Mixed micelles of binary surfactant mixtures Tween 40 – Na-3,12-dioxo-5β-cholanate and Tween 80 – Na-3,12-dioxo-5β-cholanate and their thermodynamic description and characterization

Regular solution theory (RST) was compared with model-independent thermodynamical methods (MIM) to analyze binary mixed micelles. It was found that if the molar fractions of the surfactants obtained using RST and MIM do not differ, the binary mixed micelles are symmetrical, according to the excess Gibbs energy. The algorithm used to analyze the binary surfactant mixtures, i.e., the method for determining whether the binary mixture of the surfactants is symmetrical and obeys RST, was developed.Binary mixtures of Tween 40 – Na-3,12-dioxo-5β-cholanate (T40-3,12-DOC) and Tween 80 – Na-3,12-dioxo-5β-cholanate (T80-3,12-DOC) were analyzed. Mixed micelles of T40-3,12-DOC were found to be more stable compared with the hypothetical ideal mixed micelles, i.e., they are primarily symmetrical, according to the excess Gibbs energy, but they do not obey RST. Mixed micelles of T80-3,12-DOC were non-symmetrical, according to the excess free energy, and were less stable then the ideal mixed micelles. With the increase in the molar fraction of T80 in the mixed micelle, the micelle became less stable and decomposed into micelles that comprised the building units.     

Development of isoxazoline-containing peptidomimetics as dual αvβ3 and α5β1 integrin ligands

Isoxazoline-containing peptidomimetics, designed to be effective α(v)β(3) and α(5)β(1) integrin ligands, were synthesized through an original procedure involving N,O-bis(trimethylsilyl)hydroxyamine conjugate addition to alkylidene acetoacetates, followed by intramolecular hemiketalization. To mimic the RGD recognition sequence, basic and acidic terminal appendages were introduced, and the final products were tested in cell adhesion inhibition assays. All the synthesized compounds proved to be excellent ligands for both integrin receptors, and a strong influence on intracellular signaling and phosphorylation pathways was demonstrated by evaluation of fibronectin-induced phosphorylation of ERK. The molecular basis of the observed inhibitory activity was suggested on the results of docking experiments.     

Preparation and characterization of poly-carboxymethyl-β-cyclodextrin superplasticizer

A new superplasticizer of poly-carboxymethyl-β-cyclodextrin (PCM-β-CD) was prepared by ring-opening polymerization of epoxy chloropropane and CM-β-CD using sodium hydroxide as initiator. The structure of PCM-β-CD was characterized by FTIR and NMR as well as GPC. The performances of the CM-β-CD were tested by measuring paste luidity, setting time, adsorption and zeta-potential. The result showed the performances of PCM-β-CD closed to the control polycarboxylate superplasticizer (PCs) used in this study, especially the fluidity loss is smaller and the setting time is longer than the PCs. The reason might be the synergism of the steric hindrance with the hollow truncated cone and the electrostatic repulsion from –COO^? groups. The mechanism of dispersion and retardation by PCM-β-CD was elucidated based on the results of adsorption properties and zeta‐potential of the cement particles. The study offers a new approach to synthesize superplasticizer based on β-CD and an alternative to concrete engineering.     

β-Galactosidase-instructed formation of molecular nanofibers and a hydrogel

Here we report the first example of using β-galactosidase to trigger the formation of cell compatible, supramolecular nanofibers, which ultimately may lead to a new approach for the development of soft nanotechnology.     

Preparation and properties of eggshell/β-polypropylene bio-composites

In this article, a novel eggshell/β-PP bio-composite was prepared and evaluated. First the waste chicken eggshell (ES) was modified by a stingy amount of pimelic acid (PA) through solution method, and then compounded with PP through melt blending method. The crystalline form, mechanical properties, and morphology of the ES/β-PP composites were studied. The results showed that ES modified by PA was a β nucleating agent with high efficiency and selectivity, resulting in the maximum K_β value of 0.99 in PP composites. PA modification promoted the dispersion and interfacial bonding of ES in PP. Although the addition of PA-modified ES slightly decreased tensile properties and flexural properties of PP, it increased the impact strength of PP by 228% than that of pure PP. Taking all factors into consideration, the optimal mass ratio of PP/ES/PA composites for reaching optimum mechanical properties should be 100/5/0.000471. Thus, the application of modified ES to prepare ES/β-PP bio-composites represents a promising way to mitigate environmental pollution and to reduce the cost of polyolefin products. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Elevated Levels of Lewis Y and Integrin α5β1 Correlate with Chemotherapeutic Drug Resistance in Epithelial Ovarian Carcinoma

Objective

To measure Lewis y and integrin α₅β₁ expression in epithelial ovarian carcinoma and to correlate the levels of these molecules with ovarian carcinoma chemotherapy and prognosis.

Methods

The study population included 34 ovarian carcinoma patients with chemotherapeutic drug-resistance, six partially drug-sensitive cases, and 52 drug-sensitive cases (92 total). Immunochemistry was used to determine expression of Lewis y antigen and integrin α₅β₁ in ovarian carcinoma tissues, and correlation of these molecules with chemotherapy resistance was further investigated, Multi-factor logistic regression analysis was applied to investigate: age, surgical stage, grade, subtype of patient cases, metastasis of lymph nodes, residual tumor size, expression levels of Lewis y antigen and integrin α₅β₁ correlation with ovarian carcinoma chemotherapy resistance.

Results

The expression rates of Lewis y antigen and integrins α₅ and β₁ were significantly greater in the drug-resistant group (91.17%, 85.29%, 88.24%) than the partially sensitive (50.00%, 33.33%, 50.00%) or sensitive groups (61.54%, 57.69%, 55.77%). Binary logistic regression analysis revealed that surgical stage, residual tumor size, and expression of integrin α₅ and Lewis y in ovarian carcinoma tissues were independent risk factors for chemotherapeutic drug resistance.

Conclusions

Overexpression of Lewis y and integrin α₅ are strong risk factors for chemotherapeutic drug resistance in ovarian carcinoma patients.     

高效液相色谱法测定非那雄胺中5β-非那雄胺

目的：建立高效液相色谱方法用于测定非那雄胺原料药中的5β-非那雄胺。方法：采用Welch Xtimate C18(4.6×150 mm,3.5μm色谱柱,以8%的四氢呋喃水溶液为流动相A,以8%的四氢呋喃乙腈溶液为流动相B,梯度洗脱,流速为1.0 mL/min,检测波长为210nm,柱温25℃,对非那雄胺原料药中的5β-非那雄胺进行定量分析。结果：该液相色谱方法中5β-非那雄胺与非那雄胺及相邻杂质分离良好,且非那雄胺原料药在各强制破坏条件下均未产生干扰5β-非那雄胺的杂质,方法专属性良好;5β-非那雄胺与非那雄胺分别在0.27～2.17和0.28～2.23μg·mL^-1浓度范围内线性良好(r≥0.990);5β-非那雄胺的加样回收率为108.2%;进样精密度和重复性良好;系统适用性溶液和供试品溶液室温条件放置94小时和82小时稳定;各耐用性条件下5β-非那雄胺与非那雄胺的分离度均在4.10～4.80之间,方法耐用性良好。结论：本文所建立的分析方法专属性好、准确度高,简便耐用,可用于非那雄胺原料药中5β-非那雄胺的定量分析。     

Occurrence of 5α-cholesta-7,24-dien-3β-ol and 23-dehydrolophenol in the bean lipids of Vanilla madagascariensis

Eleven 4-desmethylsterols, four 4,4-dimethylsterols, and twelve 4-methylsterols were identified in Vanilla madagascariensis beans. The 4-desmethylsterol fraction was characterized by a high level of 5α-cholesta-7,24(25)-dien-3β-ol (35.3%). The 4-methylsterol fraction was characterized by a high level of 31-norcycloartenol (57.5%) and the presence of 23-dehydrolophenol (9.4%). Cycloartenol (72.9%), cyclosadol (12.7%), parkeol (9.7%), and 24-dehydrotirucallol (4.7%) were identified in the 4,4-dimethylsterol fraction.     

Synthesis and dissolution behavior of β-TCP and HA/β-TCP composite powders

Calcium phosphate powders, β-TCP and biphasic HA/β-TCP, were synthesized by calcining the powders obtained from the co-precipitation method using Ca(NO₃)₂·4H₂O and (NH₄)₂HPO₄. The effects of the initial Ca/P ratio and pH of the solution on the phase evolution and in vitro dissolution behavior of the powders in a Ringer's solution were investigated. The Ca/P ratio of the resulting powders was strongly dependent on the pH of the solution and weakly dependent on the initial Ca/P ratio. Single phase TCP powder was obtained at pH=7.4 and the initial Ca/P ratio had a little effect on the resulting Ca/P ratio. Biphasic composite powders were prepared at pH=8.0 and the Ca/P ratio of resulting powder was controllable by adjusting the initial Ca/P ratio. TCP powder showed the highest dissolution rate in the Ringer's solution and biphasic composite powder exhibited an intermediate dissolution behavior between that of HA and TCP.     

Acid-catalyzed isomerization of fucosterol and Δ5-avenasterol

This work shows that fucosterol, Δ⁵-avenasterol, and similar ethylidene-side chain sterols can undergo acid-catalyzed isomerization to give a mixture of five isomers. Four isomers formed from fucosterol were analyzed, using gas chromatography-mass spectrometry, and were characterized as Δ⁵-avenasterol two Δ^5,23-stigmastadienols, and Δ^5,24(250)-stigmastadienol. When the unsaponifiables fraction from oat oil was subjected to acid hydrolysis, the two Δ^5,23-stigmastadienol isomers and Δ^5,24(25)-stigmastadienol were detected while fucosterol coeluted with sitosterol. Interisomerization of ethylidene-side chain sterols represents a limitation to the use of the acid hydrolysis method in the determination of sterols in food and other plant materials rich in these sterols, e.g., oat lipids.     

Propane Aromatization over HZSM‐5 and Ga/HZSM‐5 Catalysts

The selective transformation of light alkanes to aromatics that are more valuable and versatile feedstocks for the chemical industry is one of the major challenges of catalytic chemistry. The complexity of the aromatization chemistry makes it difficult to unravel reaction mechanisms and, mechanistic information is largely developed from observed product distributions. This article reviews the current mechanistic understanding for the conversion of propane to aromatic compounds over HZSM‐5 and Ga/HZSM‐5 catalysts based on experimental as well as theoretical studies.

Following a general discussion of acidity and confinement effects in these systems, this review focuses on understanding specific reactions occurring on Brønsted acid sites in HZSM‐5. Mechanistic details available from Density Functional Theory (DFT) calculations, as well as kinetic modeling efforts for various complex hydrocarbon systems are critically reviewed. A detailed, tabulated review of the literature compares the catalytic performance of gallium modified ZSM‐5 catalysts and subsequently the promotional effect of gallium as an additive is critically discussed in terms of the nature of the active sites, as well as the new reaction pathways introduced by gallium addition.     

Synthesis and evaluation of 1-amino-6-halo-β-carbolines as antimalarial and antiprion agents

Malaria is one of the world's most devastating parasitic diseases, causing almost one million deaths each year. Growing resistance to classical antimalarial drugs, such as chloroquine, necessitates the discovery of new therapeutic agents for successful control of this global disease. Here, we report the synthesis of some 6-halo-β-carbolines as analogues of the potent antimalarial natural product, manzamine A, retaining its heteroaromatic core whilst providing compounds with much improved synthetic accessibility. Two compounds displayed superior activity to chloroquine itself against a resistant Plasmodium falciparum strain, identifying them as promising leads for future development. Furthermore, in line with previous reports of similarities in antimalarial and antiprion effects of aminoaryl-based antimalarial agents, the 1-amino-β-carboline libraries were also found to possess significant bioactivity against a prion-infected cell line.     

Zirconocene complexes of the sterically demanding pentaphenylcyclopentadienyl ligand,CpPRO. Synthesis and characterization of CpPROZrCl3 and CpCpPROZrCl2 (Cp=η5-C5H5; CpPRO=η5-C5(C6H5)5)

The synthesis, characterization and X-ray structures of two zirconium complexes of the bulky pentaphenylcyclopentadienyl ligand, Cp^PRO, are reported. The monocyclopentadienyl 12 electron complex, Cp^PROZrCl₃ (I), has an unusual monomeric structure in the solid state and has short Zr–ligand distances. The Lewis acidity of this complex is manifested in its ability to catalyze the [4+2] cycloadditions of methyl- and ethylmethacrylate to cyclopentadiene. The sandwich complex, Cp^PROCpZrCl₂ (II), has more typical Zr–ligand distances, but has a more parallel arrangement of the two cyclopentadienyl rings.     

Functionalization of unactivated carbons in 3α,6- and 3α,24-dihydroxy-5β-cholane derivatives by dimethyldioxirane

Direct remote functionalization of unactivated carbons by dimethyldioxirane (DMDO) was examined for 3α,6- and 3α,24-dihydroxy-5β-cholane derivatives. DMDO oxidation of stereoisomeric methyl 3α,6-diacetoxy-5β-cholanoates caused the direct, unexpected 14α- and 17α-hydroxylations, in analogy with that of the 5α-H analogs, regardless of the differences in stereochemical configuration of the A/B-ring junction and of the acetoxyl groups at C-3 and C-6. On the other hand, the ester derivatives of 3α,24-dihydroxy-5β-cholane with DMDO were transformed into the corresponding 5β-, 14α-, and 17α-hydroxy compounds, whereas the ether derivatives yielded the 5β-hydroxy, 3-oxo, and C-24 oxidized products, accompanied by their dehydrated ones.     

3β-羟基-15β,16β亚甲基-17β-螺(环氧乙烷)-雄甾-5-烯的合成

三甲锍硫酸甲酯是一种新型的硫叶立德试剂,将其应用于医药中间体3β羟基-15β,16β亚甲基-17β-螺(环氧乙烷)-雄甾-5-烯的合成中,使用三甲锍硫酸甲酯,其催化剂为固体粉末KOH,而不像其它硫叶立德试剂要用昂贵的NaH作催化剂.成功的合成了目标化合物.产率75.6%,反应条件温和,利于工业化生产,产物经IR,1H-NMR、13C-NMR、MS确定.     

Crystallization and morphology of poly(ethylene succinate) and poly(β-hydroxybutyrate) blends

Summary The melting and crystallization behavior of poly(β-hydroxybutyrate) (PHB) and poly(ethylene succinate) blends has been studied by differential scanning calorimetry and optical microscopy. The results indicate that PHB and PES are miscible in the melt. Consequently the blend exhibits a depression of the melting temperature of both PHB and PES. In addition, a depression of the equilibrium melting temperature of PHB is observed. The Flory-Huggins interaction parameter (χ₁₂ ), obtained from melting point depression data, is composition dependent, and its value is always negative. Isothermal crystallization in the miscible blend system PES/PHB is examined by polarized optical microscope. The presence of the PES component gives a wide variety of morphologies. The spherulites exhibit a banded structure and the band spacing decreases with increase PES content. Received: 29 June 1998/Revised version: 31 August 1998/Accepted: 10 September 1998     

Synergistic toughening of epoxy resin by CTBN and CM-β-CD

Carboxymethyl-β-cyclodextrin (CM-β-CD) and carboxyl terminated liquid nitrile rubber (CTBN) were used as binary component fillers in toughening the epoxy resin (E-54). For a single component filler system, the addition of CTBN resulted in significantly improved fracture toughness but reduction of glass transition temperature (T_g) and modulus of epoxy resin. On the other hand, the addition of CM-β-CD resulted in a modest increase in modulus and T_g, and significant improvement in toughness. This work provides a promising route of nanocomposites with excellent toughness. Besides the mechanism of synergistic toughening in this project was explained, and the major toughening mechanisms were attributed to interfacial micro-cracks, energy dissipation of CM-β- CD. This work gives us a further understanding of the modification effect of β- CD.     

Z5-G菌生产聚β-羟基丁酸发酵动力学模型

研究了Z5 G菌株在 3L搅拌发酵罐中以蔗糖为碳源分批发酵生产聚β 羟基丁酸 (PHB)的生长特性。在Lo gistic方程和Luedeking Piret方程的基础上,建立了Z5 G菌发酵过程中菌体生长、基质消耗、产物形成的动力学模型。应用MathCAD软件处理实验数据和模型,拟合出所有模型参数,建立了动力学模型,经过验证模型预测值和实验值吻合较好,表明此动力学模型对指导PHB的发酵生产具有实际意义。