Nε-(carboxymethyl)lysine promotes lipid uptake of macrophage via cluster of differentiation 36 and receptor for advanced glycation end products

BACKGROUND Advanced glycation end products(AGEs)are diabetic metabolic toxic products that cannot be ignored.Nε-(carboxymethyl)lysine(CML),a component of AGEs,could increase macrophage lipid uptake,promote foam cell formation,and thereby accelerate atherosclerosis.The receptor for AGEs(RAGE)and cluster of differentiation 36(CD36)were the receptors of CML.However,it is still unknown whether RAGE and CD36 play key roles in CML-promoted lipid uptake.AIM Our study aimed to explore the role of RAGE and CD36 in CML-induced macrophage lipid uptake.METHODS In this study,we examined the effect of CML on lipid uptake by Raw264.7 macrophages.After adding 10 mmol/L CML,the lipid accumulation in macrophages was confirmed by oil red O staining.Expression changes of CD36 and RAGE were detected with immunoblotting and quantitative real-time polymerase chain reaction.The interaction between CML with CD36 and RAGE was verified by immunoprecipitation.We synthesized a novel N-succinimidyl-4-18Ffluorobenzoate-CML radioactive probe.Radioactive receptor-ligand binding assays were performed to test the binding affinity between CML with CD36 and RAGE.The effects of blocking CD36 or RAGE on CML-promoting lipid uptake were also detected.RESULTS The study revealed that CML significantly promoted lipid uptake by macrophages.Immunoprecipitation and radioactive receptor-ligand binding assays indicated that CML could specifically bind to both CD36 and RAGE.CML had a higher affinity for CD36 than RAGE.ARG82,ASN71,and THR70 were the potential interacting amino acids that CD36 binds to CML Anti-CD36 and anti-RAGE could block the uptake of CML by macrophages.The lipid uptake promotion effect of CML was significantly attenuated after blocking CD36 or RAGE.CONCLUSION Our results suggest that the binding of CML with CD36 and RAGE promotes macrophage lipid uptake.

Two-Stage Hydrogenation Modification of C_9 Petroleum Resin over NiWS/γ-Al_2O_3 and PdRu/γ-Al_2O_3 Catalysts in Series

Hydrogenation modification is one of the most important ways to produce high-quality petroleum resin. The col- orless C9 petroleum resin （CgPR） was obtained by two-stage catalytic hydrogenation over NiWS/？-A1203 catalyst and PdRu/ y-A1203 catalyst connected in series. Via the hydrogenation reaction, aromatic rings in C9PR were converted to alicyclic rings, and its color was reduced from Gardner color grade No. 11 to Gardner color grade No. 0. The optimum Ni/W atomic ratio was found to be close to 0.23, while the optimum Pd/Ru atomic ratio was close to 3.80. The TEM results showed that the morphology and size of sulfide or metal particles of the two kinds of catalysts remained almost unchanged after the reac- tion was carried our for 1 204 hours, attesting to their good catalytic stability.

Enantioselective Hydrogenation of Ethyl 2-Oxo-4-phenylbutyrate on Cinchona-Platinum Catalysts

Enantioselective hydrogenation of ethyl 2-oxo-4-phenylbutyrate to ethyl （R）-2-hydroxy-4-phenyl- bu- tyrate on Pt/γ-Al2O3 modified by 10,11-dihydrocinchonidine was studied by investigating the influences of the amount of modifier, initial concentration of reactant, pressure and temperature on conversion and enantiometric excess in a stirred autoclave and the effects of the liquid velocity, gas velocity, modifier concentration and various catalytic beds in a trickle-bed reactor. The maximum optical yields were about 50% and 60% in the two types of reactors, respectively. It was assumed that the total hydrogenation rate included the reaction rates over the unmodified and modified active sites on platinum surface and a kinetic model, which fitted the experimental data well in autoclave, was obtained. A simplified plug-flow model was proposed to describe the bed average efficiency of trickle-bed reactor.

Asymmetric Hydrogenation Synthesis of (S)-(+)-2-(6′-methoxyl-2-naphthyl) propionic Acid by Cinchona Modified Pd(0)-α-FeOOH Catalyst

Asymmetric hydrogenation of (6-methoxyl-2-naphthyl)-2-acrylic acid catalyzed by cinchona modified Pd(0)-a-FeOOH was reported and ee抯 of (S)-(+)-2-(6′-methoxyl-2-naphthyl) propionic acid ((S)-(+)-naproxen) up to 98% was achieved firstly.

A New Cadmium(Ⅱ) Coordination Polymer Extended through Hydrogen Bonds and π-π Stacking Interactions: Synthesis and Photoluminescence Property

A new coordination polymer, {[Cd(OPY)(tdc)(HO)]·H2 O}n(OPY = 4,4?-(oxybis(4,1-phenylene))dipyridine, H2 tdc = thiophene-2,5-dicarboxylic acid), has been synthesized hydrothermally based on a V-shaped ligand OPY. The structure was fully characterized by elemental analysis, FT-IR spectroscopy, and X-ray single-crystal diffraction analysis. In1, two OPY ligands and one water molecule acted as terminal ligands coordinating to Cdcation to form [Cd(OPY)HO]units, which are then linked by tdc2-ligands to generate a one-dimensional chain. Every two adjacent chains linked by extensive O–H···O hydrogen bonds constitute one-dimensional double-chains, and such chains are extended into two-dimensional layers via O–H···N hydrogen bonds. These layers are further connected to form a three-dimensional supramolecular architecture via π-π stacking interactions. In addition, the thermal stability and solid state fluorescence property of 1 were also investigated.

PREPARATION,CHARACTERIZATION AND HYDROGENATION PROPERTY OF POLYMER-SUPPORTED Pd-Fe_2O_3 COMPOSITE CATALYSTS

A series of polymer- supported Pd -Fe2O3 composite catalysts were prepared and their hydrogenation property mas investigated. It was found that the above catalysts have good catalytic hydrogenation activity for carbon - carbon double bonds systems and reusability. Furthermore, XPS and IR spectra shouted that active component in the composite catalysts is atomic Pd(0). An addition of a small amount of Fe2O3 has a promotive action upon hydrogenation activity of the catalysts, which indicated that there are some strong interactions (electron transfer) between Pd(0) and Fe(Ⅲ) species. Based on these results, a possible catalytic hydrogenation mechanism was also suggested.

Synthesis of Novel C_(2)-Symmetrical Bidentate Phosphoramidite Ligands for Rh-catalyzed Asymmetric Hydrogenation of β-(Acylamino)acrylates

Two new C2-symmetrical bidentate phosphoramidite ligands were synthesized and employed in the Rh-catalyzed asymmetric hydrogenation of β-（acylamino）acrylates, up to 89% ee with full conversions was obtained.

Synthesis of Agomelatine by One-pot Catalytic Hydrogenation and Acetylation with NiO

Nano-NiO and bulk NiO were prepared from Ni(AC)_2·4 H_2O by coordination precipitation using aqueous ammonia and by a solid state reaction, respectively. The nickel oxide particles were characterized by X-ray Diffraction(XRD) and scanning electron microscopy(SEM). The results indicate that nano-sized NiO has a crystal phase with a standard face-centered cubic lattice structure, with a mean particle diameter of about 10 nm. The evaluation of the activity of nickel oxide nanoparticles in the catalytic hydrogenation of 7-methoxy-1-naphthylacetonitrile was carried out. The results demonstrate the efficient synthesis of the title compound by a one-pot catalytic hydrogenation and acetylation with NiO. The NiO nanoparticles displayed superior catalytic activity in the synthesis of agomelatine in the one-pot reaction.The total yield of agomelatine is over 81.8% with a purity of 99.2%, as determined by HPLC. The structure of agomelatine was confirmed by IR, MS, and 1 H NMR analysis.

The Protective Effects of N-Acetylcysteine on Exogenous Hydrogen Peroxide and Endogenous Superoxide Anion-induced DNA Strand Breakage in Human Spermatozoa

Objective To explore the protective effects of N Acetylcysteine (NAC) on exogenous hydrogen peroxide and endogenous superoxide anion induced DNA strand breakage in human spermatozoa by using the single cell gel electropherosis (SCGE) Methods Sperm cells were exposed to 0.5 mmol/L of H 2O 2 or 5.0 mmol/L of β NADPH with or without 0.1, 0.5, 1.0 mmol/L of NAC. The percentage of sperm comet cells and the comet tail lengths were measured in the treated sperm cells by using SCGE. Results Both percentage of comet sperm nuclei and mean tail length in sperm cells exposed to 0.5 mmol/L hydrogen peroxide with different concentrations of NAC decrease significantly in a dose dependent manner as compared with sperm cells exposed to H 2O 2 without NAC or catalase. Although mean tail length in sperm cells exposed to 5.0 mmol/L of β NADPH with different concentrations of NAC decreases significantly compared with sperm cells exposed to β NADPH without NAC or SOD, there were no significant differences on the percentage of sperm comet cells between sperm cells exposed to 5.0 mmol/L of β NADPH with different concentrations of NAC and sperm cells exposed to 5.0 mmol/L of β NADPH without NAC. Conclusion NAC has a protective effect on exogenous hydrogen peroxide induced DNA damage, while protective effect of NAC against O - 2 induced DNA strand breakage is significant but very weak.

Involvement of ERK1/2 and p38 MAPK in up-regulation of 14-3-3 protein induced by hydrogen peroxide preconditioning in PC12 cells

Objective To investigate the protective effects of hydrogen peroxide preconditioning （HPP） on the pheochromocytoma （PC12） cells treated with 1-methyl-4-phenylpyridinium （MPP^＋） and to explore the potential mechanisms. Methods The viability and apoptosis of PC 12 cells were determinded by 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay and 4′,6′-diamidino-2-phenylindole （DAPI） staining, respectively. The expressions of 14-3-3 protein and phospholylated p38 mitogen-activated protein kinase （MAPK） were determined by Western blot. Enzyme-linked immunosorbent assay （ELISA） was used to measure the activity of extracellular signal-regulated protein kinase 1/2 （ERK1/2）. Results The cell viability decreased and the number of apoptotic cells increased dramatically in MPP^＋ group compared with that in Control group. HPP induced a significant increase in cell viability and a marked decrease in population of apoptotic cells of the MPP^＋- treated PC 12 cells, accompanied with up-regulation of 14-3-3 protein and increase of ERK 1/2 and p38 MAPK activities. The 14-3-3 protein expression was positively correlated with the phosphorylation of ERK1/2. Furthermore, inhibition of the ERK1/2 with PD98059 abolished the 14-3-3 protein up-regulation in PC 12 cells induced by HPP. Conclusion HPP protects PC 12 cells against MPP＋ toxicity by up-regulating 14-3-3 protein expression through the ERK1/2 and p38 MAPK signaling pathways.

Asymmetric Transfer Hydrogenation of Stable NH Imines for the Synthesis of Enantiopure α-Chiral Primary Amines

Although it offers a direct route to access synthetically valuableα-chiral primary amines,asymmetric transfer hydrogenation of NH imines has been rarely studied,due in large part to the inaccessibility and instability of NH imines.Herein,we report a Rh-catalyzed asymmetric transfer hydrogenation of a kind of novel and stable NH imines which are prepared via condensation of easily available sulfonylated 2'-aminoacetophenones with NH3 in methanol.With this method,enantioenriched chiral 2-(1-aminoalkyl)anilines,which are privileged pharmacore groups,have been synthesized with good functional group compatibility,and with up to 99%ee.A gram-scale reaction using 0.2 mol%of catalyst has been successfully performed to highlight the practicality.Furthermore,the products can be derivatized into enantiopure bioactive molecules as well as chiral tridentate ligands for metal catalysis.

π-π Stacking, Hydrogen Bonding and Magnetic Coupling Mechanism on a Mono-nuclear Cu^Ⅱ Complex

A new mono-nuclear CuII complex [Cu（DPP）（DP）Br]（ClO4）H2O （DPP = 2-（3,5- dimethyl-1H-pyrazol-1-yl）-1,10-phenanthroline, DP = 3,5-dimethyl-1H-pyrazole） has been syn- thesized with 2-（3,5-dimethyl-1H-pyrazol-1-yl）-1,10-phenanthroline and 3,5-dimethyl-1H-pyrazole as ligands, and its crystal structure was determined by X-ray crystallography. The crystal is of monoclinic system, space group P21/c with a = 13.765（2）, b = 17.044（3）, c = 10.9044（16）, β= 97.112（2）°, V = 2538.5（6）3, Z = 4, C22H24BrClCuN6O5, Mr = 631.37, Dc = 1.652 g/cm3, F（000） = 1276 and μ= 2.585 mm-1. In the crystal, DPP functions as a tridentate ligand and CuII ions assume a distorted square pyramidal geometry with Br atom lying on the apex, and at the same time, there is π-π stacking between adjacent complexes, which deals with two 1,10-phenanthroline plane rings. In addition to the π-π stacking, there are C-H···Br non-classic hydrogen bonds between adjacent complexes. The theoretical calculations reveal that the π-π stacking and C-H···Br non-classic hydrogen bond result in a weak anti-ferromagnetic interaction with 2J = -5.34 cm-1 and a weak ferromagnetic 2J = 5.92 cm-1, respectively. The magnetic coupling sign from the π-π stacking could be explained with McConnell I spin-polarization mechanism.

Endozepine-4 levels are increased in hepatic coma

AIM:To evaluate the serum levels of endozepine-4,their relation with ammonia serum levels,the grading of coma and the severity of cirrhosis,in patients with hepatic coma. METHODS:In this study we included 20 subjects with Hepatic coma,20 subjects with minimal hepatic encephalopathy(MHE) and 20 subjects control. All subjects underwent blood analysis,Child Pugh and Model for End- stage liver disease(MELD) assessment,endozepine-4 analysis. RESULTS:Subjects with hepatic coma showed significant difference in endozepine-4(P < 0.001) and NH3 levels(P < 0.001) compared both to MHE and controls patients. Between NH3 and endozepine-4 we observed a significant correlation(P = 0.009; Pearson correlation 0.570). There was a significant correlation between endozepine-4 and MELD(P = 0.017; Pearsoncorrelation = 0.529). In our study blood ammonia concentration was noted to be raised in patients with hepatic coma,with the highest ammonia levels being found in those who were comatose. We also found a high correlation between endozepine-4 and ammonia(P < 0.001). In patients with grade Ⅳ hepatic coma,endozepine levels were significantly higher compared to other groups. CONCLUSION:This study suggests that an increased level of endozepine in subjects with higher levels of MELD was observed. In conclusion,data concerning involvement of the GABA-ergic system in HE coma could be explained by stage-specific alterations.

Highly enhanced visible-light photocatalytic hydrogen evolution on g-C_3N_4 decorated with vopc through π-π interaction

Photocatalytic H2 evolution reactions on pristine graphitic carbon nitrides(g-C3N4),as a promising approach for converting solar energy to fuel,are attractive for tackling global energy concerns but still suffer from low efficiencies.In this article,we report a tractable approach to modifying g-C3N4 with vanadyl phthalocyanine(VOPc/CN)for efficient visible-light-driven hydrogen production.A non-covalent VOPc/CN hybrid photocatalyst formed viaπ-πstacking interactions between the two components,as confirmed by analysis of UV-vis absorption spectra.The VOPc/CN hybrid photocatalyst shows excellent visible-light-driven photocatalytic performance and good stability.Under optimal conditions,the corresponding H2 evolution rate is nearly 6 times higher than that of pure g-C3N4.The role of VOPc in promoting hydrogen evolution activity was to extend the visible light absorption range and prevent the recombination of photoexcited electron-hole pairs effectively.It is expected that this facile modification method could be a new inspiration for the rational design and exploration of g-C3N4-based hybrid systems with strong light absorption and high-efficiency carrier separation.

Preparation, Structure and Properties of 3D Supramolecular Architecture, on the Basis of Hydrogen Bonds and π-π Stacking Between 2D Layers, with Windmill Building Blocks

A novel three-dimensional（3D） supramolecular architecture, {[Nd（OH-BDC）（OH-HBDC）（H2O）2]·2HaO）n（1） （OH-H2BDC=5-hydroxyisophthalic acid）, which was formed through hydrogen bonds and π-π stacking between two-dimensional（2D） layers, was hydrothermally synthesized and characterized by single-crystal X-ray diffraction. Windmill building blocks, which consist of two nine-coordinated metal centers and four OH-H2BDC groups are connected through two carboxyl groups, to lead to a one-dimensional infinite inorganic chain（… M--O--C--O--M…） along the [100] direction. An observed intense blue luminescence with an emission band peaked at 390 nm for compound 1 may results from ligand-to-metal charge transfer（LMCT）. Variable-temperature magnetic susceptibility of compound 1 was investigated and the value was deviated from the Curie-Weiss law.

Effect of Pyridinecarboxylic Acid on the Molecular Packing Architectures of Disc-shaped 2,3,6,7,10,11-Hexahydroxytriphenylene with Both Large π System and Hydrogen Bond Sites

Co-crystallization of 2,3,6,7,10,11-hexahydroxytriphenylene(L)with nicotinic acid(3-pyaH)and isonicotinic acid(4-pyaH)offers L·(3-pyaH)·5 H2O(1)and L·2(4-pya H)·5 H2O(2),respectively.In 1,each L links three neighboring L molecules via O-H···O and C-H···O hydrogen bonds,furnishing a 1 D chain.The hydrogen bonding and p-p stacking deriving from 3-pyaH and L extend the chains to a 2D layer.Lattice water molecules are interconnected to 3-pyaH via hydrogen bonds into a 1 D[(3-pya H)×5 H2O]￥chain.While in 2,Hydrogen bonding between L and 4-pyaH produces a 2D net with triangle and parallelogram grids.Water molecules locate in interlayer and grids,and O(1 w)and O(2 w)link 4-pyaH into a 1 D[(4-pyaH)×2 H2O]∞ chain.

Hydrogen-bonded Three-Dimensional Networks Encapsulating One-dimensional Covalent Chains: [Cu(3-ampy)(H_2O)_4](SO_4)·(H_2O) (3-ampy = 3-Aminopyridine)

A three-dimensional complex [Cu（3-ampy）（HEO）4]（SO4）·（H2O） （3-ampy = 3-amino- pyridine） has been synthesized. Crystallographic data： C5H16CuN2O9S, Mr = 343.80, triclinic, space group P1, a = 7.675（2）, b = 8.225（3）, c = 10.845（3）A, α= 86.996（4）, β = 76.292（4）, γ= 68.890（4）°, V = 620.0（3）A^3, Z = 2, Dc = 1.841 g/cm^3, F（000） = 354 and μ = 1.971 mm^-1. The structure was refined to R = 0.0269 and wR = 0.0659 for 1838 observed reflections （I 〉 2a（/））. The structure consists of [Cu（3-ampy）（H2O）4]^2＋ cations, SO4^2- anions and lattice water molecules. 3-Ampy acting as a bidentate bridging ligand generates a 1D covalent chain. A supramolecular 2D framework is formed through π-π stacking of pyridine rings. The lattice water molecules and SO4^2- anions are located between the adjacent 2D frameworks. The hydrogen bonding interactions from lattice water molecules and SO4^2- anions to coordinate water extend the 2D framework into a 3D network.

Structure of [Co(im)6]SiF6：Short Hydrogen Bonds Involving SiF62- Ions

A new complex C（18）H（24）CoF6N（12）Si has been synthesized by the reaction of cobalt（II） fluoride tetrahydrate with imidazole in a glass vessel. SiF62-was generated by in situ reaction of fluoride on silica. This complex has been characterized by different techniques such as elemental analysis, IR studies, magnetic measurements, electronic absorption measurements and single-crystal X-ray structure determination. The crystals are hexagonal in the R-3 space group, with a = 13.225（6）, b = 13.225（6）, c = 12.517（11） A, and g = 120°. In complex [Co（im）6]SiF6, the cobalt atom is six-coordinated to adopt a regular octahedral geometry and the SiF62-ion acts as the counter anion. The crystal displays a network structure and SiF62- bridging hexagram formation by N-（39）···F-Si interactions between imdazole and SiF62-. SiF62-plays an important role in assembling the supramolecular aggregates.

Synthesis and Structural Characterization of a New Hydrogen-bonded Polyrotaxane of [Co(H_2O)_6]_(2+) with 1,1′-(Propane-1,3-diyl)dipyridinium-4-carboxylate

A new double betaine 1,1′-（propane-1,3-diyl）dipyridinium-4-carboxylate L has been synthesized. Reaction of 1, 1′-（propane-1,3-diyl）dipyridinium-4-carboxylate tetrahydrate 1 with Co（ClO4）2-6H2O leads to the formation of a new Co（Ⅱ） coordination compound, namely [Co（H2O）6]-2H2O-2L-2ClO4 2. The crystal structures of 1 and 2 have been determined by single-crystal X-ray diffraction method. Crystal data for 1. monoclinic, space group C2/c, a = 18.945（4）, b = 7.700（2）, c = l 1.888（2）A,β = 101.67（3）°, V = 1698.3（6） A^3, Z = 4, F（000） = 760.0, Dc = 1.402 g/cm^3, the final R = 0.0607 and wR = 0.1607 for 950 observed reflections （1 〉 2σ（I））; and those for 2： monoclinic, space group P21/c, a = 17.982（1）, b = 15.879 （1）, c = 7.0716（5）/A,β= 100.675（1）°, V= 1984.3（3） ,A^3 Z= 4, F（000） = 1010.0, Dc = 1.631 g/cm^3, the final R = 0.0316 and wR = 0.0896 for 3784 observed reflections （1 〉20（I））. Crystal structure analysis indicates that in 1, molecules of L in a ＂V-shaped＂ conformation are linked to chains sustained by O-H…O hydrogen bonds between carboxylate groups and solvent water molecules. The chains are joined by O-H…O and C-H…O hydrogen bonds to further expand into a three-dimensional structure. For 2, molecules of L in a ＂Z-shaped＂ conformation are linked by hydrogen bonds between carboxylate groups and aqua ligands to form a chain of loops running down the b axis. The （2D→2D） polythreading in compound 2 represents the mode of parallel interpenetration of 2D sheets, having polyrotaxane character.

Theoretical Calculations on Amphoteric Adsorptions of the Hydrogenated C(100)-2×1 Surface

In this work we study the adsorptions of some small molecules or group on the hydrogenated C（100）-2×1 surface using density functional theory method. The calculated results show that the ionization potential （IP） of the hydrogenated C（100）-2×1 surfaces after adsorption has amphoteric characteristics. From the weak basic NH3 molecule with small IP and negative electron affinity （EA）, through the neutral H2O molecule, to the weak acid HF molecule and the OH group with large EA and IP, the IP values of the adsorbed diamond surfaces vary from decrease, through invariability, to slight increase for HF and obvious increase for OH. In all adsorption species, only the OH group makes the hydrogenated C（100）-2×1 surface change to the metal from the semiconductor with a wide-band gap, while the others only introduce impurity states into the electronic structures of the hydrogenated C（100）-2×1 surfaces.