Search

The title compound, [Cu(C11H15N2O)(C12H8N2)]ClO4 or [Cu(L)(phen)](ClO4) {where L refers to the deprotonated form of 2-[(2-dimethylaminoethylimino)methyl]phenol} and phen is 1,10-phenanthroline) is a mononuclear mixed ligand copper(II) complex. The CuII atom is coordinated by two N and one O atoms of the tridentate Schiff base ligand (HL) and two N atoms of the 1,10-phenanthroline ligand, resulting in a five-coordinate complex. The asymmetric unit of the title complex contains two crystallographically independent complex cations (a and b) with a slightly different geometry around the CuII ion. The value of the trigonality index τ, indicates that in both cations a and b, the CuII atoms display a square-pyramidal distorted trigonal–bipyramidal (SPDTBP) geometry, although the distortion is greater for cation a.

Recently, mixed-ligand copper(II) complexes have received much attention in searching for alternative metallodrug for cisplatin. A series of mixed ligand Cu(II) complexes of the type [Cu(L)(diimine)](ClO4) 1-6, where HL is...

This work aimed to investigate the interaction of bovine serum albumin with newly synthesized potent new pyrene derivatives (PS1 and PS2), which might prove useful to have a better antibacterial character as found for similar compounds in the previous report [Low et al.

Organometallic Ru-arene complexes are promising as anticancer agents, but the lack of tumor uptake and poor solubility in the physiological medium impede their development. In order to deal with these challenges, we developed gold nanoparticles coated with Ru(arene)-functionalized PNVP-Py, where PNVP-Py is pyridine end-functionalized poly(N-vinylpyrrolidone). It is demonstrated that these particles exhibit higher anti-proliferative activity than the individual organometallic ruthenium(ii) complex of the type [Ru(η6-p-cymene)(NN)Cl]PF6, where NN is bis(4-methoxyphenylimino)acenaphthene, against colorectal adenocarcinoma cell lines. More specifically, a RuII(η6-p-cymene) complex containing a NN bidentate ligand has been prepared and characterized by spectral studies and X-ray crystallography. To tether the isolated complex onto the surface of the AuNPs, PNVP-Py, which contains a pyridine group at one end to coordinate to the Ru-complex and a suitable functional group at the other end to bind on the surface of the AuNPs, has been prepared and utilized to obtain the macromolecular complex [Ru(η6-p-cymene)(NN)(PNVP-Py)]Cl2. Next, stable Ru(p-cym)(NN)(PNVP-Py)@AuNPs were obtained via a ligand exchange reaction of citrate-stabilized AuNPs with a macromolecular complex by a direct 'grafting to' approach and characterized well. Despite the lower DNA cleavage activity, the nanoconjugate exhibits better cytotoxicity than the individual complex against HT-29 colorectal adenocarcinoma cells on account of its enhanced permeability across the cell membrane. The AO/EB staining assay revealed that the nanoconjugate is able to induce an apoptotic mode of cell death, which was further quantitatively evaluated by Annexin V-FITC/PI double assay. An immunofluorescence assay indicated the higher potency of the nanoconjugate to inhibit cyclin D1 gene expression that is required for cancer cell growth. To the best of our knowledge, this is the first report of the modification of an organometallic Ru(arene) complex into a Ru(arene)metallopolymer-gold nanoconjugate for the development of ruthenium-based nanomedicine for cancer treatment.

The development of molecular catalysts for the activation and conversion of atmospheric carbon dioxide (CO2) into a value-added product is a great challenge. A series of nickel(II) complexes, [Ni(L)(CH3CN)3](BPh4)2, 1–4 of diazepane based ligands, 4-methyl-1-[(pyridin-2-yl-methyl)]-1,4-diazepane (L1), 4-methyl-1-[2-(pyridine-2-yl)ethyl]-1,4-diazepane (L2), 4-methyl-1-[(quinoline-2-yl)-methyl]-1,4-diazepane (L3) and 1-[(4-methoxy-3,5-dimethyl-pyridin-2-yl)methyl]-4-methyl-1,4-diazepane (L4), have been synthesized and characterized as catalysts for the activation of atmospheric CO2. The single-crystal X-ray structure of 1 shows a distorted octahedral geometry with a cis-β configuration around the NiN6 coordination sphere. All the complexes are used as catalysts for the conversion of atmospheric CO2 and epoxides into cyclic carbonates at 1 atmosphere (atm) pressure and in the presence of Et3N. Catalyst 4 was found to be the most efficient catalyst and showed a 31% formation of cyclic carbonates with a TON of 620 under 1 atm air as the CO2 source. This yield was enhanced to 94% with a TON of 1880 under 1 atm pure CO2 gas and it is the highest catalytic efficiency known for nickel(II)-based catalysts. Catalyst 4 enabled the transformation of a wide range of epoxides (eight examples) into corresponding cyclic carbonates with excellent selectivity (>99%) and yields of 59–94% and 11–31% under pure CO2 and atmospheric CO2, respectively. The catalytic efficiency is strongly influenced by the electronic nature of the complexes. The CO2 fixation reactions without an epoxide substrate led to the formation of the carbonate bridged dinuclear nickel(II) complexes [(LNiII)2CO3](BPh4)21a–4a, which are speculated as catalytically active intermediates. The formation of these species was accompanied by the formation of new absorption bands around 592–681 nm and was further confirmed by the ESI-MS and IR spectral studies. The molecular structures of these carbonate-bridged key intermediates were determined by X-ray analysis. The structures contain two Ni2+-centers bridged via a carbonate ion that originated from CO2. Distorted square pyramidal geometries are adopted around each Ni(II) center. All these results support that CO2 fixation reactions occur via CO2-bound nickel key intermediates.

Herein, we have developed a novel aggregation-induced emission (AIE) probe and three-dimensional (3D) printed portable device for copper (Cu2+) sensing in an aqueous medium. A ubiquitous synthetic route has been employed to devise the anthracene-conjugated imidazo[1,5-a]pyridine (TL19) probe as a unique anchor for Cu2+ ions. The TL19 is meticulously characterized through pivotal spectroscopic techniques, and the satisfactory results were obtained. The solvatochromic analysis and density functional theory calculations cohesively reveal that the TL19 exhibits the intramolecular charge transfer transition upon photoexcitation. Intriguingly, the TL19 exhibits spherically shaped nanoaggregates and enhanced fluorescence in DMSO/water (10:90) mixtures. This fluorescent nanoaggregate instantaneously responded toward the detection of Cu2+ via a deaggregation mechanism. The detection limit is found to be 9 pM in an aqueous medium. Further, the detection of Cu2+ in the HeLa cells has also been achieved due to bright green fluorescence, photostability, and biocompatibility nature of TL19 aggregates. On the other hand, an internet of things (IoT)-embedded 3D printed portable device is constructed for the detection of Cu2+ ions in real water samples. The Cu2+ detection is achieved through an IoT device, and results were acknowledged through an android application in 3.32 s round-trip time. Thus, the IoT-enabled AIE probe could be a prospective device for Cu2+ detection in a constrained environment.

A series of bioinspired copper(II) complexes of N4-tripodal and sterically crowded diazepane-based ligands have been investigated as catalysts for functionalization of the aromatic C-H bond. The tripodal-ligand-based complexes exhibited distorted trigonal-bipyramidal (TBP) geometry (τ, 0.70) around the copper(II) center; however, diazepane-ligand-based complexes adopted square-pyramidal (SP) geometry (τ, 0.037). The Cu-NPy bonds (2.003-2.096 A) are almost identical and shorter than Cu-Namine bonds (2.01-2.148 A). Also, their Cu-O (Cu-Owater, 1.988 A; Cu-Otriflate, 2.33 A) bond distances are slightly varied. All of the complexes exhibited Cu2+ → Cu+ redox couples in acetonitrile, where the redox potentials of TBP-based complexes (-0.251 to -0.383 V) are higher than those of SP-based complexes (-0.450 to -0.527 V). The d-d bands around 582-757 nm and axial patterns of electron paramagnetic resonance spectra [g∥, 2.200-2.251; A∥, (146-166) × 10-4 cm-1] of the complexes suggest the existence of five-coordination geometry. The bonding parameters showed K∥ > K⊥ for all complexes, corresponding to out-of-plane π bonding. The complexes catalyzed direct hydroxylation of benzene using 30% H2O2 and afforded phenol exclusively. The complexes with TBP geometry exhibited the highest amount of phenol formation (37%) with selectivity (98%) superior to that of diazepane-based complexes (29%), which preferred to adopt SP-based geometry. Hydroxylation of benzene likely proceeded via a CuII-OOH key intermediate, and its formation has been established by electrospray ionization mass spectrometry, vibrational, and electronic spectra. Their formation constants have been calculated as (2.54-11.85) × 10-2 s-1 from the appearance of an O (π*σ) → Cu ligand-to-metal charge-transfer transition around 370-390 nm. The kinetic isotope effect (KIE) experiments showed values of 0.97-1.12 for all complexes, which further supports the crucial role of Cu-OOH in catalysis. The 18O-labeling studies using H218O2 showed a 92% incorporation of 18O into phenol, which confirms H2O2 as the key oxygen supplier. Overall, the coordination geometry of the complexes strongly influenced the catalytic efficiencies. The geometry of one of the CuII-OOH intermediates has been optimized by the density functional theory method, and its calculated electronic and vibrational spectra are almost similar to the experimentally observed values.

Herein, we have developed a tool for monitoring the outdoor performance of dye-sensitized solar cells. In this regard, a new dye consisting of an N-aryl-substituted imidazole with N-alkylated carbazole as the donor and cyanoacrylic acid as the acceptor has been designed. The overall power conversion efficiency of the designed dye reached ∼50%, with respect to that of the N719-based device (4%) under similar experimental conditions. Further, the device was interfaced with an IoT system, which measured the voltage and transmitted the device parameters to the user's mobile phone through a cloud channel. The developed IoT tool provides a resolution of 0.0315 mV and a round-trip delay time of

The cobalt(II) complexes of 4N tetradentate ligands have been synthesized and characterized as the catalysts for phenol synthesis in a single step. The molecular structure of the complexes showed a geometry in between square pyramidal and trigonal bipyramidal (τ, 0.49–0.88) with Co–Namine and Co–NPy bond distances of 2.104–2.254 A and 2.043–2.099 A, respectively. The complexes exhibited a Co2+/Co3+ redox potential around 0.489–0.500 V vs. Ag/Ag+ in acetonitrile. The complexes catalyzed hydroxylation of benzene using H2O2 (30%) and afforded phenol selectively as the major product. A maximum yield of phenol up to 29% and turnover number (TON) of 286 at 60 °C, and a yield of 19% and TON of 191 at 25 °C are achieved. This is the highest catalytic performance reported using cobalt(II) complexes as catalysts to date. This aromatic hydroxylation presumably proceeded via a cobalt(III)-hydroperoxo species, which was characterized by ESI-MS, and vibrational and electronic spectral methods. The formation of key intermediate [(L)CoIII(OOH)]2+ was accompanied by the appearance of the characteristic O → Co(III) ligand to metal charge transfer (LMCT) transition around 488–686 nm and vibration modes at 832 cm−1 (O–OH) and 564 cm−1 (Co–O). The geometry of one of the catalytically active intermediates was optimized by DFT and its spectral properties were calculated by TD-DFT calculations. These data are comparable to the experimental observations. The kinetic isotope effect (KIE) values (0.98–1.07) support the involvement of cobalt-bound oxygen species as a key intermediate. Isotope-labeling experiments using H218O2 showed an 89% incorporation of 18O, revealing that H2O2 is the main oxygen supplier for phenol formation from benzene. The catalytic efficiencies of cobalt complexes are tuned by ligand architectures via their geometrical configurations and steric properties.

Platelets play a crucial role in cardiovascular disorders (CVDs); thus, development of a therapeutic target that prevents platelet activation reduces CVDs. Pterostilbene (PTE) has several remarkable pharmacological activities, including anticancer and neuroprotection. Herein, we examined the inhibitory mechanisms of PTE in human platelets and its role in the prevention of vascular thrombosis in mice. At very low concentrations (1-5 μmol/L), PTE strongly inhibited collagen-induced platelet aggregation, but it did not have significant effects against thrombin and 9,11-dideoxy-11α,9α-epoxymethanoprostaglandin (U46619). PTE markedly reduced P-selectin expression on isolated α-granules by a novel microchip. Moreover, PTE inhibited adenosine triphosphate (ATP) release, intracellular ([Ca2+]i) mobilization (resting, 216.6 ± 14.0 nmol/L; collagen-activated platelets, 396.5 ± 25.7 nmol/L; 2.5 μmol/L PTE, 259.4 ± 8.8 nmol/L; 5 μmol/L PTE, 231.8 ± 9.7 nmol/L), phospholipase C (PLC)γ2/protein kinase C (PKC), Akt, and mitogen-activated protein kinase (MAPK) phosphorylation. Neither 9-(tetrahydro-2-furanyl)-9H-purin-6-amine (SQ22536) nor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) reversed platelet aggregation inhibited by PTE. PTE did not affect vasodilator-stimulated phosphoprotein phosphorylation. In mice, PTE obviously reduced the mortality (from 100 to 37.5%) associated with acute pulmonary thromboembolism without increasing the bleeding time. Thus, PTE could be used to prevent CVDs.

Activation of CO2 and conversion into value-added products is an effective option to mitigate CO2 emission. The nickel(II) complexes [Ni(L1)](ClO4)2 1, [Ni(L2)](ClO4)2 2, and [Ni(L3)(CH3CN)2](Ph4B)...

A series of mixed-ligand Cu(II) complexes of the type: (i) [Cu(l-pro)(diimine)(H2O)n](ClO4) (n = 0 or 1), where l-pro is l-proline and diimine is 2,2′-bipyridine (bpy; 1), (ii) 4,4′-dimethy...

Lytic polysaccharide monooxygenases (LPMOs) are copper-containing monooxygenase and catalyzing the oxidative cleavage of recalcitrant polysaccharides using dioxygen. The copper(II) complexes [Cu(L1)(H2O)ClO4]ClO4 1, [L1 = 4-methyl-1-[(pyridin-2-yl-methyl)]-1,4-diazepane]; [Cu(L2)(H2O)ClO4]ClO4 2, [L2 = 4-methyl-1-[(2-(pyridine-2-yl)ethyl]-1,4-diazepane] and [Cu(L3)(H2O)ClO4]ClO4 3, [L3 = 1-(4-methoxy-3,5-dimethyl-pyridin-2-yl)methyl)-4-methyl-1,4-diazepane] have been synthesized and characterized as the novel models for LPMOs. The molecular structures exhibit distorted square pyramidal geometry (τ, 0.183–0.388) as similar to LPMOs. The Cu N (1.99–2.02 A) bond distances of the model complexes are almost identical to those of native LPMOs enzyme (1.9–2.2 A). The 1, 4-diazepane backbone and pyridine unit of complexes provide reasonable structural resemblances to ‘histidine brace’ and histidine residues of LPMOs respectively. The spectral, redox and kinetic studies were performed in water to mimic accurate enzymatic reaction conditions. The well-defined Cu(II)/Cu(I) reduction couples were observed around 8–112 mV versus NHE, which is lower than that of LPMOs. The electronic spectra of the complexes showed the d-d transitions around 600–635 nm and axial EPR parameter (g||, 2.28–2.29; A||, 160–168 × 10−4 cm−1), which are almost identical to that of LPMOs. The model complexes were catalyzed oxidative cleavage of model substrate p-nitrophenyl-β-D-glucopyranoside into p-nitrophenol and D-allose with a maximum yield up to 78.4% and TON, 300. The kinetics of reaction monitored by following the formation of an absorption band around at 400 nm corresponds to p-nitrophenol, showed the rate of 3.19–5.26 × 10−3 s−1. The oxidative cleavage reaction may occur via CuII-OOH intermediate, whose formation accompanied by an electronic spectral signature around 375 nm with the rate of 1.61–9.06 × 10−3 s−1. The CuII-OOH intermediate was characterized by spectral methods and its geometry was optimized by DFT calculations.

Overexpression of cysteine cathepsins proteases has been documented in a wide variety of cancers, and enhances the l-cysteine concentration in tumor cells. We report the synthesis and characterization of copper(ii) complexes [Cu(L1)2(H2O)](SO3CF3)2, 1, L1 = 3-phenyl-1-(pyridin-2-yl)imidazo[1,5-a]pyridine, [Cu(L2)2(SO3CF3)]SO3CF3, 2, L2 = 3-(4-methoxyphenyl)-1-pyridin-2-yl-imidazo[1,5-a]pyridine, [Cu(L3)2(H2O)](SO3CF3)2, 3, L3 = 3-(3,4-dimethoxy-phenyl)-1-pyridin-2-yl-imidazo[1,5-a]pyridine and [Cu(L4)2(H2O)](SO3CF3)2, 4, L4 = dimethyl-[4-(1-pyridin-2-yl-imidazo[1,5-a]pyridin-3-yl)phenyl]amine as 'turn-on' optical imaging probes for l-cysteine in cancer cells. The molecular structure of complexes adopted distorted trigonal pyramidal geometry (τ, 0.68-0.87). Cu-Npy bonds (1.964-1.989 A) were shorter than Cu-Nimi bonds (2.024-2.074 A) for all complexes. Geometrical distortion was strongly revealed in EPR spectra, showing g‖ (2.26-2.28) and A‖ values (139-163 × 10-4 cm-1) at 70 K. The d-d transitions appeared around 680-741 and 882-932 nm in HEPES, which supported the existence of five-coordinate geometry in solution. The Cu(ii)/Cu(i) redox potential of 1 (0.221 V vs. NHE) was almost identical to that of 2 and 3 but lower than that of 4 (0.525 V vs. NHE) in HEPES buffer. The complexes were almost non-emissive in nature, but became emissive by the interaction of l-cysteine in 100% HEPES at pH 7.34 via reduction of Cu(ii) to Cu(i). Among the probes, probe 2 showed selective and efficient turn-on fluorescence behavior towards l-cysteine over natural amino acids with a limit of detection of 9.9 × 10-8 M and binding constant of 2.3 × 105 M-1. The selectivity of 2 may have originated from a nearly perfect trigonal plane adopted around a copper(ii) center (∼120.70°), which required minimum structural change during the reduction of Cu(ii) to Cu(i) while imaging Cys. The other complexes, with their distorted trigonal planes, required more reorganizational energy, which resulted in poor selectivity. Probe 2 was employed for optical imaging of l-cysteine in HeLa cells and macrophages. It exhibited brighter fluorescent images by visualizing Cys at pH 7.34 and 37 °C. It showed relatively less toxicity for these cell lines as ascertained by the MTT assay.

Nickel(II)complexes of N4-ligands have been synthesized and characterized as efficient catalysts for the hydroxylation of benzene using H2O2. All the complexes exhibited Ni2+ → Ni3+ oxidation potentials of around 0.966–1.051 V vs. Ag/Ag+ in acetonitrile. One of the complexes has been structurally characterized and adopted an octahedral coordination geometry around the nickel(II) center. The complexes catalysed direct benzene hydroxylation using H2O2 as an oxygen source and afforded phenol up to 41% with a turnover number (TON) of 820. This is unprecedentedly the highest catalytic efficiency achieved to date for benzene hydroxylation using 0.05 mol% catalyst loading and five equivalents of H2O2. The benzene hydroxylation reaction possibly proceeds via the key intermediate bis(μ-oxo)dinickel(III) species, which was characterized by HR-MS, vibrational and electronic spectral methods, for almost all complexes. The formation constant of the key intermediate was calculated to be 5.61–9.41 × 10−2 s−1 by following the appearance of an oxo-to-Ni(III) LMCT band at around 406–413 nm. The intermediates are found to be very short-lived (t1/2, 73–123 s). The geometry of one of the catalytically active intermediates was optimized by DFT and its spectral properties were calculated by TD-DFT calculations, which are comparable to experimental spectral data. The kinetic isotope effect (KIE) values (0.98–1.05) support the involvement of nickel-bound oxygen species as an intermediate. The isotope-labeling experiments using H218O2 showed 92.46% incorporation of 18O, revealing that H2O2 is the key oxygen supplier to form phenol. The catalytic efficiencies of complexes are strongly influenced by the geometrical configuration of intermediates, and stereoelectronic and steric properties, which are fine-tuned by the ligand architecture.

Four novel N-heterocyclic carbene (NHC) based Fe(II) complexes, [Fe(L1)Cp(CO)]I (1), [L1 = 3-methyl-1-(pyridin-2-ylmethyl)-benzimidazol-2-ylidene], [Fe(L2)Cp(CO)]Br (2) [L2 = 3-benzyl-1-(pyridin-2-ylmethyl)-benzimidazol-2-ylidene], [Fe(L3)Cp-(CO)]Br (3), [L3 = 3-(4-tert-butyl-benzyl)-1-(pyridin-2-ylmethyl)-benzimidazol-2-ylidene] and [Fe(L4)Cp(CO)]I (4), L4 = 1,3-di-(2- methylenepyridyl methyl)-benzimidazol-2-ylidene] have been synthesized and characterized as efficient catalysts for transfer hydrogenation of carbonyl compounds. The disappearance of 1H NMR signals at 10.09–11.78 ppm of NHC ligand confirms the complex formation via carbene coordination to low spin Fe(II) center and it is further supported by the two distinct doublets for two diastereotopic protons of the methylene group connects pyridine and benzimidazole rings. The IR spectra show νstr, 1939–1958 cm−1 for the coordinated CO, which are virtually independent of the wingtip substituents and possibly this limits the influence of those groups on the electronic properties of iron(II) center. The molecular structure of the complexes 1, 2 and 4 reveals the coordination of NHC ligand, cyclopentadiene (Cp) and CO to low spin FeII center (S = 0). The bonds Fe-Ccarbene (1.907–1.934 A), Fe-NPy (1.995–2.019 A), Fe−CO (1.743–1.762 A) and Fe-Cp (2.058–2.097 A) are almost identical in all the complexes. The bite angles CO-Fe-Ccarbene (90.9°– 113.8°) are higher than Cp-Fe-Ccarbene (92.6°–93.2°) but the bite angle CO-Fe-Npy are merely indentical in all complexes (89.7°). All the complexes showed two redox couples at 1.050 - 1.080 V and 0.560 – 0.585 V corresponds to FeII/FeIII and ligand-based redox couples respectively. The complexes exhibited the excellent transfer hydrogenation for aldehydes up to yield of 99% with the turnover frequency (TOF) of 13,680 h−1 at room temperature. The ketone substrates showed conversion of alcohols with the yield and TOF of 98% and 2264 h−1 respectively at 60 °C.

The title compound bis[2-hydroxybenzylidenehydrazono)(methylthio)methyl]disulfide (1), an S-methyldithiocarbazate derivative with a disulfide bond has been synthesized by the condensation of 2-hydroxybenzaldehyde with S-methyldithiocarbazate. It has been characterized by elemental analyses, 1H, 13C NMR and FT-IR spectroscopy and mass spectrometry. The single crystal X-ray structure shows that the compound exists in a tautomeric thione form with the dithiocarbazate fragment adopting an EE configuration with respect to the C=N bond of the benzylidene moiety. The thermal behaviour of the compound has been studied using thermogravimetric analysis (TGA). The molecular geometry of the compound in the ground state has been optimized using density functional theory (DFT/B3LYP) method with the 6-311++G(d,p) basis sets. Molecular docking of the compound with human carbonic anhydrase II has been performed to probe the nature of interaction.

A new pyrene Schiff base (KB-4) was synthesized and demonstrated as simple colorimetric chemosensor for carbon dioxide (CO2) gas activated by fluoride anion. The chemical structure of KB-4 was validated through pivotal characterization methods. A combined quantum chemical calculations and spectroscopic techniques were adopted to understand the photophysical properties of KB-4. The sensitivity of KB-4 chemosensor towards various anions is investigated and showed excellent selectivity towards F− anion with a distinct color change. The mechanism of F− anion sensing is due to the complete deprotonation of –NH proton in KB-4 as revealed by 1H NMR titration studies as well as DFT calculations. Subsequently, the in-situ deprotonated KB-4 is employed for CO2 gas sensing. Interestingly, deprotonated KB-4 is responded instantaneously to CO2 gas by exhibiting significant colorimetric and fluorimetric changes with a detection limit of 0.4 ml. Further, digital image based RGB analysis using smartphone is introduced for detection of CO2 gas. The digital images of CO2 gas induced fluorimetric changes are captured using smartphone and the RGB analysis of the images are processed using MATLAB. The intensity variation in the color components as an indicative measure for detection of CO2 gas is demonstrated.

The copper(II) complexes [Cu(L)NO

Background Columbianadin (CBN) is one of the main coumarin constituents isolated from Angelica pubescens. The pharmacological value of CBN is well demonstrated, especially in the prevention of several cancers and analgesic activity. A striking therapeutic target for arterial thrombosis is inhibition of platelet activation because platelet activation significantly contributes to these diseases. The current study examined the influence of CBN on human platelet activation in vitro and vascular thrombotic formation in vivo. Methods Aggregometry, immunoblotting, immunoprecipitation, confocal microscopic analysis, fibrin clot retraction, and thrombogenic animals were used in this study. Results CBN markedly inhibited platelet aggregation in washed human platelets stimulated only by collagen, but was not effective in platelets stimulated by other agonists such as thrombin, arachidonic acid, and U46619. CBN evidently inhibited ATP release, intracellular ([Ca2+]i) mobilization, and P-selectin expression. It also inhibited the phosphorylation of phospholipase C (PLC)γ2, protein kinase C (PKC), Akt (protein kinase B), and mitogen-activated protein kinases (MAPKs; extracellular signal-regulated kinase [ERK] 1/2 and c-Jun N-terminal kinase [JNK] 1/2, but not p38 MAPK) in collagen-activated platelets. Neither SQ22536, an adenylate cyclase inhibitor, nor ODQ, a guanylate cyclase inhibitor, reversed the CBN-mediated inhibition of platelet aggregation. CBN had no significant effect in triggering vasodilator-stimulated phosphoprotein phosphorylation. Moreover, it markedly hindered integrin αIIbβ3 activation by interfering with the binding of PAC-1; nevertheless, it had no influences on integrin αIIbβ3-mediated outside-in signaling such as adhesion number and spreading area of platelets on immobilized fibrinogen as well as thrombin-stimulated fibrin clot retraction. Additionally, CBN did not attenuate FITC-triflavin binding or phosphorylation of proteins, such as integrin β3, Src, and focal adhesion kinase, in platelets spreading on immobilized fibrinogen. In experimental mice, CBN increased the occlusion time of thrombotic platelet plug formation. Conclusion This study demonstrated that CBN exhibits an exceptional activity against platelet activation through inhibition of the PLCγ2-PKC cascade, subsequently suppressing the activation of Akt and ERKs/JNKs and influencing platelet aggregation. Consequently, this work provides solid evidence and considers that CBN has the potential to serve as a therapeutic agent for the treatment of thromboembolic disorders.

Activated microglia are crucial in the regulation of neuronal homeostasis and neuroinflammation. They also contribute to neuropathological processes after ischemic stroke. Thus, finding new approaches for reducing neuroinflammation has gained considerable attention. The metal ruthenium has gained notable attention because of its ability to form new complexes that can be used in disease treatment. [Ru(&eta, 6-cymene)2-(1H-benzoimidazol-2-yl)-quinoline Cl]BF4 (TQ-6), a potent ruthenium (II)-derived compound, was used in this study to investigate its neuroprotective action against microglia activation, middle cerebral artery occlusion (MCAO)-induced embolic stroke, and platelet activation, respectively. TQ-6 (2 &mu, M) potently diminished inflammatory mediators (nitric oxide/inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2)) expression, nuclear factor kappa B (NF-&kappa, B) p65 phosphorylation, nuclear translocation, and hydroxyl radical (OH&bull, ) formation in LPS-stimulated microglia. Conversely, TQ-6 increased the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). Moreover, it significantly reduced brain infarct volume and edema in MCAO mice. Additionally, it drastically inhibited platelet aggregation and OH&bull, production in mice platelets. This study confirmed that TQ-6 exerts an anti-neuroinflammatory effect on microglia activation through neuroprotection, antiplatelet activation, and free radical scavenging. The authors propose that TQ-6 might mitigate neurodegenerative pathology by inhibiting the NF-&kappa, B-mediated downstream pathway (iNOS and COX-2) and enhancing Nrf2/HO-1 signaling molecules in microglia.

The title compound bis[2-hydroxybenzylidenehydrazono)(methylthio)methyl]disulfide ( 1 ), an S-methyldithiocarbazate derivative with a disulfide bond has been synthesized by the condensation of 2-hydroxybenzaldehyde with S-methyldithiocarbazate. It has been characterized by elemental analyses, 1 H, 13 C NMR and FT-IR spectroscopy and mass spectrometry. The single crystal X-ray structure shows that the compound exists in a tautomeric thione form with the dithiocarbazate fragment adopting an EE configuration with respect to the C=N bond of the benzylidene moiety. The thermal behaviour of the compound has been studied using thermogravimetric analysis (TGA). The molecular geometry of the compound in the ground state has been optimized using density functional theory (DFT/B3LYP) method with the 6-311++G(d,p) basis sets. Molecular docking of the compound with human carbonic anhydrase II has been performed to probe the nature of interaction.

D−π–A, D–A−π–A, and other configuration-based organic dyes have shown great potential in the field of dye-sensitized solar cells (DSCs). Compared with traditional configurations, D–D′–A offers several advantages such as enrichment of the electron-donating ability, absorption spectral region, and molar extinction coefficient and inhibits dye aggregation. Hence, in this work, a novel D–D′–A-type dye has been designed and synthesized for DSC applications. In this configuration, substituted imidazole has been used as a primary donor, phenothiazine as an auxiliary donor, and cyanoacetic acid as an acceptor/anchoring group. Structural characterizations of a D–D′–A-type dye were done by using NMR and electron ionization–mass spectrometry. Photophysical, electrochemical, and computational studies were systematically performed to evaluate its electronic transitions, light-harvesting property, highest occupied molecular orbital (HOMO)/lowest unoccupied molecular orbital (LUMO) levels, and redox behavior. The photop...

Platelet activation has been reported to play a major role in arterial thrombosis, cancer metastasis, and progression. Recently, we developed a novel Ir(III)-based compound, [Ir(Cp∗)1-(2-pyridyl)-3-(4-dimethylaminophenyl)imidazo[1,5-a]pyridine Cl]BF4or Ir-6 and assessed its effectiveness as an antiplatelet drug. Ir-6 exhibited higher potency against human platelet aggregation stimulated by collagen. Ir-6 also inhibited ATP-release, intracellular Ca2+mobilization, P-selectin expression, and the phosphorylation of phospholipase Cγ2 (PLCγ2), protein kinase C (PKC), v-Akt murine thymoma viral oncogene (Akt)/protein kinase B, and mitogen-activated protein kinases (MAPKs), in collagen-activated platelets. Neither the adenylate cyclase inhibitor SQ22536 nor the guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one significantly reversed the Ir-6-mediated inhibition of collagen-induced platelet aggregation. Moreover, Ir-6 did not considerably diminish OH radical signals in collagen-activated platelets or Fenton reaction solution. At 2 mg/kg, Ir-6 markedly prolonged the bleeding time in experimental mice. In conclusion, Ir-6 plays a crucial role by inhibiting platelet activation through the inhibition of signaling pathways, such as the PLCγ2–PKC cascade and the subsequent suppression of Akt and MAPK activation, thereby ultimately inhibiting platelet aggregation. Therefore, Ir-6 is a potential therapeutic agent for preventing or treating thromboembolic disorders or disrupting the interplay between platelets and tumor cells, which contributes to tumor cell growth and progression.

A mixed ligand complex [cis-Dichloro(2-(2-Pyridyl)benzimidazole) (1H-Imidazole)Copper(II)] (1) has been prepared by the reaction of 2-(2-pyridyl)benzimidazole, 1H-imidazole with copper(II)chloride in ethanol medium. The structure of 1 was determined by single crystal X-ray diffraction. The results gives that the complex 1 belongs to monoclinic, space group P21/C with a = 9.3566(19) Å, b = 12.504(3) Å, c = 14.018(3) Å, a = 90°, b = 105.30(3)°, g = 90°, V = 1582.0(6) Å3, Z = 4 and final R1 = 0.0529, ωR2 = 0.07. The complex molecules form 1D chain structure by the H-Cl-H intermolecular hydrogen bond interaction. The complex exhibits trigonal bipyramidal distorted square based pyramidal (TBDSBP) coordination geometry.