol (A) was synthesized from 4-ethylphenol and formaldehyde in the alkaline media. The compound (A) was then oxidized to the 4-ethyl-2,6-diformylphenol (B). The starting compounds (A) and (B) were obtained as single crystals. Structures of the compounds (A) and (B) were determined by the X-ray crytallography technique. The porphyrin ligand (L) and its metal complexes were characterized by the analytical and spectroscopic methods. Electronic, electrochemical and thermal properties of the synthesised compounds were investigated. Superoxide dismutase activities (SOD) of the porphyrin Schiff base complexes were investigated and results were discussed. Additionally, the DNA (fish sperm FSdsDNA) binding studies of the complexes were performed using UV–vis spectroscopy. Competitive studies with ethidium bromide (EB) show that the compounds interact efficiently with DNA through an intercalating way. [ABSTRACT FROM AUTHOR]

• DNA binding of three Pd(II) complexes were studied using different methods. • The metal complexes showed antitumor activity against MCF-7cancer cell line. • DFT calculations were performed for these Pd(II) complexes. • Docking simulation revealed all complexes have groove binding mode with DNA. Three metal complexes wherein picolinic acid (dipic) diversely coordinated to palladium with formula trans-[Pd(Hdipic) 2 ].2H 2 O (I), K[Pd(dipic)Cl].H 2 O (II) and trans-Na 2 [Pd(dipic) 2 ].2H 2 O (III) had been selected from literature and accordingly made them in our laboratory. Complex ions of these three compounds bear 0.00 (I), -1.00 (II), and -2.00 (III) charges. In this study, DFT calculations i.e., molecular geometry analysis, molecular electrostatic potential map and frontier molecular orbital analysis were performed for the Pd(II) complexes I, II and III. Preliminary cytotoxic activity of them along with carboplatin as standard, against cancer cell line MCF-7, showed the promising effect. Thus in-detail interaction of I, II , and III with calf thymus DNA was investigated through spectrophotometric, fluorometric, partition coefficient, viscometric measurement, gel electrophoresis, and docking assay for more analysis. All the data obtained from these above studies indicate that the complex with zero charge (I) shows better cytotoxic and DNA interaction affinity than the II and III having -1.00 and -2.00 charges which might be due to their repulsion by negative charges present on phosphate diester of the DNA backbone. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights: [•] A new mononuclear ternary copper(II) complex was synthesized and characterized by X-ray analysis. [•] The in vitro anticancer activities suggest that the copper(II) complex is active against the selected tumor cell lines. [•] The interaction of the complex with DNA was investigated both theoretically and experimentally. [•] The influence of binding fashion of the picrate anions on the structure, cytotoxicity and DNA-binding property was studied. [ABSTRACT FROM AUTHOR]

Abstract: A new mononuclear copper(II) complex with formula of [Cu2H(DABTA)2](pic)⋅6H2O, where H2DABTA and pic− stand for N,N′-(4,4′-bithiazole-2,2′-diyl)diacetimidamide and picrate ion, respectively, has been synthesized and characterized by elemental analysis, molar conductivity measurement, IR and electronic spectra studies, and single-crystal X-ray diffraction. The crystal structure reveals that the copper(II) ion has a {CuN4} square-planar coordination environment. The solvent water molecules form a column parallel to c axis by hydrogen bonds. Then the mononuclear copper complexes link to the water columns to make a three-dimensional hydrogen bonding grid with the cavities filled by pic− anions. Besides, there are offset π–π stacking interactions between thiazole rings in the supramolecular system. The interactions between the copper(II) complex and herring sperm DNA (HS-DNA) have been investigated by using electronic absorption titration, fluorescence titration and viscometry. The molecular docking of the complex with the self-complementary DNA duplex of sequence d(ACCGACGTCGGT)2 demonstrates that the complex is stabilized by additional electrostatic and hydrogen bonding interaction with the DNA. The copper(II) complex exhibits potent anticancer activities against human hepatocellular carcinoma cell SMMC-7721 and human lung adenocarcinoma cell A549. [Copyright &y& Elsevier]

Abstract: A new charge transfer (CT) complex [(DAPH)+(DNB)−] consisting of 2,6-diaminopyridine (DAP) as donor and 3,5-dinitrobenzoic acid (DNB-H) as acceptor, was synthesized and characterized by FTIR, 1H and 13C NMR, ESI mass spectroscopic and X-ray crystallographic techniques. The hydrogen bonding (N+–H⋯O−) plays an important role to consolidate the cation and anion together. CT complex shows a considerable interaction with Calf thymus DNA. The CT complex was also tested for its antibacterial activity against two Gram-positive bacteria Staphylococcus aureus and Bacillus subtilis and two Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa strains by using Tetracycline as standard, and antifungal property against Aspergillus niger, Candida albicans, and Penicillium sp. by using Nystatin as standard. The results were compared with standard drugs and significant conclusions were obtained. A polymeric net work through H-bonding interactions between neighboring moieties was observed. This has been attributed to the formation of 1:1 type CT complex. [Copyright &y& Elsevier]

Abstract: Three new ruthenium(II) complexes, [Ru(MeIm)4phen]2+ (1), [Ru(MeIm)4ip]2+ (2) and [Ru(MeIm)4pip]2+ (3), have been synthesized and characterized. The binding properties of the three complexes towards calf-thymus DNA were investigated by different spectrophotometric methods and viscosity measurements. In addition, the cytotoxicity of these complexes has been evaluated by MTT method and Giemsa staining experiment. The main results reveal that the plane area and hydrophobicity of intercalative ligands have a significant effect on the DNA-binding behaviors and the IC50 value of complex 2 against MCF-7 cells is close to that of cis-Pt(NH3)2Cl2. [Copyright &y& Elsevier]

Abstract: A new series of nickel(II) complexes with the tetraaza macrocyclic ligand have been synthesized as possible functional models for nickel–superoxide dismutase enzyme. The reaction of 5-amino-3-methyl-1-phenylpyrazole-4-carbaldehyde (AMPC) with itself in the presence of nickel(II) ion yields, the new macrocyclic cationic complex, [NiL(NO3)2], containing a ligand composed of the self-condensed AMPC (4mol) bound to a single nickel(II) ion. A series of metathetical reactions have led to the isolation of a number of newly complexes of the types [NiL]X2; X=ClO4 and BF4, [NiLX2], X=Cl and Br (). Structures and characterizations of these complexes were achieved by several physicochemical methods namely, elemental analysis, magnetic moment, conductivity, and spectral (IR and UV–Vis) measurements. The electrochemical properties and thermal behaviors of these chelates were investigated by using cyclic voltammetry and thermogravimetric analysis (TGA and DTG) techniques. A distorted octahedral stereochemistry has been proposed for the six-coordinate nitrato, and halogeno complexes. For the four-coordinate, perchlorate and fluoroborate, complex species a square-planar geometry is proposed. The measured superoxide dismutase mimetic activities of the complexes indicated that they are potent NiSOD mimics and their activities are compared with those obtained previously for nickel(II) complexes. The probable mechanistic implications of the catalytic dismutation of by the synthesized nickel(II) complexes are discussed. The DNA-binding properties of representative complexes [NiLCl2] and [NiL](PF4)2 have been investigated by the electronic absorption and fluorescence measurements. The results obtained suggest that these complexes bind to DNA via an intercalation binding mode and the binding affinity for DNA follows the order: [NiLCl2] □ [NiL](PF4)2. [Copyright &y& Elsevier]

Abstract: Two new ruthenium(II) complexes [Ru(dmp)2(DNPIP)]2+ 1 and [Ru(dmp)2(DAPIP)]2+ 2 were synthesized and characterized. The DNA-binding behaviors of these complexes were investigated by absorption spectra, viscosity measurements and photocleavage. The DNA-binding constants for complexes 1 and 2 have been determined to be 6.24 (±0.11)×104 and 1.64 (±0.49)×104 M−1. The results suggest that complexes 1 and 2 intercalate between the DNA base pairs. Binding stoichiometries were studied through a luminescence-based Job plot. The major inflection points for complexes 1 and 2 at χ =0.31 and χ =0.51 were observed. The data were consistent with 2:1 and 1:1bp [complex]/[DNA] binding mode. Complex 1 shows higher activity than complex 2 against the selected tumor cell lines. In addition, the cellular uptake and antioxidant activity on hydroxyl radical were also explored. [Copyright &y& Elsevier]

Abstract: A new Ru(II) complex [Ru(dmb)2(pdta)](ClO4)2 (1) (dmb=4,4′-dimethyl-2,2′-bipyridine, pdta=3-(pyridine-2-yl)-as-triazino [5,6-f]-acenaphthylene) was synthesized and characterized by elemental analysis (EA), ES–MS, 1H NMR, UV–Vis and CV. The DNA-binding properties of complex 1 were investigated by absorption titration, thermal denaturation, viscosity measurement and photoactivated cleavage. The DNA-binding constant was determined to be 2.37±0.14×105 M−1 (s =1.90±0.04) by electronic absorption titration, indicating that complex 1 interacts with DNA through intercalative mode. The redox peak potentials of this complex in CV were rationally assigned with the frontier molecular orbital stereographs resulting from the density functional theory (DFT) calculation. The photoactivated cleavage and cleavage mechanism of plasmid pBR322 DNA in the presence of complex 1 and various inhibitors were studied. The experiment for detecting the formation of singlet oxygen photo-sensitized by complex 1 was carried out, and the antioxidant activity of the Ru-complex and the ligand pdta against hydroxyl radical was also investigated. [Copyright &y& Elsevier]

Abstract: Proton or charge transfer (CT) complex of donor, 1,10-phenanthroline (Phen) with π-acceptor, p-Nitrophenol (PNP) has been studied spectrophotometrically in methanol at room temperature. The binding of the CT complex with calf thymus (ct) DNA has been investigated by fluorescence spectrum, to establish the ability of the CT complex of its interaction with DNA. Stern–Volmer quenching constant (Ksv) has also been calculated. The formation constant (K CT), molar extinction coefficient (ε CT), free energy (ΔG o) and stoichiometric ratio of the CT complex have been determined by Benesi–Hildebrand equation. The stoichiometry was found to be 1:1. The CT complex was screened for its pharmacology as antibacterial and antifungal activity against various bacterial and fungal strains, showing excellent antibacterial and antifungal activity. The newly synthesized CT complex has been characterized by FTIR spectra, elemental analysis, 1H NMR, electronic absorption spectra. TGA–DTA studies were also carried out to check the stability of CT complex. [Copyright &y& Elsevier]

Two new ruthenium(II) polypyridyl complexes [Ru(dmb)2(maip)](ClO4)2 1 (maip=2-(3-aminophenyl)imizado[4,5-f][1,10]phenanthroline and [Ru(dmb)2(maip)](ClO4)2 2 (paip=2-(4-aminophenyl)imidazo[4,5-f][1,10]phenanthroline, dmb=4,4′-dimethyl-2,2′-bipyridine) have been synthesized and characterized. The DNA-binding behaviors of complexes 1 and 2 were studied by viscosity measurements, thermal denaturation, photocleavage, absorption titration and luminescence spectra. The results show that the two complexes intercalate between the base pairs of DNA. The DNA-binding constants Kb for complexes 1 and 2 were determined to be 1.12±0.11×105M−1 (s=2.17) and 3.46±0.59×105M−1 (s=2.11) M−1. The studies on the mechanism of photocleavage demonstrate that superoxide anion radical (O2−) and singlet oxygen (1O2) may play an important role. The cytotoxicity of these complexes has been evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The IC50 values are 19.21, 33.15, 38.57 and 21.15 for complex 1 and 41.77, 123.58, 255.44 and 49.11 for complex 2 against BEL-7402, C-6, HepG-2 and MCF-7 cell lines, respectively. The apoptosis assay was carried out with acridine orange/ethidium bromide (AO/EB) staining methods and the results indicate that complexes can induce the apoptosis of BEL-7402 cells. The experiments on antioxidant activity show these complexes exhibit good antioxidant activity against hydroxyl radical (OH). [Copyright &y& Elsevier]

Abstract: A novel ligand idpq with embedded C two complexes, [Ru(bpy)2(idpq)]2+ 1 and [Ru(phen)2(idpq)]2+ 2 (bpy=2,2′-bipyridine; phen=1,10-phenanthroline; idpq=indeno[1,2-b]dipyrido [3,2-f:2′,3′-h]-quinoxaline-6-one), have been synthesized and characterized by elemental analysis, ES-MS, 1H NMR, UV–vis and CV. The DNA-binding behaviors of both complexes were studied by spectroscopic methods and viscosity measurements. The results indicate that the two complexes can all bind to CT-DNA in an intercalative mode, and they have rather high DNA-binding constants, which are (1.7±0.4)×106 M−1 and (4.0±0.6)×106 M−1, respectively. The results also show that these two Ru(II) complexes can promote photocleavage of pBR322 DNA. Their DNA-binding and electronic absorption-spectral properties were further studied by the DFT/TDDFT methods. The DNA-binding behaviors and difference of these complexes were reasonably explained, and the simulated absorption spectra were in good agreement with the experimental ones. [Copyright &y& Elsevier]

• Novel Zn(II) niflumato complex with neocuproine was designed and synthesized. • Prepared complex was characterized by spectral measurements and X-ray diffraction. • Cytotoxic effect of the complex on endometriotic cell lines hTERT and 12Z was investigated. • Studied complex shows higher antiproliferative activity against 12Z cell line. • Further studies suggest that DNA binding might be involved in its cytotoxic mechanism. Novel zinc niflumato complex with a composition of [Zn(neo)(nif) 2 ] (neo = neocuproine; nif = niflumato) was prepared in crystalline form and characterized by elemental analysis and spectroscopic methods (IR, UV/VIS and fluorescence). According to the results of the single-crystal X-ray structural analysis the central Zn(II) atoms within the complex molecules are tetracoordinated by two oxygen atoms of nif ligands and two nitrogen atoms of chelate bonded neo. The cytotoxic measurements on two endometrial cell lines hTERT and 12Z indicate selectivity of the complex towards the endometriotic 12Z cell line. In addition, spectral binding studies performed on isolated DNA samples revealed higher affinity of the complex to the 12Z DNA, thus suggesting possible specific DNA sequence recognition. [ABSTRACT FROM AUTHOR]

• Mn(II) and Fe(II) complexes of N,N-heterocyclic amines were prepared. • Mn(II) complexes possessed chelating and bridging ligands. • Fe(II) complex crystallized two independent Fe centers. • DNA binding behaviors are performed using absorption and emission spectra. • The anticancer and inducing apoptosis activities of all compounds were tested. Three new complexes, {[Mn(2,2′-bipy)(4,4′-bipy) 0.5 (4-sb)(H 2 O)](H 2 O) 2 } n (1), [Mn(phen) 2 (4-sb)(H 2 O)](4,4′-bipy) 0.5 (H 2 O) 3 (2), and [Fe 2 (phen) 6 ](4-Hsb)(H 2 O) 5 (3) [4-sb = 4-sulfobenzoate dianion, 2,2′-bipy = 2,2′-bipyridine, 4,4′-bipy = 4,4′-bipyridine, phen = 1,10-phenanthroline], have been synthesized and structurally characterized. The interaction of complex with HS-DNA was investigated by carrying out UV−vis absorption spectrum and fluorescence ethidium bromide displacement experiment. The DNA-binding constants K b of complexes 1, 2 , and 3 were calculated to be 7.39 × 105 M−1, 3.94 × 105 M−1, and 9.34 × 105 M−1, respectively. The results indicated that these complexes interact with HS-DNA through intercalative mode. Competitive studies with ethidium bromide (EB) further showed that the complexes bind to DNA probably via intercalation. The complexes were tested for antiproliferative activities on a panel of cell lines (MCF-7, HepG-2, A549, BGC823, and HTR-8) by MTT method, three complexes can inhibit the tumor cell proliferation, but complex 1 is less cytotoxic than other two complexes. The apoptosis assay was assessed with the Annexin-V/PI double staining methods and the results revealed that complexes induced the HepG-2 cells apoptosis. [ABSTRACT FROM AUTHOR]

This work proceeding with novel neutral water soluble complex of kind [CuCl(O–O)(N–N)], [where O–O = ß-diketone, 4,4,4-trifluoro-1-phenylbutane-1,3-dione (dione) and N–N = 1,10-phenanthroline (phen)] preparation and identification. The structure of complex together with the DFT-optimization indicated a slightly distorted square-pyramidal geometry surround the copper (II) atom with Cu–Cl bond elongated. Theoretical Hirshfeld surface (HSA) and Molecular Electrostatic Potential (MEP) analysis tougher with the Exp. XDR-crystal packing supported the formation of non-classical C ph -F ....H H-bonds. The prepared complex was molecularly identified based on: elemental analyses, conductivity measurement, UV–Vis., MS, HSA, FT-IR, and TG/DTG. The solvatochromism behaviors of the complex in several polar solvents like: DMSO, MeOH, H 2 O, and DMF were evaluated; the solvents effect on the complex structure fluxionality was explained via Guttmann's relation. Absorption, viscosity and melting temperature investigations reflected the desired complex as a honorable CT-DNA coordinator. • [Cu(phen)(dione)Cl] complex was prepared and spectrally characterized. • The structure of the complex was solved by XRD and computed by HAS/DFT. • The thermal, spectral, solvatochromism and MEP were reported. • The desired complex reflected a very good CT-DNA binder. [ABSTRACT FROM AUTHOR]

A simple highly adjustable and effective synthesis of aryl imidazole ligand HL namely (2-(1-butyl-4,5-diphenyl-1H-imidazole-2-yl) (4-bromophenol) was discussed where it was prepared by cyclo condensation of 5-bromo-2-hydroxybenzaldehyde, benzil and butan-1-amine. Three new Cr(III), Fe(III) and Cu(II) coordination compounds of aryl imidazole ligand were synthesized. The multi-substituted aryl imidazole ligand (HL) and its coordination compounds were characterized via a wide range of spectroscopic and analytical tools such as 1H NMR and 13C NMR, infrared (IR) and UV–Vis spectrophotometry, conductivity and magnetic measurements. The crystal and molecular structure of aryl imidazole ligand HL were discussed by using maXus. The structure of the titled aryl imidazole ligand HL and its metal coordination compounds were discussed theoretically by using Gaussian 09 program at the B3LYP/LANL2DZ level of theory. The obtained data showed that the new compounds have 1:1 M ratio (metal: ligand) and non-electrolytes in nature. The newly prepared [Cr(L)Cl 2 (H 2 O) 2 , [Fe(L)(NO 3) 2 (H 2 O) 2 and [Cu(L)Cl(H 2 O) 3 coordination compounds have a distorted-octahedral geometry. Density Functional Theory (DFT) calculations have been carried out to investigate the equilibrium geometry of the ligands and its coordination compound using Gaussian 09 program at the B3LYP/LANL2DZ level. Moreover, the new compounds were tested against the selected species of microorganism namely Staphylococcus aureus (+ ve), Pseudomonas aeruginosa (-ve), Escherichia coli (-ve) and also against Candida albicans , Aspergillus flavus and Trichophyton Rubrumin. The result revealed that new compounds showed high efficacy towards the growth inhibition of the selected pathogenic microorganism. Moreover, the interaction of the new coordination compounds with CT-DNA was studied by absorption spectra, gel electrophoresis and viscosity techniques. The result showed that the interaction of the new coordination compounds with CT-DNA is an intercalative binding mode. Furthermore, the growth inhibitory effects of the new compounds were tested against Hep-G2, MCF-7 and HCT-116 cell lines. Moreover, all complexes exhibited stronger cytotoxicity effect on the outgrowth of different types of carcinoma cells, than their corresponding imidazole ligand and follow the order: CuL > CrL > FeL > HL. Image 1 • Three new CrL, FeL and CuL compounds were synthesized. • The suggested structures were confirmed by physicochemical and spectral techniques. • The new compounds were tested against selected species of microorganism. • The interaction mode of the new compounds with CT-DNA is an intercalation. • Anticacer potency was tested against Hep-G2 cell line, MCF-7 cell line and HCT-116 cell lines. [ABSTRACT FROM AUTHOR]