Experimental Investigation on Binary Phase Diagram of the Thermotropic Phase Transitions Compounds (n‐CnH2n+1R3)2ZnCl4

The thermotropic phase transitions compounds (n‐C_nH_2n+1R₃)₂ZnCl₄ as well as a series of their binary mixtures were prepared by a solution reflux method from their ethanol solutions. The experimental subsolidus binary phase diagram of [n‐C₁₈H₃₇N(CH₃)₃]₂ZnCl₄‐[n‐(C₁₈H₃₇)₂N(CH₃)₂]₂ZnCl₄ is constructed over the entire composition range by differential scanning calorimetry(DSC) and X‐ray. Experi‐ mental results indicate one stable intermediate phase [n‐C₁₈H₃₇N(CH₃)₃] [n‐(C₁₈H₃₇)₂N(CH₃)₂]ZnCl₄ at W_C18C3Zn %=59.75 %, and two invariant three phase equilibria, which shows two eutectoid temperatures: Te₁ at 310±1 K for eutectoid point W_C18C3Zn %=36.24 %, Te₂ at 313±1 K for eutectoid point W_C18C3Zn %=80.17 %. These three noticeable solid‐solution ranges are α‐phase at the left, ?‐phase at the right, and ψ‐phase in the middle of the phase diagram. It is (n‐C_nH_2n+1R₃)₂ZnCl₄ systems as phase change materials that are characterized the phase transition temperatures T in the range of 310 to 340 K, the transition enthalpies ΔH in the range of 38.40 and 168.72 J/g between two polymorphic forms.     

Paecilomycines A and B,Novel Diterpenoids,Isolated from Insect‐Pathogenic Fungi Paecilomyces sp. ACCC 37762

Two new diterpenoids, named paecilomycine A ( 1 ) and paecilomycine B ( 2 ), including a novel skeleton with a five‐membered lactone ring, together with three known labdane diterpenoids, rel‐(1R,3S,4aS,5R,8aS)‐5‐[(3E)‐4‐carboxy‐3‐methylbut‐3‐en‐1‐yl]decahydro‐3‐hydroxy‐1,4a‐dimethyl‐6‐methylidenenaphthalene‐1‐carboxylic acid ( 3 ), botryosphaerin E ( 4 ), and agathic acid ( 5 ), were isolated from solid culture of the insect pathogenic fungi strain Paecilomyces sp. The structures of all compounds were established on the basis of comprehensive spectroscopic studies. The relative configurations of 1 and 2 were determined by single‐crystal X‐ray diffraction analyses.     

The topology of the Ehrenfest force density revisited. A different perspective based on Slater‐type orbitals

The topology of the Ehrenfest force density was studied with Slater‐type orbitals (STO). At larger distances from the nuclei, STOs generate similar artefacts as noticed before with Gaussian‐type orbitals. The topology of the Ehrenfest force density was found to be mainly homeomorphic with the topology of the electron density. For the first time, reliable integrations of several properties over force density atomic basins were performed successfully. Integration of the electron density of a number of hydrides, fluorides, and chlorides of first row elements over force density basins indicate substantial differences between the partial charges of the atoms as compared with those obtained from electron density basins. Calculations on saturated hydrocarbons confirm that the electronegativity of carbon atoms increases with increasing geometrical strain. Atomic interaction lines are observed to exist in the Ehrenfest force density between the hydrogen atoms of several so‐called “congested” molecules, and also in some inclusion complexes of alkanes with helium. However, interaction lines are lacking in several other controversial cases. © 2015 Wiley Periodicals, Inc.     

Chemical investigation of metabolites produced by an endophytic Aspergillus sp. isolated from Limonia acidissima

Endophytic fungi are considered as a good source to produce important secondary metabolites with interesting bioactivities. In a continuation of our studies towards the search for environmentally friendly bioactive compounds from Sri Lankan flora, we investigated the secondary metabolites produced by the endophytic fungi Aspergillus sp. isolated from the seeds of the popular edible fruit Limonia acidissima L. of the family Rutaceae. The pure culture of the Aspergillus sp. was grown on potato dextrose broth media. After 4 weeks fermentation, fungal media were extracted with organic solvents. Chromatographic separation of the fungal extracts over silica gel, Sephadex LH-20 and RP-HPLC furnished flavasperone (1), rubrofusarin B (2), aurasperone A (3), fonsecinone D (4) and aurasperone B (5). Compounds 1–4 showed moderate activities in brine shrimp toxicity assay. This is the first report of the ¹³C NMR data of compounds 4 and 5.     

基于罗丹明B的激活型α-酮戊二酸荧光探针

α-酮戊二酸(α-KA)是人体三羧酸循环的一个重要代谢中间体,异柠檬酸脱氢酶-1(IDH1)及异柠檬酸脱氢酶-2(IDH2)的突变将导致α-KA转化为2-羟基戊二酸(2HG),该过程与急性骨髓性白血病(AML)密切相关,因此检测人体内α-KA的含量变化具有重要意义。本文以罗丹明B作为荧光基团,通过将罗丹明B与水合肼反应得到能够检测α-KA的荧光增强型探针RBN,并优化了检测温度、pH及响应时间等条件。研究表明,RBN对α-KA表现出很好的选择性,不受人体内常见氨基酸、化学结构类似的羰基化合物及活性氧化物(ROS)的影响,具有潜在的应用价值。     

Insights into the nature of X(3872) through B meson decays

We study the \begin{document}$ B_{c,u,d}\to X(3872)P $\end{document} decays in the perturbative QCD (PQCD) approach, involving the puzzling resonance \begin{document}$ X(3872) $\end{document}, where P represents a light pseudoscalar meson (K or π). Assuming \begin{document}$ X(3872) $\end{document} to be a \begin{document}$ 1^{++} $\end{document} charmonium state, we obtain the following results. (a) The branching ratios of the \begin{document}$ B^+_c\to X(3872)\pi^+ $\end{document} and \begin{document}$ B^+_c\to X(3872) K^+ $\end{document} decays are consistent with the results predicted by the covariant light-front approach within errors; however, they are larger than those given by the generalized factorization approach. (b) The branching ratio of the \begin{document}$ B^+\to X(3872)K^+ $\end{document} decay is predicted as \begin{document}$ (3.8^{+1.1}_{-1.0})\times10^{-4} $\end{document}, which is smaller than the previous PQCD calculation result but still slightly larger than the upper limits set by Belle and BaBar. Hence, we suggest that the\begin{document}$ B^{0,+}\to X(3872)K^{0,+} $\end{document} decays should be precisely measured by the LHCb and Belle II experiments to help probe the inner structure of \begin{document}$ X(3872) $\end{document}. (c) Compared with the \begin{document}$ B_{u,d}\to X(3872)K $\end{document}decays, the \begin{document}$ B_{u,d}\to X(3872)\pi $\end{document} decays have significantly smaller branching ratios, which drop to values as low as \begin{document}$ 10^{-6} $\end{document}. (d) The direct CP violations of these considered decays are small (\begin{document}$ 10^{-3}\sim 10^{-2} $\end{document}) because the penguin contributions are loop suppressed compared to the tree contributions. The mixing-induced CP violation of the \begin{document}$ B\to X(3872)K^0_S $\end{document} decay is highly consistent with the current world average value \begin{document}$ \sin2\beta=(69.9\pm1.7)$\end{document}%. Experimentally testing the results for the branching ratios and CP violations, including the implicit \begin{document}$S U(3)$\end{document} and isospin symmetries of these decays, helps probe the nature of \begin{document}$ X(3872) $\end{document}.     

Identification of metabolites of Ginkgolide B in vivo and in vitro using ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry

Ginkgolide B is a dietary diterpene with multiple pharmacological activities. However, current research on ginkgolide B is not comprehensive. The current study analyzed the metabolic profile of ginkgolide B in vivo and in vitro using ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry. To detect and identify the different metabolites in ginkgolide B, a novel data processing method was used as an assistant tool. A total of 53 different metabolites of ginkgolide B (38 phase I metabolites and 15 phase II metabolites) were detected relative to blank samples. The biotransformation route of ginkgolide B was identified as oxidation, dehydroxylation, hydrogenation, decarbonylation, demethylation, sulfate conjugation, glucose conjugation, methylation, and acetylation. The current study demonstrated a method for rapidly detecting and identifying metabolites and provided useful information to further characterize the pharmacology and mechanism of ginkgolide B. A method for the analysis of other diterpene metabolic components in vivo and in vitro was also established.     

铬-对苯二甲酸MOF的框架异构：MIL-88B(Cr)和MIL-101(Cr)

可以通过简单地控制乙酸浓度的方法,在相似的水热合成条件下合成2种同一家族的金属有机框架材料(MOFs):MIL-88B(Cr)和MIL-101(Cr)。在相对较低的乙酸浓度下,可以得到平均粒径为100 nm的MIL-101(Cr),并拥有很高的BET比表面积(3543 m^2·g^-1)。而在相对较高的乙酸浓度下,则可得到另一种具有“呼吸”特性结构的MOF——MIL-88B(Cr)。利用粉末X射线衍射、扫描电镜、N2吸附-脱附分析、热重分析等对它们的结构、形貌、孔隙率等性质做了详细的分析。     

Cobalt and nitrogen atoms co-doped porous carbon for advanced electrical double-layer capacitors

Electrical double-laye r capacitors are widely concerned fo r their high power density,long cycling life and high cycling efficiency.However,their wide application is limited by their low energy density.In this study,we propose a simple yet environmental friendly method to synthesize cobalt and nitrogen atoms co-doped porous carbon(CoAT-NC) material.Cobalt atoms connected with primarily pyridinic nitrogen atoms can be uniformly dispersed in the amorphous carbon matrix,which is benefit for improving electrical conductivity and density of states of the carbon material.Therefore,an enhanced perfo rmance is expected when CoAT-NC is served as electrode in a supercapacitor device.CoAT-NC displays a good gravimetric capacitance of 160 F/g at 0.5 A/g combing with outstanding capacitance retention of 90% at an extremely high current density of 100 A/g in acid electrolyte.Furthermore,a good energy density of30 Wh/kg can be obtained in the organic electrolyte.     

Hyperterpenoids A and B: Two pairs of unprecedented 6/6/4/6/6 polycyclic cyclobutane meroterpenoids with potent neuroprotective and anti-inflammatory activities from Hypericum beanii

Hyperterpenoid A (1) and B (2), two pairs of enantiomers, with an unprecedented 6/6/4/6/6 polycyclic skeleton, along with one known compoud hypermonone A (3) were isolated from Hypericum beanii. The racemate (±)-1 and (±)-2 were successfully separated into the two optically pure enantiomers (ee ≥ 99%) using a preparative HPLC system. Their absolute configurations were elucidated by extensive spectroscopic analyses and single-crystal X-ray diffraction method. The related plausible biogenetic pathways were presented. Compound 1-3 showed significant neuroprotective activity and potential anti-inflammatory activity. The result that (+)-2 and (-)-2 presented different anti-inflammatory properties, may lead us to new discovery of structure activity relationship between racemates, enantiomers, and diastereomers, as well as further research regarding the binding of drugs to target proteins.