Synthesis and characterization on semi-aromatic polyamide containing benzoxazole unit

In order to obtain a novel polyamide having excellent heat-resistant properties which could be anticipated as a thermal modifier for aliphatic polyamide,a series of new semi-aromatic polyamides (BO6,BO8,BO10) containing benzoxazole unit were synthesized based on 5-amino-2-(p-aminophenyl) benzoxazole (ABO) and aliphatic acids (adipic,suberic and sebacic acid) by means of Yamazaki phosphorylation method.The effect of reaction temperature on the inherent viscosity of the polymers was studied,and the structures of products were characterized by FTIR,1 H-NMR,and the heat resistance of the polymers was studied by DSC and TG.The results showed that the reaction temperature gives the polymers the highest viscosity at around 90 ℃,130 ℃ and 130 ℃ for BO6,BO8 and BO10,respectively.The heat resistance of the new semi-aromatic polyamides is much higher than that of the common aliphatic polyamides.In addition,the products show good solvent resistance and crystallization properties.

Semi-synthesis and Crystal Structure of Sophoridine N-oxide

Sophoridine N-oxide was synthesized and characterized by 1H-NMR,EI-MS,IR and elemental analysis,together with X-ray single-crystal diffraction analysis,and its crystal structure was reported for the first time.The crystal belongs to the orthorhombic system,space group P212121 with a = 8.321（2）,b = 15.650（3）,c = 24.352（5） ,V = 3171.1（11） 3,Z = 8,Dc = 1.258 g/cm3,λ（CuKα） = 1.54178,F（000） = 1440,the final R = 0.0351 and wR = 0.0970.The crystal structure shows Sophoridine N-oxide crystallizes with two host molecules of similar conformation and four water solvent molecules in the asymmetric unit.In the crystal structure,intermolecular O-H…O hydrogen bonds link the constituent molecules into a 2D layer structure,which further extends to a 3D supramolecular architecture via Van der Waals interactions and intermolecular O-H…O hydrogen bonds.

Synthesis,Crystal Structure and Fluorescent Properties of 1-(4-(Dimethylamino)benzylidene)-4-(naphthalen-1-yl) Thiosemicarbazide

The title compound, 1-4-（dimethylamino）benzylidene）-4-（naphthalene-1-yl） thiosemicarbazide （DMABNTS, C20H20N4S, Mr = 348.47）, was synthesized and characterized by elemental analysis, 1R, ^1H NMR and MS. The crystal structure of DMABNTS with 1,4-dioxane （Diox, C4H8O2） solvent molecules （DMABNTS·2Diox, C28H36N4O4S, Mr = 524.67） was determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic system, space group P21/c with a = 14.418（4）, b = 7.1702（19）, c = 28.350（7）°A,β= 101.154（6）°, V= 2875.4（13） °A^3, Z= 4, Dc= 1.212 g/cm^3, F（000） = 1120 and μ= 0.151 mm^-1. A total of 6458 reflections were collected, of which 4671 were unique. The structure was solved by direct methods and refined to the final R = 0.0732 and wR = 0.2127 for 3921 observed reflections （I〉 2σ（I））. There exist intermolecular hydrogen bonds （N（2）-H（2B）…S（1A）and N（1）-H（1A）…O（4B）） in the structure. The study of fluorescent properties ＇shows that DMABNTS emits bright solid-state fluorescence in the visible region and exhibits blue photoluminescence.

Regioselective protection of 10-deacetylbaccatin Ⅲ and semi-synthesis of paclitaxel

Semi-synthesis of paclitaxel was achieved in four steps from 10-deacetylbaccatin HI （10-DAB HI）. The key steps are the regioselective protection at the hydroxyl group at C-7 of 10-DAB HI, using 1,1′-thiocarbonyldiimidazole as a selective reagent, and the deprotection of the protected paclitaxel with a mixture of p-toluenesulfonic acid and 0.1 mol/L aqueous hydrochloride.

A highly stable and active mesoporous ruthenium catalyst for ammonia synthesis prepared by a RuCl_3/SiO_2-templated approach

Molecular nitrogen is relatively inert and the activation of its triple bond is full of challenges and of significance.Hence,searching for an efficiently heterogeneous catalyst with high stability and dispersion is one of the important targets of chemical technology.Here,we report a Ba‐K/Ru‐MC catalyst with Ru particle size of 1.5–2.5 nm semi‐embedded in a mesoporous C matrix and with dual promoters of Ba and K that exhibits a higher activity than the supported Ba‐Ru‐K/MC catalyst,although both have similar metal particle sizes for ammonia synthesis.Further,the Ba‐K/Ru‐MC catalyst is more active than commercial fused Fe catalysts and supported Ru catalysts.Characterization techniques such as high‐resolution transmission electron microscopy,N2 physisorption,CO chemisorption,and temperature‐programmed reduction suggest that the Ru nanoparticles have strong interactions with the C matrix in Ba‐K/Ru‐MC,which may facilitate electron transport better than supported nanoparticles.

Methane Oxidation to Synthesis Gas Using Lattice Oxygen of La_(1-x)Sr_xMO_(3-λ)(M =Fe,Mn) Perovskite Oxides Instead of Molecular Oxygen

In this paper, the partial oxidation of methane to synthesis gas using lattice oxygen of La1- SrxMO3-λ (M=Fe, x Mn) perovskite oxides instead of molecular oxygen was investigated. The redox circulation between 11% O2/Ar flow and 11% CH4/He flow at 900℃ shows that methane can be oxidized to CO and H2 with a selectivity of over 90.7% using the lattice oxygen of La1- SrxFeO3-λ (x≤0.2) perovskite oxides in an appropriate reaction condition, while the lost lattice x oxygen can be supplemented by air re-oxidation. It is viable for the lattice oxygen of La1- SrxFeO3-λ (x≤0.2) perovskite x oxides instead of molecular oxygen to react with methane to synthesis gas in the redox mode.

MiR-214-3p promotes proliferation and inhibits estradiol synthesis in porcine granulosa cells

Background: Granulosa cells(GCs) proliferation and estradiol synthesis significantly affect follicular development.The miR-214-3p expression in the ovarian tissues of high-yielding sows is higher than that in low-yielding sows,indicating that miR-214-3p may be involved in sow fertility. However, the functions and mechanisms of miR-214-3p on GCs are unclear. This study focuses on miR-214-3p in terms of the effects on GCs proliferation and estradiol synthesis.Results: Our findings revealed that miR-214-3p promotes proliferation and inhibits estradiol synthesis in porcine GCs. MiR-214-3p can increase the percentage of S-phase cells, the number of EdU labeled positive cells, and cell viability. However, E2 concentration was reduced after miR-214-3p agomir treatment. We also found that miR-214-3p up-regulates the expression of cell cycle genes including cell cycle protein B(Cyclin B), cell cycle protein D(Cyclin D), cell cycle protein E(Cyclin E), and cyclin-dependent kinase 4(CDK4) at the transcription and translation levels, but down-regulates the mRNA and protein levels of cytochrome P450 family 11 subfamily A member 1(CYP11A1), cytochrome P450 family 19 subfamily A member 1(CYP19A1), and steroidogenic acute regulatory protein(StAR)(i.e., the key enzymes in estradiol synthesis). On-line prediction, bioinformatics analysis, a luciferase reporter assay, RT-qPCR, and Western blot results showed that the target genes of miR-214-3p in proliferation and estradiol synthesis are Mfn2 and NR5A1, respectively.Conclusions: Our findings suggest that miR-214-3 p plays an important role in the functional regulation of porcine GCs and therefore may be a target gene for regulating follicular development.

Synthesis and Structure of 2-Isobutyl-6-(2',4'-dichlorophenyl)imidazo[2,1-b]-1,3,4-thiadiazole

The crystal structure of the title compound, 2-isobutyl-6-(2?4?dichlorophenyl)- imidazo[2,1-b]-1,3,4-thiadiazole (C14H13Cl2N3S, Mr = 326.23), has been synthesized by the treatment of 2-amino-5-isobutyl-1,3,4-thiadiazole with a-chloroaceto-2,4-dichlorophenone and determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/n with a = 12.483(7), b = 8.420(4), c = 14.998(8) ? b = 105.770(10)? V = 1517.0(14) 3, Z = 4, Dc = 1.428 g/cm3, S = 0.902, m(MoKa) = 0.558 mm-1, F (000) = 672, R = 0.0579 and wR = 0.1186. The X-ray analytic results showed that all ring atoms in the imidazothiadiazole moiety are almost coplanar. The dihedral angel between the phenyl group and hetero-cycle is 16.8(0.2)?

mi R-192-5p regulates lipid synthesis in non-alcoholic fatty liver disease through SCD-1

AIM To evaluate the levels of mi R-192-5 p in non-alcoholic fatty liver disease(NAFLD) models and demonstrate the role of mi R-192-5 p in lipid accumulation. METHODS Thirty Sprague Dawley rats were randomly divided into three groups, which were given a standard diet, a high-fat diet(HFD), and an HFD with injection of liraglutide. At the end of 16 weeks, hepatic mi R-192-5 p and stearoyl-Co A desaturase 1(SCD-1) levels were measured. Mi R-192-5 p mimic and inhibitor and SCD-1 si RNA were transfected into Huh7 cells exposed to palmitic acid(PA). Lipid accumulation was evaluated by oil red O staining and triglyceride assays. Direct interaction was validated by dual-luciferase reporter gene assays.RESULTS The HFD rats showed a 0.46-fold decrease and a 3.5-fold increase in hepatic mi R-192-5 p and SCD-1 protein levels compared with controls, respectively, which could be reversed after disease remission by liraglutide injection(P < 0.01). The Huh7 cells exposed to PA also showed down-regulation and up-regulation of mi R-192-5 p and SCD-1 protein levels, respectively(P < 0.01). Transfection with mi R-192-5 p mimic and inhibitor in Huh7 cells induced dramatic repression and promotion of SCD-1 protein levels, respectively(P < 0.01). Luciferase activity was suppressed and enhanced by mi R-192-5 p mimic and inhibitor, respectively, in wild-type SCD-1(P < 0.01) but not in mutant SCD-1. Mi R-192-5 p overexpression reduced lipid accumulation significantly in PA-treated Huh7 cells, and SCD-1 si RNA transfection abrogated the lipid deposition aggravated by mi R-192-5 p inhibitor(P < 0.01).CONCLUSION This study demonstrates that mi R-192-5 p has a negative regulatory role in lipid synthesis, which is mediated through its direct regulation of SCD-1.

Synthesis, Crystal Structure and Antitumor Activity of 2-(3-Methyl-5-(methylthio)-4H-1,2,4-triazol-4-yl)isoindoline-1,3-dione

The title compound 2-（3-methyl-5-（methylthio）-4H-1,2,4-triazol-4-yl）isoindoline- 1,3-dione （C12H10NaO2S, Mr= 274.30） has been synthesized by a three-step procedure including the cyclization, hydrazinolysis and substitution reactions, and its crystal structure was determined by X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P2/c with a = 12.264（3）, b = 14.646（3）, c = 14.349（4） A,β = 91.69（3）°,μ = 0.255 mm1, Mr = 274.30, V = 2576.2（10） A3, Z =8, Dc = 1.414 g/cm3, F（000） = 1136, R = 0.0487 and wR = 0.1329 for 4048 observed reflections with I 〉 2σ（I）. In addition, the preliminary bioassay suggested that the title compound 6 exhibits relatively good antitumor activity against HT-29 and MCF-7.

Synthesis and Structural Characterization of 2,3-Bis(hydroxymethyl)-2,3-dinitro-1,4-butanediol

2,3-Bis（hydroxymethyl）-2,3-dinitro-1,4-butanediol（C6H12N2O8） was synthesized by condensation,cyclization,oxidative dimerization and deketalization of nitromethane with a total yield of 42.4%.The structure of the title compound was characterized by 1H NMR,13C NMR,FT-IR,elementary analysis,and X-ray single-crystal diffraction analysis,which reveals that the title compound crystallizes in triclinic,space group P with a = 0.6324（2）,b = 0.6454（3）,c = 0.7062（3） nm,α= 111.550（4）,β= 95.505（4）,γ= 113.395（4）°,V = 0.23595（16） nm3,Z = 1,Mr = 240.18,Dc = 1.690 g·cm-3,μ = 0.159 mm-1,F（000） = 126,R = 0.0304 and wR = 0.0907.

Asymmetric Synthesis of (-)-1-Trimethylsilyl-ethanol with Immobilized Saccharomyces Cerevisiae Cells in Water/Organic Solvent Diphasic System

Asymmetric synthesis of (-)-1-trimethylsilyl-ethanol with immobilized Saccharomyces cerevisiae cells in water/organic solvent biphasic system was studied. The effects of shake speed, hydrophobicity of organic solvent, volume ratio of water phase to organic phase, pH value of aqueous phase and reaction temperature on the initial reaction rate, maximum yield and enantiomeric excess (ee) of the product were systematically explored. All the above-mentioned factors had significant influence on the reaction. n-Hexane was found to be the best organic solvent for the reaction. The optimum shake speed, volume ratio of water phase to organic phase, pH value and reaction temperature were 150 r.min-1, 1/2, 8 and 30 ℃ respectively, under which the maximum yield and enantiomeric excess of the product were as high as 96.8% and 95.7%, which are 15% and 16% higher than those of the corresponding reaction performed in aqueous phase. To our best knowledge, this is the most satisfactory result obtained.

Synthesis, Crystal Structure and Antitumor Activity of (E)-4-tert-Butyl-N-(2,4-dichlorobenzylidene)-5-(1,2,4-triazol-1-yl)-thiazol-2-amine

The title compound （E）-4-tert-butyl-N-（2,4-dichlorobenzylidene）-5-（1,2,4-triazol-1-yl）-thiazol-2-amine was synthesized by the reaction of 4-tert-butyl-5-（1,2,4-triazol-1-yl）-thiazol-2-amine with 2,4-dichlorobenzaldehyde, and its crystal structure was determined by singlecrystal X-ray diffraction. The crystal belongs to the triclinic system, space group P1 with a = 7.9748（4）, b = 10.1803（5）, c = 11.4603（6）, α = 102.882（1）, β = 100.253（1）, γ = 104.457（1）°, V = 850.95（7）3, Z = 2, F（000） = 392, C16H15Cl2N5S, Mr = 380.29, Dc = 1.484 g/cm3, S = 1.095, μ = 0.512 mm-1, the final R = 0.0301 and wR = 0.0965 for 3334 observed reflections （I 〉 2σ（I））. The preliminary antitumor activity shows that for the title compound the IC50 of Hela is 0.175 μmol/mL and that of Bel7402 is 0.156 μmol/mL.

Synthesis, Crystal Structure and Fungicidal Activity of N-(4-tert-buty)-5-(1,2,4-triazol-1-yl)thiazol-2-yl)propionamide

The title compound has been synthesized by the reaction of 4-tert-butyl-5-（1,2,4- triazol-1-yl）-2-aminothiazole with propionic anhydride, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to the orthorhombic system, space group Pbca with α = 18.441（2）, b = 8.3284（9）, c = 19.257（2） A, Z = 8, V = 2957.5（5） A3, Mr = 279.37, Dc = 1.255 mg/m3, S = 1.033, μ =0.219 mm^-1, F（000） = 1184, the final R = 0.0349 and wR = 0.0876 for 2629 observed reflections （I 〉 2σ（I））. X-ray crystal structure presents the intermolecular N–H···N hydrogen bond, which plays an important role in stabilizing the crystal structure. The preliminary bioassay indicates that the title compound exhibits potent fungicidal activity against R. Solani （25 mg/L） with inhibition rate of 80.0%.

Studies on Condensed Heterocyclic Compounds(Ⅲ)——Synthesis and Antibacterial Activity of 3-(4-Pyridyl)-6-Alkyl/Aromatic Heterocyclyl-s-Triazolo[3,4-b]-1, 3,4-Thiadiazoles and 1,4-Bis [6-(4-Pyridyl)-s-Triazolo [3,4-b]-1, 3,4-Thiadiazol-3-yl]-n-Butane

In recent years, fused heterocycles have been reported to possess important properties in synthesis and pharmacology. Especially, s-triazolo, 3,4-thiadiazole derivatives have been attracting much attention for chemists and pharmacologists because they show broad spectra of biological activities, such as antifungal, antibacterial, hy-

Synthesis and characterization of SrCe_(0.95)Y_(0.05)O_(3-δ) nano powders by low temperature combustion

Nanosized SrCe0.95Y0.05O3-δ powders with homogeneous composition were synthesized by the low temperature combustion process based on the Pechini method. A polymeric precursor sol was formed by using citric acid and ethylene glycol as the chelating agents of metal ions. The perovskite-type SrCe0.95Y0.05O3-δpowders with uniform shape and smaller than 25 nm in size were obtained through the combustion of the polymeric precursor sol at the existence of nitric acid and ammonium hydroxide. It was found that modulating the quantifies of nitric acid and ammonium hydroxide could control the particle size, and the quantities of residue carbonate ions were also affected by the quantifies of citric acid and ethylene glycol.

The Combustion Synthesis Process of Al-Ti-C System in an Elevated-temperature Al-melt

One of the main disadvantages of combustion synthesis of ceramic/metal composite materials is the relatively high level of porosity present in the products. To synthesize TiC/Al composites with a dense structure, this paper proposes a novel application of an elevated-temperature Al-melt to directly ignite and simultaneously infiltrate Al-Ti-C preform dipped in the melt. The emphasis was placed on the combustion synthesis process and mi-crostructural evolution of the preform in the melt, by a liquid quenching test combined with the measurement of the temperature history of the dipped preform. The results show that the combustion synthesis process of the preform in the elevated-temperature melt involves a series of reactions, and that higher temperature of the melt is favourable for the formation of TiC. The synthesized TiC/Al composites exhibit a dense structure, which is attributed to the infiltration of the melt into the preform.

Synthesis and Crystal Structure of 5,7-Dimethoxy-2-phenylquinolin-4-yl Phenyloxy (N-L-Alanine ethyl ester) Phosphoramidate

5,7-Dimethoxy-2-phenylquinolin-4-yl phenyloxy （N-L-alanine ethyl ester） phosphoramidate （C28H29N2O7P, Mr = 536.17） has been synthesized by a facial phosphorylated reaction, and its structure was determined by IR, NMR, HR MS and X-ray single-crystal diffraction. The crystal belongs to triclinic, space group P1^-, with a = 11.375（2）, b = 11.591（2）, c = 11.638（2） A^°, α= 109.46（3）, β= 104.58（3）, γ= 100.48（3）°, V = 1339.6（5）A^°^3, Z = 2, Dc = 1.330 g/cm^3,μ = 0.152 mm^-1, F（000） = 564, the final R = 0.0654 and wR = 0.1546. In the crystal structure, the title compound is constructed by a centrosymmetric dimmer unit composed of a pair of π-π stacking diastereoisomers. The compound has a noteworthy feature in the framework, and such units are linked by two equal intermolecular P=O…H-N hydrogen bonds.

Synthesis and Crystal Structure of Trans-4-[(5-(2,4-Dichlorophenoxy)-3-methyl-1-phenyl-1H-pyrazol-4-yl)methyleneamino]-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one

The title compound trans-4-[（5-（2,4-dichlorophenoxy）-3-methyl- 1-phenyl-1H-pyrazol-4-yl）methyleneamino]- 1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one 3 （C28H23Cl2N5O2, Mr = 532.41） has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group P1- with a = 8.9438（4）, b = 11.6065（5）, c = 14.2215（6）A, α = 112.566（1）, β = 92.324（2）, γ = 102.91（1）°, V= 1315.65（10） A^3, Z = 2, Dc = 1.344 g/cm^3,μ（MoKa） = 0.282 mm^-1, λ = 0.71073 A, F（000） = 552, the final R = 0.0587 and wR = 0.1578 for 5071 observed reflections （I 〉 2σ（I））. X-ray analysis reveals that the product is a thermodynamically stable trans isomer. Intra- and intermolecular C（ 12）-H（12）…O（1） and C（28）-H（28）...O（1）# 1 hydrogen bonds were observed in the title compound.

Synthesis,Crystal Structure and Antitumor Activity of N-(4-tert-butyl-5-(4-chlorobenzyl)thiazol-2-yl)-2,6-difluorobenzamide

The title compound was synthesized by the reaction of 4-tert-butyl-5-（4-chlorobenzyl）-2-aminothiazole with 2,6-difluorobenzoic acid. The crystal structure of the title compound, C21H19ClF2N2OS, was determined by single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group Pbca with a = 12.6479（13）, b = 13.1204（13）, c = 14.1341（15）, Z = 4, V = 2011.5（4）3, Mr = 420.89, Dc = 1.390 g/cm3, S = 1.023, μ = 0.326 mm-1, F（000） = 872, the final R = 0.0365 and wR = 0.0880 for 6101 observed reflections（I 〉 2σ（I））, and R = 0.0507, wR = 0.0978 for 7779 independent reflections. X-ray crystal structure displays that the hydrogen bonding interactions observed link the molecules to form a dimeric unit. The preliminary biological test of the title compound shows good antitumor activity, with IC50 of 0.046 μmol/mL against the Hela cell line.