Characterization ofanovel deep-seamicrobial esterase EstC 10 and its use in the generation o f(R)-methyl 2-chloropropionate

A novel esterase EstC10 from Bacillus sp. CX01 isolated from the deep sea of the Western Pacific Ocean and the functionalities of EstC 10 was characterized. At present, the reports about the kinetic resolution ofracemic methyl 2-chloropropionate were quite rare. So we developed deep-sea microbial esterase EstC10 as a novel biocatalyst in the kinetic resolution of racemic methyl 2-chloropropionate and generate （R）-methyl 2-chloropropionate with high enantiomeric excess （〉99%） after the optimization of process parameters such as pH, temperature, organic co-solvents, surfactants, substrate concentration and reaction time. Notably, the optimal substrate concentration （80 mmol/L） of esterase EstC10 was higher than the kinetic resolution of another esterase, Estl2-7 （50 mmoFL）. The novel microbial esterase EstC10 identified from the deep sea was a promising green biocatalyst in the generation of （R）-methyl 2-chloropropionate as well of many other valuable chiral chemicals in industry.

Synthesis, Crystal Structure and DNA-Binding Property of a Mn(Ⅱ) Complex Based on 5-(Tri-fluoromethyl)pyridine-2-carboxylic Acid

A new complex Mn(Htpc)2(H2O)2(1, Htpc = 5-(trifluoromethyl)pyridine-2-carboxylic acid) has been synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. 1 belongs to triclinic system, space group P■ with a = 5.0885(10), b = 6.5574(13), c = 14.016(3) ?, β = 90.67(3)o, V = 436.34(17) ?3, Z = 1, Dc = 1.793 g·cm-3, μ = 0.855 mm-1, Mr = 471.18, F(000) = 235, the final R = 0.0454 and wR = 0.1134 for 1998 observed reflections with I > 2σ(I). The Mn(Ⅱ) ion is coordinated by two N and two O atoms from two Htpc as well as two O atoms from two coordinated water molecules, forming a 0D motif with distorted octahedral coordinate geometry. The adjacent 0D units are linked into 1D chains through hydrogen bond O(1W)–H(1 WB)···O(2), and via the O(1 W)–H(1 WA)···O(1) hydrogen bond the neighboring 1D chains are connected into a 2D supramolecular layer. Moreover, the interactions between the ligand and its complex with CT-DNA were studied by EtBr fluorescence probe, which suggested that these compounds bind to CT-DNA through an intercalation mode. The binding constants were 0.41 and 0.64 for Htpc and complex 1, respectively. It indicates that the interaction between complex 1 and CT-DNA is stronger than Htpc.

Controlled Self-assembly of Two Coordination Polymers via subtly Varying Bis(2-methyl imidazole) Ligands:from 3-Connected(6,3) Net to 4-Connected sql Net

Two coordination polymers constructed from 3,4-thiophenedicarboxylic acid and bis（2-methyl imidazole） ligands, namely, {[Cd2（tdc）2（bip）2]·7H20}n （1） and [Cd（tdc）（bib）]n （2） （Hgtdc = 3,4-thiophenedicarboxylic acid, bip = 1,3-bis-（imidazol-2-methyl）propane and bib = 1,4-bis（imidazol-2-methyl）butane）, have been synthesized and structurally characterized by single-crystal X-ray diffraction. Structural analyses reveal that 1 exhibits a two-dimensional （2D） layered network with 3-connected （6,3） topology, which is further connected into a three- dimensional （3D） supramolecular structure by intermolecular hydrogen bonds. However, 2 features a 2D network which can be rationalized as a 4-connected sql net. The results indicate the subtle difference of auxiliary bis（imidazol-2-methyl） ligands may lead to diverse architectures. Moreover, they exhibit luminescence emission in the solid state at room temperature.

Synthesis and fluorescence properties of Tb(Ⅲ) complexes with pyridine-2,6-dicarboxylic acid derivatives

Two novel ligands named 4-styrylpyridine-2,6-dicarboxylic acid (4-SPDA) and 4-(4-(2-(2, 6-dicarboxypyridin-4-yl)- vinyl)styryl)pyridine-2,6-dicarboxylic acid(DSPDA) and their complexes with Tb(Ⅲ) were synthesized and characterized by infrared spectrometry, 1H nuclear magnetic resonance, elemental analysis and gas chromatograph-mass spectrometry. The ligand synthetic route was optimized. The fluorescence properties of the complex in solid state, in different kind of solvents and in solutions with different pH values were investigated in detail. The results show that the yields of DSPDA and 4-SPDA reach over 78% by Wittig-Horner reaction and other eight pyridine-2, 6-dicarboxylic acid derivatives with different substituents on pyridine ring, and their complexes with Tb(Ⅲ) are also obtained. The fluorescence intensities of the complexes with electron-donating groups are more intense than those of the complexes with electron-withdrawing groups on pyridine ring; fluorescence intensities of the complexes are the strongest in neutral solution (pH=7), and the less the dipole moment of solvent molecule is, the stronger the fluorescence intensity is. It is found that the two ligands (4-APDA and DSPDA) are the good sensitizers for Tb(Ⅲ) ion.

Influence of surfactant concentration on counter-ion induced solubility of poly(pyridine-2,5-diyl)

Protonating the pyridine rings of poly(pyridine-2,5-diyl) with dodecybenzenesulfonic acid and camphorsulphonic acid produces polymer materials which can be dissolved in chloroform (in contrast to the unprotonated polymer, which can only be dissolved in strong acids such as formic acid) and allows mixing the protonated polymers with other chloroform soluble conju- gated polymers for use in electronic devices. The protonating behavior of poly(pyridine-2,5-diyl) with two kinds of surfactants is different in some levels. Dodecybenzenesulfonic acid has higher protonating ability than camphorsulphonic acid.

Crystal Structures of Schiff Base from 4-Aminoantipyrine and Pyridine-2-carboxaldehyde and Its Perchlorate

The Schiff base pyridine-2-carboxaldehyde-4-aminoantipyrine （CI7H16N4O 1） and its perchlorate （C17H17N4O·ClO4 2） have been prepared and characterized by elemental analysis, IR spectra and single-crystal X-ray crystallography analysis. Both 1 and 2 crystallize in the monoclinic system, space group P21/c. For 1, a = 8.6820（12）, b = 24.934（3）, c = 7.0064（10） A,, β= 97.942（3）°, V = 1502.2（4） A^3, Z = 4, Dc = 1.293 g/cm^3, F（000） = 616,μ = 0.084 mm^-1, the final R = 0.0592 and wR = 0.1244. For 2, a = 5.9302（2）, b = 20.347（7）, c = 14.663（6） A, β= 90.200（9）°, V= 1769.201） A^3, Z = 4, Dc = 1.475 g/cm^3, F（000） = 816, μ = 0.254 mm^-1, the final R = 0.0533 and wR = 0.0819. As expected, both molecular structures of 1 and 2 adopt a trans configuration about the central C=N double bond. 2 is an ionic compound with the protonation at N（1） of pyridine-2-carboxaldehyde-4- aminoantipyrine.

Theoretical Study on the Reaction Mechanism of o-Aminophenol, Acetic Acid and Phosphorus Oxytrichloride One-pot to Form 2-Methyl Benzoxazole

The reaction mechanism of o-aminophenol, acetic acid and phosphorus oxytrichloride in one-pot to form 2-methyl benzoxazole was studied by density functional theory. The geometries of the reactants, transition states, intermediates and products were optimized at the GGA/PW91/DNP level. Vibration analysis was carried out to confirm the transition state structure. Two possible reaction pathways were investigated in this study. The result indicates that the reaction Re→TS1→IM1→TSA2→IMA2→TSA3→IMA3→TSA4→IMA4→TSA5→P2 is the main pathway, the activation energy of which is the lowest. Re→TS1→IM1 is the rate-limiting step, with the activation energy being 221.54 kJ·mol^(-1) and the reaction heat being 10.06 kJ·mol^(-1). The dominant product predicted theoretically is in agreement with the experiment results.

XRD Pattern of Liquid Crystal Monomer Acrylate That Conjugated with Cholesterol and p-Hydroxyphenyl-2-Methyl Butanoic

It was successfully synthesized liquid crystal monomer acrylate that conjugated with two mesogens were cholesterol and p-hydroxyphenyl-2-methyl Butanoat which called MA （monomer cholesteryl acrylate） and monomer （S）-（＋）-4-（2-Methyl butanoat-l-butyloxy） phenyl 4-[1-（propenoyloxy） butyloxy] benzoate （MB）. Two monomers were characterized by DSC （differential scanning calorimetry）, POM （polarization optical microscopy） and XRD （X-ray diffraction）. Mesophase temperatures of MA and MB are 81.28 ~C and 54.36~C, respectively. Textures analysis by POM shows that MA was oily streak and MB was schlieren. XRD pattern shows the strongest three peaks of MA at room temperature which are （20, deg）： 2.7153, 5.2992 and 18.8500. The Strongest three peaks of MB at room temperature are （20, deg）： 9.1726, 9.7707 and 12.5389. XRD pattern of MA and MB at mesophase and above mesophase temperature that each peaks disappear.

Theoretical Study on the Reaction Mechanism of 2-Methoxybenzaldehyde,4-Bromo-indanone,Malononitrile and Ammonium Acetate One-pot to Form 6-(2-Methoxyphenyl)-2-amino-6-bromo-5H-indeno[1,2-b]pyridine-3-carbonitrile

The reaction mechanism of 2-methoxybenzaldehyde, 4-bromo-indanone, malononitrile and ammonium acetate one-pot to form 6-（2-methoxyphenyl）-2-amino-6-bromo-5 Hindeno[1,2-b]pyridine-3-carbonitrile was studied by density functional theory. The geometries of the reactants, transition states, intermediates and products were optimized at the PW91/DNP level. Vibration analysis was carried out to confirm the transition state structure. Reaction pathways were investigated in this study. The result indicates that the reaction Re→ TSB1→IMB1→ TSB2→ IMB2→TSB3→IMB3→TSB4→IMB4→TSB5→IMB5→TSB6→IMB6→TSB7→IMB7→ TSB8→IMB8→TSB9→IMB9→P2 is the main pathway, the activation energy of which is the lowest. The dominant product predicted theoretically is in agreement with the experiment results.

Green Chemistry Approach to Fast and Highly Efficient One-Pot Synthesis of Bis-Isoxazolyl-1,2,5,6-Tetrahydro Pyridine-3-Carboxylates

The synthesis of the bis-isoxazolyl-1,2,5,6-tetrahydro pyridine-3-carboxylates is achieved in high yield without the production of toxic waste products by using room temperature ionic liquid (RTILs) triethyl ammonium acetate (TEAA). The RTIL TEAA played the dual role of efficient green solvent as well as recyclable catalyst.

THE FIRST BINUCLEAR MOLYBDENUM AND TUNGSTEN COMPLEXES WITH DOUBLY-BRIDGING PYRIDINE-2-THIOLATO LIGANDS.X-RAY CRYSTAL STRUCTURE OF THE COMPLEX[Mo_2(CO)_4(μ-pyS)_2(PPh_3)_2].2C_7H_8

The title complex was obtained by reactions of [Mo(CO)_3(MeCN)_3] with [CuBr(pySH)(PPh_3)_2]or directly with pySH and PPh_3. The latter method can be used to synthesize the corresponding tungsten complex [W_2(CO)_4(μ-pyS)_2(PPh_3)_2].The molecular structure of the title compound was determined by X-ray diffraction method.

Interaction of N-(2-Methyl Thio Phenyl)-2-Hydroxy-1-Naphthaldimine with Tin Dioxide Nanoparticles: A Spectroscopic Approach

The interaction of N-(2-methyl thiophenyl)-2-hydroxy-1-naphthaldimine (NMTHN) with tin dioxide nanoparticles (SnO2 NPs) has been investigated by spectroscopic tools such as absorption and fluorescence spectroscopy. Absorption spectroscopy reveals the formation of ground state complex. Fluorescence spectroscopy has been used to study the signatures of fluorescence quenching. SnO2 NPs are found to quench the intrinsic fluorescence of NMTHN via static and dynamic quenching. The deviation from linearity in the Stern-Volmer plot has been observed.

Synthesis of Some New Pyridine-2-yl-Benzylidene-Imines

A series of new Schiff bases derived from 2-aminopyridenes and various aromatic aldehydes have been synthesized and thoroughly investigated by 1H and 13C NMR spectroscopy. The imines were found to exist as only a single E-isomer at ambient temperature. Interestingly, 1H- and 13C-NMR chemical shifts of the (CH=N) amino group are affected by the type of substituent group (X) on the aryl ring. Furthermore UV and IR Spectra of some of the title compounds are also reported.

Synthesis, Structure and Property of a Novel Coordination Polymer [Tb(C_7H_3NO_4)(C_6H_4NO_2)(H_2O)]

A novel terbium(III) coordination polymer [Tb(C7H3NO4)(C6H4NO2)(H2O)] was successfully synthesized hydrothermally and characterized by single-crystal X-ray diffraction. The complex is of monoclinic, space group P21/c with a = 9.2252(11), b = 14.1477(16), c = 10.5134(12) A, β = 95.770(2)°, V = 1365.2(3) A3, Z = 4, Dc = 2.248 g·cm-3, F(000) = 880, the final R = 0.0176 and w R = 0.0411 for 2149 observed reflections with I 】 2σ(I). The complex is extended into a three-dimensional network structure with 24-atom rings which are composed of Tb, C and O atoms. The complex displays green fluorescence emission in the solid state at room temperature, which corresponds to 5D4 → 7F5 transition of the Tb(III) ion.

Synthesis and Crystal Structure of (Z)-1- (3-Fluorobenzyl)-5-((3-fluorobenzylimino)(2-hydroxy-4-methoxyphenyl)methyl)pyridin-2(1H)-one

The title compound （Z）-1-（3-fluorobenzyl）-5-（（3-fluorobenzylimino）（2-hydroxy-4- methoxyphenyl）methyl）pyridin-2（1H）-one （C27H22F2N2O3,Mr = 460.47） was synthesized and crystallized. The crystal belongs to the triclinic system,space group P1 with a = 9.951（6）,b = 10.059（6）,c = 12.927（7）A,α = 109.828（7）,β = 102.304（7）,γ = 104.898（7）°,Z = 2,V = 1110.2（11）A^3,Dc =1.377 Mg/m^3,μ（MoKα） = 0.102 mm^-1,F（000） = 480,the final R = 0.0449 and Rw = 0.1250 for 4595 observed reflections （I 〉 2σ（I））. X-ray analysis reveals that both m-fluorobenzyl groups are diorientationally disordered because of the rotation of C–C single bond which was represented as F（1）,F（2） and F（1＇）,F（2＇）. The diorientational disorder was refined and gave the occupancies of 0.665（4） and 0.335（4） for F（1） and F（1＇）,0.631（3） and 0.369（3） for F（2） and F（2＇）. Hydrogen bonds existing in the cell link different components to stabilize the crystal structure. The active data proved that the title compound has good anti-HBV activity.

Synthesis and Structure of Chromium Complexes with New Tetradentate Schiff Base N202-Type Ligand

In this research two chromium（II][） and （VI） complexes of tetradentate Schiff bases have been prepared by condensing of salicylaldehyde with 4-methyl 1,2-phenylenediamine. Schiff base complexes of chromium（Ill） have been employed to design and synthesize polynuclear complexes. So they have played an important role in molecular magnetism. Synthesized complexes were characterized by elemental analysis, IR, molar conductivity and NMR. The free ligands were alsc characterized by 1H, 13C NMR spectra. The 13C NMR and IR spectra of free ligand and the complexes are compared and discussed.

Synthesis and Crystal Structure of(E)-Ethyl 2-(4-(2,4-dimethoxybenzylideneamino)-5-(3,4,5-trimethoxyphenyl)-4H-1,2,4-triazol-3-ylthio)acetate

The crystal structure of the title compound(E)-ethyl 2-(4-(2,4-dimethoxy benzylide-neamino)-5-(3,4,5-trimethoxyphenyl)-4H-1,2,4-triazol-3-ylthio)acetate(4,C_(24)H_(28)N_(4)O_(7)S,Mr=516.17)was synthesized and determined by X-ray single-crystal diffraction.The crystal belongs to the monoclinic system,space group P2_(1)/n with a=13.162(2),b=8.4506(13),c=22.602(4)Å,β=99.888(3)°,μ=0.183 mm^(-1),V=2476.5(7)Å^(3),Z=4,D_(c)=1.385 g/cm^(3),F(000)=1088,T=110(2)K,R=0.0426 and wR=0.1216 for 3859 observed reflections with I 2σ(Ⅰ).

Talachalasins A-C,Undescribed Cytochalasans with a 16β-Methyl or 2-Oxabicyclo[3.3.1]nonan-3-one unit from the Deep-Sea-Derived Fungus Talaromyces muroii sp.SCSIO 40439

Comprehensive Summary Talachalasins A-C(1-3),three new cytochalasans(CYTs),were isolated from deep-sea-derived fungus Talaromyces muroii sp.SCSIO 40439.The structures of 1-3,including absolute configurations,were determined based on HRESIMS,NMR spectroscopic data,ECD comparison,and single crystal X-ray diffraction analysis.Talachalasins A-C(1-3)represented the first examples of cytochalasans possessing a unique 16β-methyl group,distinct from>500 reported CYTs.Talachalasin C(3)was an unprecedented 20,21-seco-cytochalasans characterized by a 2-oxabicyclo[3.3.1]nonan-3-one unit.Talachalasin A(1)displayed moderate cytotoxic activity against four tumor cell lines(IC_(50)3.40-10.02μM).Talachalasin B(2)showed comparable anti-RSV and HSV-1 activities(IC5012.5μM or IC5020.0μM).

一种胶粘剂的裂解GC-MS分析

目前胶粘剂广泛应用于木材加工、建筑、轻纺工业、交通运输、电工工业、机械工业、医疗卫生、日用生活、军事工业等各个领域,已成为不可缺少的重要材料之一,因此对各种胶粘剂的分析就显得十分重要.……