Effects of Stephania hainanensis alkaloids on MSU-induced acute gouty arthritis in mice.

BACKGROUND: Gout is initiated by the precipitation of monosodium urate (MSU) crystals within the joints and soft tissues, and it can eventually cause acute or chronic arthritis. MSU crystals trigger, amplify, and maintain a strong inflammatory response through promoting proinflammatory activity. In this study, the therapeutic effects of Stephania hainanensis (S. hainanensis) total alkaloid (SHA) were tested and evaluated on MSU-induced acute gouty arthritis in a mouse model. METHODS: After oral administration of SHA (10 or 20 mg/kg) or the antigout medicine colchicine (0.5 mg/kg) once daily for 3 consecutive days, MSU crystals suspended in saline (2.5 mg/50 µl) were intradermally injected into the right paw of the mice. Then, SHA and colchicine were administered for another 2 days. During this period, swelling of the ankle and clinical scores were measured at 12, 24, and 48 h postinjection. After the mice were euthanized, inflammatory cytokine expression and paw tissue inflammation-related gene and protein expression, and a histopathological analysis was performed. RESULTS: SHA had obvious therapeutic effects on MSU-induced acute gouty arthritis in mice. SHA alleviated ankle swelling and inhibited the production of cytokines, such as IL-1ß and TNF-α. In addition, NLRP3, Caspase-1 and IL-1ß, which are activated by MSU were also suppressed by SHA. The histological evaluation showed that SHA relieved the infiltration of inflammation around the ankle. CONCLUSIONS: These results suggest that SHA is capable of anti-inflammatory activities and may be useful for treating gouty arthritis.

Boosting Ethane/Ethylene Separation within Isoreticular Ultramicroporous Metal-Organic Frameworks.

The separation of ethane from its analogous ethylene is of great importance in the petrochemical industry, but very challenging and energy intensive. Adsorptive separation using C2H6-selective porous materials can directly produce high-purity C2H4 in a single operation but suffers from poor selectivity. Here, we report an approach to boost the separation of C2H6 over C2H4, involving the control of pore structures in two isoreticular ultramicroporous metal-organic framework (MOF) materials with weakly polar pore surface for strengthened binding affinity toward C2H6 over C2H4. Under ambient conditions, the prototypical compound shows a very small uptake difference and selectivity for C2H6/C2H4, whereas its smaller-pore isoreticular analogue exhibits a quite large uptake ratio of 237% (60.0/25.3 cm3 cm-3), remarkably increasing the C2H6/C2H4 selectivity. Neutron powder diffraction studies clearly reveal that the latter material shows self-adaptive sorption behavior for C2H6, which enables it to continuously maintain close van der Waals contacts with C2H6 molecules in its optimized pore structure, thus preferentially binds C2H6 over C2H4. Gas sorption isotherms, crystallographic analyses, molecular modeling, selectivity calculation, and breakthrough experiment comprehensively demonstrate this unique MOF material as an efficient C2H6-selective adsorbent for C2H4 purification.

Multistimuli-Responsive Luminescence of Naphthalazine Based on Aggregation-Induced Emission.

Stimuli-responsive luminescent materials, which are dependent on changes in physical molecular packing modes, have attracted more and more interest over the past ten years. In this study, 2,2-dihydroxy-1,1-naphthalazine was synthesized and shown to exhibit different fluorescence emission in solution and solid states with characteristic aggregation-induced emission (AIE) properties. A remarkable change in the fluorescence of 2,2-dihydroxy-1,1-naphthalazine occurred upon mechanical grinding, heating, or exposure to solvents. According to the characterization by solid-state fluorescence spectroscopy, X-ray crystallography, differential scanning calorimetry, and X-ray powder diffraction, the fluorescence change could be attributed to transitions between two structurally different polymorphs. These significant properties could also give 2,2-dihydroxy-1,1-naphthalazine more potential applications as a multifunctional material.

Turn-on phosphorescent chemodosimeter for Hg2+ based on a cyclometalated Ir(III) complex and its application in time-resolved luminescence assays and live cell imaging.

A novel "turn-on" phosphorescent chemodosimeter based on a cyclometalated Ir(III) complex has been designed and synthesized, which displays high selectivity and sensitivity toward Hg(2+) in aqueous media with a broad pH range of 4-10. Furthermore, by time-resolved photoluminescence techniques, some interferences from the short-lived background fluorescence can be eliminated effectively and the signal-to-noise ratio of the emission detection can be improved distinctly by using the chemodosimeter. Finally, the chemodosimeter can be used to monitor Hg(2+) effectively in living cells by confocal luminescence imaging.

An 1,3,4-oxadiazole-based OFF-ON fluorescent chemosensor for Zn2+ in aqueous solution and imaging application in living cells.

A new 1,3,4-oxadiazole-based fluorescence chemosensor 1, N-(2-ethoxy-2-oxoethyl)-N-(5-(2-hydroxy-3,5-di-tert-butylphenyl)-[1,3,4]oxadiazol-2-yl)glycine ethyl ester, has been designed and synthesized. Its fluorescence properties and selectivity for various metal ions were investigated in detail. A prominent fluorescence enhancement only for Zn(2+) was found in aqueous acetonitrile solution and the response mechanism of 1 was analyzed by time-resolved fluorescence decay and DFT calculations. Furthermore, the fluorescence imaging of Zn(2+) in living cells was successfully applied.

Olive-shaped chiral supramolecules: simultaneous self-assembly of heptameric lanthanum clusters and carbon dioxide fixation.

Cluster's last stand: Six chiral reduced Schiff base ligands containing amino acids and seven La(III) ions self-assemble to form a novel heptameric lanthanum supramolecule with the aid of the CO(3)(2-) ion (see picture). The cluster exists as a single chiral triple helix. The CO(3)(2-) ion, which is derived from atmospheric CO(2) , adopts a rare mu(3)-tridentate bridging mode that links three La(III) ions, thus allowing the cluster to efficiently fix CO(2).

4-(Hydroxy-meth-yl)phenol.

In the mol-ecule of the title compound, C(7)H(8)O(2), the phenol O and hydroxy-methyl C atoms lie in the ring plane [deviations of -0.015 (3) and and 0.013 (3) Å, respectively]. In the crystal structure, inter-molecular O-H⋯O hydrogen bonds link mol-ecules into a network. A weak C-H⋯π inter-action is also found.

Tuning the self-assembly and luminescence properties of lanthanide coordination polymers by ligand design.

Two new structure-related tripodal ligands featuring salicylamide pendant arms, 1,3,5-tris{[(2'-furfurylaminoformyl)phenoxyl]methyl}-2,4,6-trimethylbenzene (L(I)) and 1,1,1-tris{[(2'-furfurylaminoformyl)phenoxyl]methyl}ethane (L(II)) have been designed and synthesized with the ultimate aim of self-assembling lanthanide polymers with interesting luminescent properties. Among two series of Ln(III) nitrate complexes (Ln = Pr, Nd, Sm, Eu, Gd, Tb or Dy) which have been characterized by elemental analyses, XRD, TGA and IR spectra, three new coordination polymers have been determined by X-ray diffraction analysis. The coordination polymer type {[Ln(NO(3))(3)(L(I))].nH(2)O}(n) possesses an unusual ladderlike double chain which can be further connected through pi-pi stacking interactions constructing a three-dimensional supramolecular structure. In contrast, the coordination polymer type {[Ln(NO(3))(3)(L(II))].nCH(3)OH}(n) displays a (3,3)-connected puckered two-dimensional net with 4.8(2) topological notation. The photophysical properties of the Sm, Eu, Tb and Dy complexes at room temperature are investigated. The present work substantiates the claim that the supramolecular structure as well as the luminescent properties of the coordination polymer can be tuned by varying either the backbone group or the terminal group of the organic ligand.

Design of a semirigid molecule as a selective fluorescent chemosensor for recognition of Cd(II).

A new 8-hydroxyquinoline-based chemosensor possessing a semirigid structure was designed, and its fluorescent sensing behavior toward metalions was investigated. A prominent fluorescence enhancement only for Cd(2+) was found in aqueous methanol solution. The results clearly suggest that the specific semirigid structure could selectively accommodate Cd(2+) according to ionic radius, which would effectively suppress the intramolecular radiationless transitions from the n pi* state to enhance the fluorescence response.

Synthesis of a new C(2)-symmetric chiral catalyst and its application in the catalytic asymmetric borane reduction of prochiral ketones.

A new C(2)-symmetric chiral catalyst 3,5-bis[(2S)-(hydroxy-diphenylmethyl)- pyrrolidin-1-ylmethyl]-1,3,4-oxadiazole was successfully synthesized by the reaction of 2,5-dichloromethyl-1,3,4-oxadiazole with (S)-alpha,alpha-diphenyl-2-pyrrolidinemethanol, and applied to the catalytic asymmetric reduction of prochiral ketones with borane. When the catalyst loading was 1 mol %, enantiomeric excesses of up to 86.8% and 94.5% were observed in reduction of aromatic and alpha-halo ketones, respectively.

[Spectral diagnosis of plasma jet at atmospheric pressure].

A new approach to surface modification of materials using dielectric barrier discharge (DBD) plasma jet at atmospheric pressure is presented in the present paper. The emission spectral lines of argon plasma jet at atmospheric pressure were recorded by the grating spectrograph HR2000 and computer software. The argon plasma emission spectra, ranging from 300nm to 1000 nm, were measured at different applied voltage. Compared to air plasma emission spectra under the same circumstance, it is shown that all of the spectral lines are attributed to neutral argon atoms. The spectral lines 763.51 and 772.42 nm were chosen to estimate the electron excitation temperature. The purpose of the study is to research the relationship between the applied voltage and temperature to control the process of materials' surface modification promptly. The results show that electron excitation temperature is in the range of 0.1-0.5 eV and increases with increasing applied voltage. In the process of surface modification under the plasma jet, the infrared radiation thermometer was used to measure the material surface temperature under the plasma jet. The results show that the material surface temperature is in the range of 50-100 degrees C and it also increases with increasing applied voltage. Because the material surface was under the plasma jet and its temperature was decided by the plasma, and the material surface temperature increased with increasing the macro-temperature of plasma jet, the relationship between the surface temperature and applied voltage indicates the relationship between the macro-temperature of the plasma jet and the applied voltage approximately. The experimental results indicate that DBD plasma jet at atmospheric pressure is a new approach to improving the quality of materials' surface modification, and spectral diagnosis has proved to be a kind of workable method by choosing suitable applied voltage.

[N'-(1,3-Dioxoindan-2-yl-idene)-2-oxido-benzohydrazidato-κO,N,O]tripyridine-nickel(II) pyridine solvate.

In the title compound, [Ni(C(16)H(8)N(2)O(4))(C(5)H(5)N)(3)]·C(5)H(5)N, the Ni(II) atom is six-coordinated by two O atoms and one N atom from the Schiff base ligand and by three N atoms from three pyridine mol-ecules, forming a distorted octa-hedral geometry. The Ni-O(phenolate) bond [1.9750 (16) Å] is shorter than the Ni-O(carbon-yl) bond [2.0840 (16) Å] and the Ni-N bonds (mean 2.120 Å).

{1,8-Bis[2-(2-oxidobenzyl-idene-amino)phen-oxy]-3,6-dioxaocta-ne}nitrato-praseodymium(III) trichloro-methane solvate.

In the title compound, [Pr(C(32)H(30)N(2)O(6))(NO(3))]·CHCl(3), the Pr(III) ion is ten-coordinated by eight O atoms and two N atoms from the acyclic crown-type Schiff base ligand and the bidentate nitrate group. The coordination polyhedron around Pr(III) is a distorted bicapped square anti-prism. The chloro-form solvent mol-ecule is not involved either in coordination to the Pr(III) center or in hydrogen bonding to the complex. The Pr-O(phenolate) bonds are significantly shorter than the Pr-O(ether) and Pr-O(nitrate) bonds, which suggests that the Pr-O(phenolate) bond is stronger than these other bonds. In the crystal structure, the acyclic crown-type Schiff base ligand wraps around the Pr(III) centre, forming a pseudo-ring.

Synthesis, infrared and fluorescence spectra of lanthanide complexes with a new amide-based 1,3,4-oxadiazole derivative.

A new amide-based 1,3,4-oxadiazole derivative ligand 2,5-bis[2-(N,N-diethyl-1'-oxopropylamide)phenyl]-1,3,4-oxadiazole (L) and its complexes, Ln(NO3)3L (Ln=La, Eu, Gd, Tb, Er), were synthesized. The complexes were characterized by elemental analysis, infrared spectra and conductivity. The lanthanide ions were coordinated by O atoms from CO. The fluorescence properties of Eu(NO3)3L and Tb(NO3)3L in the solid state and in different solvents were investigated. Under the excitation of UV light, these complexes exhibit characteristic fluorescence of europium and terbium ions. The solvent factors influencing the fluorescent intensity were discussed.

[Spectral diagnosis of dielectric barrier plasma discharge at atmospheric pressure and its application to surface modification of materials].

The spectral lines of air and argon plasma emission at atmospheric pressure were recorded and analyzed. Plasma parameters such as discharge current, discharge gap and electron temperature were measured. The purpose of the study is to control the process of materials' surface modification promptly. The experimental results indicate that a critical discharge gap is an important parameter to improve the quality of materials' surface modification, and spectral diagnosis has been proved to be a workable method by choosing a suitable discharge gap.