雷帕霉素产生菌突变株FC904-107发酵产生7-O-ethyl-rapamycin

在雷帕霉素产生菌吸水链霉菌FC904突变株FC904-107的发酵液中发现一个雷帕霉素同系物FIM-4025,用反相硅胶柱层析等提取纯化并获得晶体。经理化性质、UV、IR、LC-MS、NMR等波谱分析,单晶X-Ray衍射确定构型,结果表明雷帕霉素同系物FIM-4025与雷帕霉素化学半合成的衍生物7-O-乙基雷帕霉素同质。

2-Ethyl-9,10-anthraquinone assisted sol–gel synthesis of Pd/γ-Al2O3 nanorods with enhanced catalytic performance in 2-ethyl-9,10-anthraquinone hydrogenation

A series of nanorod-like porous Pd/γ-Al2 O3 catalysts with controllable textural properties and enhanced catalytic performance in 2-ethyl-9,10-anthraquinone(eAQ) hydrogenation for H2 O2 preparation were successfully prepared via a facile sol-gel method using aluminum isopropoxide as aluminum precursor and eAQ as structure directing agent,sequential calcination and impregnation process with Na2 PdCl4 solution.The physicochemical properties of the catalysts obtained with different addition amounts of eAQ.were comparatively characterized by XRD,TG-DSC,BET,TEM,CO-TPR,H2-TPR and H2-O2 titration.The results show that addition of eAQ can not only effectively control the textural properties(surface area,pore volume and average pore size) of the catalysts,but also lower their reduction temperature of active metal.Importantly,the catalyst obtained with an addition amount of 4 wt% eAQ shows the highest hydrogenation efficiency of 10.28 g·L^-1,which is 37.3% higher than 7.49 g·L^-1 of the catalyst obtained without eAQ.

Scale-up of biomass conversion using 1-ethyl-3-methylimidazolium acetate as the solvent

This scale-up study demonstrated the feasibility of an ionic liquid(IL)pretreatment process at 40 kg scale,using the IL 1-ethyl-3-methylimidazolium acetate([C2C1Im][OAc])as the solvent.The pretreatment was followed by enzymatic hydrolysis through which the process efficiency for biomass conversion to monomeric sugars was determined.The results show that 43 wt%of switchgrass was dissolved in IL after 2 h of pretreatment at 160℃ with 15 wt%solid loading.A 120 h enzymatic hydrolysis of the pretreated switchgrass results in 96%glucan and 98%xylan conversion.[C2C1Im][OAc]pretreatment has been successfully scaled up to 40 kg with improved sugar titers and yields relative to bench scale(6 kg).The mass flow of the overall process was established and the major scale-up challenges of the process were identified.

Structures and Properties of Two Pillared-layer Mn(Ⅱ) MOFs with 5-Ethyl-pyridine-2,3-dicarboxylate

The reaction of Mn(OAc)2·4 H2 O, 5-ethyl-pyridine-2,3-dicarboxylic acid(H2 epda) and 4,4?-bipyridine(4,4?-bipy)/4,4?-bis(imidazolyl)biphenyl)(bibp) under hydrothermal conditions produced two new manganese(Ⅱ) MOFs [Mn(epda)(4,4?-bipy)1/2](1) and [Mn(epda)(bibp)1/2](2), which were characterized by elemental analysis, infrared spectroscopy, thermogravimetric analyses, and single-crystal X-ray diffraction. The structures of complexes 1 and 2 are similar. In 1, the adjacent Mn(Ⅱ) ions are connected by epda dianion to generate a 2 D(4,4) grid layer, and such 2 D layers are further connected via bibp ligand to form another layer, forming a 2 D pillared-layer. Topologically, the Mn atoms as the node are bridged by the edpa anions and bibp ligands to form a uninodal 5-connected network topology. The magnetic properties of 1 and 2 have also been-investigated, and the exchange interctions were –1.39 and –1.05 cm1, respectively. According to the crystal structures, compounds 1 and 2 were carried out by using hybrid DFT methods at the B3 LYP/6-31 G(d) level. The DFT-BS approach was applied to study the magnetic coupling behaviors for 1 and 2. The result reveals that the calculated exchange coupling constants J were in good agreement with the experimental data.

Superior gallstone dissolubility and safety of tert-amyl ethyl ether over methyl-tertiary butyl ether

BACKGROUND The use of methyl-tertiary butyl ether(MTBE)to dissolve gallstones has been limited due to concerns over its toxicity and the widespread recognition of the safety of laparoscopic cholecystectomy.The adverse effects of MTBE are largely attributed to its low boiling point,resulting in a tendency to evaporate.Therefore,if there is a material with a higher boiling point and similar or higher dissolubility than MTBE,it is expected to be an attractive alternative to MTBE.AIM To determine whether tert-amyl ethyl ether(TAEE),an MTBE analogue with a relatively higher boiling point(102°C),could be used as an alternative to MTBE in terms of gallstone dissolubility and toxicity.METHODS The in vitro dissolubility of MTBE and TAEE was determined by measuring the dry weights of human gallstones at predetermined time intervals after placing them in glass containers with either of the two solvents.The in vivo dissolubility was determined by comparing the weights of solvent-treated gallstones and control(dimethyl sulfoxide)-treated gallstones,after the direct infusion of each solvent into the gallbladder in both hamster models with cholesterol and pigmented gallstones.RESULTS The in vitro results demonstrated a 24 h TAEE-dissolubility of 76.7%,56.5%and 38.75%for cholesterol,mixed,and pigmented gallstones,respectively,which represented a 1.2-,1.4-,and 1.3-fold increase in dissolubility compared to that of MTBE.In the in vitro experiment,the 24 h-dissolubility of TAEE was 71.7%and 63.0%for cholesterol and pigmented gallstones,respectively,which represented a 1.4-and 1.9-fold increase in dissolubility compared to that of MTBE.In addition,the results of the cell viability assay and western blot analysis indicated that TAEE had a lower toxicity towards gallbladder epithelial cells than MTBE.CONCLUSION We demonstrated that TAEE has higher gallstone dissolubility properties and safety than those of MTBE.As such,TAEE could present an attractive alternative to MTBE if our findings regarding its efficacy and safety can be consistently reproduced in further subclinical and clinical studies.

Synthesis and Crystal Structure of Tri(4-(3-hydroxy2-ethyl-4-pyridinone-1-yl)-aniline Condensation Salicylaldehydato) Monohydratotricopper(II)Dimethylformamide Monohydrate Solvate

The title complex [Cu3L3(H2O)]DMFH2O (H2L = 4-(3-hydroxy-2-ethyl-4- pyridinone-1-yl)-aniline condensation salicylaldehyde) was obtained. The single-crystal X-ray study shows that it is a trinuclear compound [Cu3(C20H15N2O3)3(H2O)]DMFH2O. The coordi- nation sphere about each copper ion in the complex consists of two oxygen atoms from hydroxylpyridinone moiety of one ligand and one oxygen and one nitrogen atoms from salicyladehyde Schiff-base moiety of another ligand arranged in a slightly distorted square planar geometry. Among the three copper ions, one (Cu(2)) is coordinated by the other oxygen atom of water molecule on the fifth coordinate position to form a distorted square pyramid geometry. The crystal is of monoclinic, space group P21/c with a = 12.9202(5), b = 27.197(1), c = 17.0116(7) ? b = 100.588(1), V = 5875.9(4) 3, Z = 4, C63H57N7O12Cu3, Mr = 1294.78, Dc = 1.464 g/cm3, m = 1.146 mm-1, F(000) = 2668, R = 0.0784 and wR = 0.1546 for 6926 observed reflections with I > 2s(I). The differences of coordinate bond lengths are observed between anhydrous and hydrous units: in the former unit, the average bond lengths are 1.978 ?for CuN (azomethine), 1.883 ?for CuO (phenolic) in Schiff-base moiety, 1.959 ?for CuO (keto), and 1.919 ?for CuO (hydroxy) in hydroxypyridinone moiety; while those in the latter are longer with the following corresponding values: 1.985(5), 1.908(5), 1.993(5) and 1.919(4) ? respectively. The Cu(2)O (water) bond length is 2.375(6) ?

DFT Study on the Structure of Ionic Liquid 1-Ethyl-3-methylimidazolium Hexafluorophosphate

This paper reports the ab initio and Density Functional Theory (DFT) studies on the structure of the ionic liquid 1-ethyl-3-methylimidazolium hexafluorophosphate ([EMIM]+[PF6]-). Hartree-Fock (HF) and DFT(B3LYP) methods are respectively used to obtain the stable structure of the gas phase ion pair at the 6-311++G(d, p) basis set level. The theoretical IR spectra of [EMIM]+[PF6]- were obtained from the calculated vibrational frequencies and intensities. The changes of atomic charge population have been investigated using Natural Bond Orbital (NBO) analysis. The computational results show that there may exist hydrogen bonds between the cation and the anion. After ZPE and BSSE corrections, the interaction energy between the cation and the anion is –314.44 kJ?mol-1.

Ab Initio Calculation of Room Temperature Ionic Liquid 1-Ethyl-3-Methyl-Imidazolium Chlorocuprate (Ⅰ)

The Hartree-Fock method has been employed to investigate the electronic structures of EMIM^＋（1-ethyl-3-methyl-imidazolium^＋）, CuCl2^-, Cu2Cl3^-, CuCl3^2-, EMIM＋^-CuCl2^-, EMIM^＋-Cu2Cl3^-, and EMIM^＋-CuCl3^2- pairs. Full optimization and frequency analyses of EMIM^＋, CuCl2^-, Cu2Cl3^-, CuC13^-, eight initial EMIM^＋-CuCl2^-, six EMIM^＋-Cu2Cl3^-, and four EMIM^＋-CuCl3^2- geometries have been carried out using Gaussian-94 soft-package at 6-31＋G（d,p） basis set level for hydrogen, carbon, nitrogen, chlorine atoms and Hay-Wadt effective core potential for copper atom. The electronic structures of lowest energy of EMIM^＋-CuCl2^-, EMIM＋-Cu2Cl3^-, EMIM^＋-CuCl3^2-, single EMIM^＋, CuCl2^-, Cu2Cl3^-, and CuCl3^2- have been comparatively studied. The calculated results showed that EMIM^＋-CuCl2^- pair conformer of lowest energy was five ring parallel to Cl-Cu-Cl with 3.2A distance, EMIM^＋-CuCl3^2- pair conformer of lowest energy was five ring parallel to CuCl3^2-plane with 3.4A distance, and the optimized EMIM^＋-Cu2Cl3^- pair conformer of lowest energy was five ring perpendicular to Cl-Cu-Cl-Cu-Cl plane with 3.0A distance between the terminal Cl atoms and the 5-ring of EMIM^＋. The cohesion between cations and anions is brought about by C-H. C1 hydrogen bonds that are reinforced by charge assistance. The frequency analyses suggested that all stationary points are minimum because of no appearing of imaginary frequency. The assigned frequencies were in agreement with the experimental report. The low energy of interaction because of the bulkyasymmetry of EMIM＋ and the charge dispersion of cation and anion leads to the low melting point of the ionic liquids, EMIM^＋-CuCl2^-, EMIM^＋-Cu2Cl3^-, and EMIM^＋-CuCl3^2-. The interaction energy of EMIM^＋-CuCl2^-, EMIM^＋-Cu2Cl3^-, and EMIM^＋-CuCl3^2- is 309.0 kJ/mol, 316.8 kJ/mol, and 320.2 kJ/mol, respectively. The relationship of interaction energy via distance between cations and anions was also investigated by single point energy scan.

Synthesis and Crystal Structure of Ethyl 3-(4-Chlorophenyl)-3,4-dihydro-6-methyl-4-oxo-2-(pyrrolidin-1-yl)furo[2,3-d]pyrimidine-5-carboxylate

The crystal structure of the title compound ethyl 3-（4-chlorophenyl）-3,4-dihydro-6- methyl-4-oxo-2-（pyrrolidin-1-yl）furo[2,3-d]pyrimidine-5-carboxylate （C20H20ClN3O4, Mr= 401.84） has been prepared and determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/n with a = 20.6215（9）, b = 8.5311（4）, c = 21.6886（9） A^°, β = 91.607（1）°, V = 3814.0（3）A^°^3, Z = 8, Dc = 1.400 g/cm^3, F（000） = 1680, μ = 0.233 mm^-1, R = 0.0718 and wR = 0.1545 for 6717 observed reflections with I 〉 2σ（I）. X-ray diffraction analysis reveals two crystallographically independent molecules in the asymmetric unit.

TEXTURES OF ETHYL-ACETYL CELLULOSE MESOPHASE

There was phase separation between the anisotropic and isotropic phases in the ethyl-acetyl cellulose/dichloroacetic acid cholesteric liquid crystalline solutions .The textures of mesophase varied with the concentration. The mesophases could form the disc-like texture, oily streaks texture and texture of domains gathered randomly. In the first two textures the layers of the ordered molecular chain were perpendicular to the slide surface and the axes of the helical structure were parallel to the slide surface.

Synthesis, Crystal Structure and Antimicrobial Activity of (E)-ethyl-4-(2-oxoacenaphthylen-1(2<i>H</i>)-ylideneamino) benzoate

A Schiff base, (E)-ethyl-4-(2-oxoacenaphthylen-1(2H)-ylideneamino)benzoate, (E4AB) had been synthesized in good yield by the acid-catalyzed condensation reaction of acenaphthenequinone and ethyl-4-aminobenzoate in methanolic solution. The synthesized compound was elucidated by elemental analysis (CHN), FTIR, 1H-NMR, 13C-NMR and single crystal X-ray diffraction. E4AB crystallized in the monoclinic crystal system with space group P21/c, Z = 4, V = 1569.3(2) ?3 and unit cell parameters a = 9.1589(8) , b = 21.2003(17)?, c =8.4502(7) ?, β= 106.972(2)°. The crystal structure of the compound is stabilized by intermolecular C-H···O hydrogen bonds and weak intermolecular π···π interactions. The title compound had been tested for the antimicrobial activity against Bacillus subtilis (B. subtilis), Enterobacter and Fusarium oxysporum f. sp. Cubense (Foc) by disc-diffusion method. E4AB is relatively active against Foc which is a pathogen that cause Wilt disease (also well known as Panama disease) in banana plantation.

MECHANISM-TRANSFORMATION SYNTHESIS AND CHARACTERIZATION OF POLY(STYRENE-b-2-ETHYL-2-OXAZOLINE) DIBLOCK COPOLYMER

By mechanism-transformation (anionic --> cationic) poly(styrene-6-2-ethyl-2-oxazoline) diblock copolymer, PS-b-PEOx, was synthesized in two steps. The first step is the polymerization of styrene block capped with ethylene oxide and its tosylation; the second step is the cationic ring-opening polymerization of 2-ethyl-2-oxazoline. The products were thoroughly characterized by various methods, such as H-1-NMR, IR, DMA, TEM and SAXS. The results show that the copolymer obtained possesses high molecular weight and narrow molecular weight distribution.

A Novel Platinum(Ⅳ) Halide Anion as Ethyl-triphenylphosphenonium Salt: Synthetic, Structural and Theoretical Study

A novel platinum（Ⅳ） complex [Ph3PEt]2[PtCl6] 1 obtained from the reaction of H2PtCl6 and [Ph3PEt]I （Ph3PEt^＋ = ethyl-triphenylphosphenonium） has been structurally characterized. It crystallizes in triclinic, space group P1 with a = 10.20850（10）, b = 10.33870（10）, c = 10.814 .A a = 79.453（12）, β = 66.879（ 11 ）, γ = 72.461 （10）°, V = 998.14（9） A^3, Z = 1, Dc = 1.648 g/cm^3, μ（MoKa） = 4.025 mm^-1, F（000） = 490, C40H40Cl6P2Pt, Mr = 990.44, the final R = 0.0270 and wR = 0.0617 for 5787 observed reflections with 1 〉 2σ（Ⅰ）. Structure analysis indicates that the platinum atom almost has the ideal octahedral coordination geometry of PtCl6. The quaternary phosphate cations （Ph3PEt^＋） acting as counter ions are in combination with PtCl6 anions by static attracting forces and H-bonds. Upon the hydrogen bonds existing between cations and anions, the whole structure represents a chain-like construction. Based on the crystal data, quantum chemistry calculation at the DFT/B3LPY level was carded out to reveal the electronic structure of 1.

An experimental study on N-ethyl-N-nitrosourea-induced rat brain gliomas

Rat brain gliomas were induced by transplacental and subcutaneous administration of synthesized Nethyl-N-nitrosourea(EVU, 60 mg/kg body weight) in the late gestational and 3-day Wistar rats respectively, observed until the end of 12th month after administration.The incidences of tumor formation were 73. 2% and 68.3% (those of gliomas were 65. 9% and 63. 4%) respectively. Histologically, the main types were mixed oligodendro-astrocytomas and oligodendrogliomas, with the characteristics of being microfocal, multifocal and mixed, in presence with focal and/or diffuse proliferation of glial cells. The results showed that these glioma models induced by the synthesized ENU were successful and stable, serving a fine approach to further study of the initiation,growth and differentiation of gliomas. The significance of proliferation of glioblasts in the oncogenesis of ENU-induced gliomas was discussed in this report.

Delivery of docetaxel using pH-sensitive liposomes based on D-α-tocopheryl poly(2-ethyl-2-oxazoline) succinate:Comparison with PEGylated liposomes

This study aimed to investigate the ability of the novel materials D-α-tocopheryl poly(2-ethyl-2-oxazoline) succinate(TPOS) to construct pH-sensitive liposomes. TPOS was initially synthesized and characterized by TLC, FTIR, and ~1H-NMR. The buffering capacity of polyethylene glycol-distearoyl phosphatidylethanolamine(PEG-DSPE) and TPOS was determined by acid-base titration, and TPOS displayed a slower downtrend and gentler slope of titration curve than PEG-DSPE within pH 7.4–5.0. Studies on the in vitro drug release demonstrated that TPOS modified docetaxel(DOC) liposomes(TPOS-DOC-L) had a slower drugrelease rate at pH 7.4 similar to PEGylated-DOC liposomes(PEG-DOC-L), whereas the release rate reached approximately 86.92% ± 1.69% at pH 6.4. In vitro cellular uptake assays by microplate reader, and flow cytometry revealed that TPOS modified coumarin 6 liposomes(TPOS-C6-L) had stronger cellular uptake at pH 6.4 than that at pH 7.4( P < 0.01). Conversely, for PEGylated C6 liposomes(PEG-C6-L) and conventional C6 liposomes(C6-L), very similar cellular uptakes were exhibited at different pH values. Confocal laser scanning microscopy images showed that PEG-C6-L and C6-L were mainly located in lysosomes. By contrast, TPOS-C6-L showed broader cytoplasmic release and distribution at 4 h. MTT assay showed that the cytotoxicity of TPOS-DOC-L was similar to that of PEG-DOC-L and conventional DOC liposomes(DOC-L) at the same DOC concentration and at pH 7.4, but was much lower than those at pH 6.4 after 48 h of incubation. The apoptosis of PEG-DOC-L and DOC-L had no remarkable improvement with decreased pH from 7.4 to 6.4. Meanwhile, TPOS-DOC-Lsignificantly induced the apoptosis of HeLa cells with decreased pH. Therefore, TPOS can be a biomaterial for the construction of a pH-sensitive drug delivery system.

Synthesis of (S)-N-(2-Ethyl-6-methylphenyl) alanine by Enzyme-catalyzed Resolution and Chemical Racemization

A practical synthesis of （S）-N-（2-ethyl-6-methylphenyl）alanine, a key intermediate for （S）-metolachlor, was completed by means of lipase-catalyzed hydrolytic kinetic resolution and chemical racemization of the remaining ester. The effects of operating temperature and enzyme concentration on the activity and enantioselectivity of enzyme were initially studied, and it was found that the enantioselectivity of CAL-B towards the resolution was not high enough to obtain enantiomerically pure compound（E=12.1）. When diethyl ether（15%, volume fraction） was added in the reaction medium, the lipase gave an excellent enantioselectivity（E=117.8）, which is about 9.7-fold that in pure buffered aqueous solution. For overcoming the limitation of a maximum theoretical yield of 50%, the acid product was separated from the remaining ester by a simple extraction procedure and the remaining ester was racemized with aldehyde and acetic acid under microwave irradiation or conventional heating condition, The results show the microwave irradiation was more effective than the conventional heating method and gave the desired （R,S）-N-（2- ethyl-6-methylphenyl）alanine methyl ester a high yield（92%） with R/S=50/50 in 1 h.

Synthesis and Crystal Structure of 3-(1-Ethyl-1H-indole-3-carbonyl)aminopropionic Acid

3-（1-Ethyl-1H-indole-3-carbonyl）aminopropionic acid has been synthesized by alkylation of 3-（1H-indole-3-carbonyl）aminopropionic acid methyl ester with bromoethane,follo-wed by saponifying and acidating,in 89.0% yield.Its crystal structure was gotten and determined by X-ray diffraction method.The crystal is of orthorhombic,space group P212121 with a = 8.9490（12）,b = 11.1010（15）,c = 13.0475（18） ,V = 1296.2（3） 3,Z = 4,Dc = 1.334 g/cm3,λ = 0.71073 ,μ（MoKα） = 0.095 mm-1,Mr = 260.29 and F（000） = 552.The structure was refined to R = 0.0306 and wR = 0.1445 for 2612 observed reflections with I 2σ（I）.In the crystal structure,molecules are linked to each other through hydrogen bonds of N（2）-H（2）···O（1） and O（3）-H（3）···O（1）,generating a three-dimensional network.

Generation of pig primary fibroblast cells harboring defective <i>MC</i>4R genes by <i>N</i>-ethyl-<i>N</i>-nitrosourea mutagenesis: A gene-driven, nontransgenic approach to pig improvement

Transgenic pigs have been produced with the aim of further improving pigs in terms of economic and environmental traits, but these animals have not been allowed to enter the food chain. As an alternative approach to generating pigs with novel traits of economic importance that cannot be introduced by conventional breeding, we propose a strategy for combining in vitro mutagenesis of pig primary cells with N-ethyl-N-nitrosourea (ENU) and somatic-cell nuclear transfer (SCNT) technology. To explore the feasibility of this strategy, we treated pig primary fibroblast cells with ENU, estimated the per-base mutation frequency induced by the mutagen, clonally cultured about 4000 of the mutagenized cells, and screened them for mutation within the coding region of the melanocortin-4 receptor (MC4R) gene, a key gene in energy homeostasis. Through this screening, we obtained 14 cell clones, each harboring a heterozygous base change within the coding region for MC4R. Of the mutant cell clones, each of two contained a mutant allele encoding MC4R with greatly reduced receptor activity. By SCNT using these cell clones as donors, pigs harboring mutated MC4R alleles with reduced receptor activity can be produced. Our strategy for generating pigs with novel genetic traits likely will be more acceptable to the public than is the use of transgenic technology.

Synthesis and Crystal Structure of cis-Bis(3-hydroxy2-ethyl-4-pyranonato)dioxomolybdenum(Ⅵ)

The complex MoO2(C7H7O3)2 has been prepared by the reaction of 3-hydroxy- 2-ethyl-4-pyranone with (NH4)6Mo7O244H2O. The single-crystal X-ray study shows that the coordination sphere about the molybdenum atom in the complex consists of six oxygen atoms arranged in a distorted octahedral geometry with the dioxo ligands in cis positions. The crystal is of monoclinic, space group P21/c with a = 8.3968(2), b = 12.7534(4), c = 14.5443(4) ? b = 96.277(1), V = 1548.18(7) ?, Z = 4, C14H14O8Mo, Mr = 406.19, Dc = 1.743g/cm3, m = 0.886mm-1, F(000) = 816, R = 0.0444 and wR = 0.1091 for 2336 observed reflections with I>2s(I). The average Mo=O bond length is 1.695(4) ? The two ketonic oxygen atoms of the pyranone moieties are trans to the oxo ligands and the hydroxy oxygen atoms are trans to each other. The average MoO bond lengths are 2.248(4) ?for the ketone oxygens and 2.005(3) ?for the hydroxy oxygens. The average ligand bite angle of OMoO is 75.2(2) and the bond angle between two Mo=O is 105.1(2). The dihedral angle is 79.16(2)?between two chelate ring planes.