Anderson型和Waugh型杂多阴离子的电子结构及其催化性…

使用ＳＣＣ－ＤＶ－Ｘａ法研究了两种杂多阴离子－－（ＩＭｏ６Ｏ２４）＾５－（Ａｎｄｅｒｓｏｎ型）和（ＮｉＭｏ９Ｏ３２）＾６－（Ｗａｕｇｈ型）的电子结构，并探讨了它们的催化性能。结果表明，两类杂多阴离子均具有催化活性，但不如Ｋｅｇｇｉｎ结构强，（ＩＭｏ＾Ｏ２４）＾５－的催化活性中心是端氧Ｏｔ和中心八面体氧Ｏｔ（ＮｉＭｏ９Ｏ２４）＾６－的催化活性中心是一配位端氧Ｏｔ、四配位中心氧中心杂原子Ｎｉ，两类杂多     

稀土元素1∶6系列钼钴酸盐的合成与性质研究

首次合成了具有Ａｎｄｅｒｓｏｎ 结构的稀土元素钼钴杂多酸盐Ｌｎ［ＣｏＭｏ６Ｏ２４Ｈ６］·ｘＨ２Ｏ，（Ｌｎ ＝ Ｌａ，Ｃｅ，Ｐｒ，Ｎｄ，Ｇｄ，ｘ＝ ７ ～１０）．此类化合物属Ａｎｄｅｒｓｏｎ 结构的Ｂ型，其特点是杂原子与６ 个—ＯＨ 相连形成八面体．通过ＩＣＰ，ＩＲ，ＵＶ，ＴＧ－ ＤＳＣ，ＣＶ，ＸＲＤ 等方法对产物进行了表征     

Keggin结构钼锗稀土杂多蓝的合成、性质及抗病毒活性研究

采用电解法合成了一系列Ｋｅｇｇｉｎ结构钼锗稀土二电子ＬｎＨ３「ＧｅＭｏ１２Ｏ４」．ｎＨ２ｏ和四电子ＬｎＨ５「ＧｅＭｏ１２Ｏ４０」．ｎＨ２Ｏ杂多蓝（Ｌｎ＝Ｌａ，Ｃｅ，Ｐｒ，Ｎｄ，Ｓｍ，Ｅｕ，Ｇｄ）。通过ＩＲ、ＵＶ－Ｖｉｓ，ＤＴＡ，ＸＰＳ和ＥＳＲ等方法对产物进行了表征，确认杂多蓝仍保持Ｋｅｇｇｉｎ结构，但结构有轻微的畸变，研究了Ｐｒ（２）具有很好的抗病毒活性，甚至超过阳性对照药物病毒唑的抗病毒效果，比较两种给药途径，结果发现，腹腔注射优于口服给药的抗病毒效果。     

取代型钨镓杂多配合物的导电性及其磁性

合成了过渡金属取代的钨镓杂多配合物α－Ｎａ７「ＧａＷ１１Ｃｏ（Ｈ２Ｏ）Ｏ３９」．１６Ｈ２Ｏ，α－Ｎａ７Ｈ２「ＧａＷ１０Ｃｏ２（Ｈ２Ｏ）２Ｏ３９」．１６Ｈ２Ｏ和α－ＮａｎＨｍ「ＧａＷ９ＭＥ（Ｈ２Ｏ）３Ｏ３７」．１６Ｈ２Ｏ「Ｍ＝Ｃｏ（Ⅱ），Ｎｉ（Ⅱ，）Ｖ（Ⅴ）」，通过红外，紫外，ＩＣＰ，ＴＧ－ＤＴＡ，ＥＰＲ，ＸＰＳ，＾１８３ＷＮＭＲ，极谱等手段进行了表征。     

分子筛笼内铂羰基簇合物在CO＋NO反应中的催化研究

研究了ＮａＹ分子筛超笼内包容的Ｐｔ羰基簇合物催化剂在ＣＯ＋ＮＯ反应中的催化性能。「Ｐｔ１２（ＣＯ）２４」＾２－／ＮａＹ和「Ｐｔ９（ＣＯ）１３」＾２－／ＮａＹ在此反应中表现出比较高的活性。Ｎ２Ｏ被认为是ＣＯ＋ＮＯ反应的中间产物，同时笼内羰基簇合物还表现了比ＳｉＯ２负载的簇合物好的热稳定性，动力学研究表明，在「Ｐｔ１２（ＣＯ）２４」＾２－／ＮａＹ上，ＮＯ被还原和Ｎ２Ｏ生成的反应级数，相对于ＣＯ分压为小     

含固氮酶钼微环境结构单元O_3MoS_3的Mo－S，Mo－Fe－S化合物的研究

研究了含固氮酶钼微环境Ｏ_３ＭｏＳ_３结构单元四个系列化合物［Ｍｏ（Ｓ，Ｏ－Ｃ_６Ｈ_４－１，２］~－（Ｍ）［Ｍｏ_２（ＣＯ）_３（Ｓ，Ｏ－Ｃ_６Ｈ_４－１，２）_３］~（２－）（Ｄ），［Ｍｏ_３（ＣＯ）_７（Ｓ，Ｏ－Ｃ_６Ｈ_４－１，２）_３］~（２－）（Ｔ），和［Ｍｏ_２Ｆｅ（ＣＯ）_４（Ｓ，Ｏ－Ｃ_６Ｈ_４－１，２）_３Ｃｌ_２］~（２－）（Ｔ_ｆ）的合成化学与结构化学，并通过Ｘ－射线光电子能谱，红外光谱和电化学环伏安研究，深入探讨了它们的混合价，电子迁移和电化学行为，也讨论了有趣的Ｏ_３ＭｏＳ_３结构单元。     

[Fe（CN）6]^4—还原trans—[Co（en）2（ImH02]^3＋的电子转移反应 …

在不同的温度下，考察了六氰合铁配阴离子「Ｆｅ（ＣＮ）５」＾４－还原ｔｒａｎｓ－「Ｃｏ（ｅｎ）２（ＩｍＨ０２」＾３＋的反应动力学。结果表明，反应遵循Ｈ．Ｔａｕｂｅ所提出的外配位界电子传递机理。在２５℃，Ｉ＝０．５ｍｏｌ．Ｌ＾－１，ｔｒａｎｓ－「Ｃｏ（ｅｎ）２（ＩｍＨ）２」＾３＋／「Ｆｅ（ＣＮ）６」＾４－反应体系的前驱配合物离子对形成常数为Ｑ１ｐ＝９８．９ｍｏｌ＾－１．Ｌ，电子转移速率常数为Ｋｍ＝１．     

有机金属化合物中二级化学键的理论研究（Ⅲ）：金属原子簇…

应用ＩＣＯＮ８（ＥＨＭＯ）分子轨道方法，讨论了金属原子簇化合物离子「Ｍ３（ＣＯ）９ＣＣＯ」＾２－（Ｍ＝Ｆｅ，Ｒｕ，Ｏｓ」的结构异性及配体在金属原子基平面上的取向，并表明了二级化学键的存在。     

Co－Mo／TiO_2和C0－M0／γ－Al_2O_3加氢脱硫催化剂的研究

本文考察了ＣｏＭｏ／ＴｉＯ３和ＣｏＭｏ／γ－Ａｌ２Ｏ３催化剂的加氢脱硫性能及表面结构变化和预处理条件对其活性的影响．担体ＴｉＯ２（Ａ）和ＴｉＯ２（Ｂ）分别采用ＴｉＣｌ４中和法和ＴｉＯＳＯ４水解法制备．结果表明，催化剂的活性顺序为ＣｏＭｏ／ＴｉＯ２（Ａ）＞ＣｏＭｏ／ＴｉＯ２（Ｂ）＞ＣｏＭｏ／γ－Ａｌ２Ｏ３催化剂的预处理条件对催化剂的加氢脱硫（ＨＤＳ）和加氢（ＨＹＤ）活性有很大影响，ＴｉＯ２担体上Ｍｏ物种主要以八面体配位构型存在，Ｍｏ６＋更易于还原成低价态．     

穴状稀土杂多化合物的生物活性研究

报道了以「ＴｂＡｓ４Ｗ４０Ｏ１４０」＾２５－及「ＰｒＳｂ９Ｗ２１Ｏ８６」＾１６－为代表的穴状稀土杂多阴离子的体外、体内抗肿瘤活性及体内抗ＲａｕｓｃｈｅｒＭｕＬＶ和ＬＰ－ＢＭ５ＭｕＬＶ病毒活性。以上化合物对Ｈ２２,Ｂ１６,ＨＬ－６０及活体直肠癌、乳腺癌细胞有抑制作用,能减轻荷瘤鼠的瘤重及延长期存活时间及荷病毒鼠的脾重。     

Electronic Metal–Support Interactions in Single‐Atom Catalysts

The synthesis of single‐atom catalysts and the control of the electronic properties of catalytic sites to arrive at superior catalysts is a major challenge in heterogeneous catalysis. A stable supported single‐atom silver catalyst with a controllable electronic state was obtained by anti‐Ostwald ripening. An electronic perturbation of the catalytic sites that is induced by a subtle change in the structure of the support has a strong influence on the intrinsic reactivity. The higher depletion of the 4d electronic state of the silver atoms causes stronger electronic metal–support interactions, which leads to easier reducibility and higher catalytic activity. These results may improve our understanding of the nature of electronic metal–support interactions and lead to structure–activity correlations.     

Synthesis and Anti‐tumor Evaluation of Novel C‐37 Modified Derivatives of Gambogic Acid

Gambogic acid (GA, 1 ), the most prominent representative of Garcinia natural products, has been reported to be a promising anti‐tumor agent. In order to further explore the structure‐activity relationship of GA and discover novel GA derivatives as anti‐tumor agents, 17 novel C‐37 modified derivatives of GA were synthesized and evaluated for their in vitro anti‐tumor activities against A549, HCT‐116, BGC‐823, HepG2 and MCF‐7 cancer cell lines. Among them, 11 compounds were found to be more potent than GA against some cancer cell lines. Notably, compound 8 was almost 5–10 folds more active than GA against A549 and BGC‐823 cell lines with the IC₅₀ values of 0.12 µmol·L^?1 and 0.57 µmol·L^?1, respectively. Chemical modification at C‐37 position of GA by introducing of hydrophilic amines could lead to increased activity and improved drug‐like properties. These findings will enhance our understanding of the structure‐activity relationship (SAR) of GA and lead to the discovery of novel GA derivatives as potential anti‐tumor agents.     

Synthesis and Anti‐tumor Evaluation of B‐ring Modified Caged Xanthone Analogues of Gambogic Acid

Gambogic acid (GA, 1 ), the most prominent member of Garcinia natural products, has been reported to be a promising anti‐tumor agent. Previous studies have suggested that the planar B ring and the unique 4‐oxa‐tricyclo[4.3.1.0^3,7]dec‐2‐one caged motif were essential for anti‐tumor activity. To further explore the structure‐activity relationship (SAR) of caged Garcinia xanthones, two new series of B‐ring modified caged GA analogues 13a – 13e and 15a – 15e were synthesized utilizing a Claisen/Diel‐Alder cascade reaction. Subsequently, these compounds were evaluated for their in vitro anti‐tumor activities against A549, MCF‐7, SMMC‐7721 and BGC‐823 cancer cell lines by MTT assay. Among them, 13b – 13e exhibited micromolar inhibition against several cancer cell lines, being approximately 2–4 fold less potent in comparison to GA. SAR analysis revealed that the peripheral gem‐dimethyl groups are essential for maintaining anti‐tumor activity and substituent group on C1 position of B‐ring has a significant effect on potency, while modifications at C‐2, C‐3 and C‐4 positions are relatively tolerated. These findings will enhance our understanding of the SAR of Garcinia xanthones and lead to the development of simplified analogues as potential anti‐tumor agents.     

The influence of electron donor and electron acceptor groups on the electronic structure of the anti‐inflammatory tripeptide Cys‐Asn‐Ser

It has been discussed in the literature that electron delocalization along the peptide backbone and side chain modulates the physical and chemical features of peptides and proteins. The structure and properties of peptides are determined by their charge‐density distribution, such that the modification of its side chain plays an important role on its electronic structure and physicochemical properties. Research on Entamoeba histolytica soluble factors led to the identification of the pentapeptide Met‐Gln‐Cys‐Asn‐Ser, with anti‐inflammatory in vivo and in vitro effects. A synthetic pentapeptide, Met‐Pro‐Cys‐Asn‐Ser, maintained the same anti‐inflammatory actions in experimental assays. A previous theoretical study allowed proposing the Cys‐Asn‐Ser tripeptide (CNS tripeptide) as the pharmacophore group of both molecules. This theoretical hypothesis was recently confirmed experimentally. The objective of this work was to study the influence of the electron donor and electron withdrawing substituent groups on the electronic structure and physicochemical properties of the CNS tripeptide derivatives through a theoretical study at the density functional theory level of theory. Our results in deprotonation energies showed that the relative acidity of hydrogen atom (H2) of the serine‐amide group increases with the electron withdrawing groups. This result was confirmed by means of a study of bond order. The proton affinities illustrated that the electron donor groups favored the basicity of the amino group of the cysteine amino acid. Atomic charges, Frontier molecular orbitals (HOMO–LUMO), and electrostatic potential isosurface and its geometric parameters permitted to analyze the effect that provoked the electron donor and electron attractor groups on its electronic structure and physicochemical features and to identify some reactive sites that could be associated with the anti‐inflammatory activity of tripeptide CNS derivatives. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem 110:2398–2410, 2010     

Design,Synthesis, Configuration Research,and In Vitro Antituberculosis Activities of two Chiral Naphthylamine Substituted Analogs of Bedaquiline

Two chiral naphthylamine‐substituted analogs of Bedaquiline were selected from a series of compounds designed as anti‐tuberculosis drugs based on the structure activity relationship of bedaquiline for synthetic and stereochemical research. The compounds were synthesized from the chiral precursors for the first time, and their absolute configurations were determined by electronic circular dichroism and quantum chemical calculations. Conformational analyses were performed on the compounds to find the stable conformers and get better predicted results. In addition, the in vitro antituberculosis activities of the two compounds were investigated.     

Al2O3 Nanosheets Rich in Pentacoordinate Al3+ Ions Stabilize Pt‐Sn Clusters for Propane Dehydrogenation

In heterogeneous catalysis, supports play a crucial role in modulating the geometric and electronic structure of the active metal phase for optimizing the catalytic performance. A γ‐Al₂O₃ nanosheet that contains 27 % pentacoordinate Al³⁺ sites can nicely disperse and stabilize raft‐like Pt‐Sn clusters as a result of strong interactions between metal and support. Consequently, there are strong electronic interactions between the Pt and Sn atoms, resulting in an increase in the electron density of the Pt sites. When used in the propane dehydrogenation reaction, this catalyst displayed an excellent specific activity for propylene formation with >99 % selectivity, and superior anti‐coking and anti‐sintering properties. Its exceptional ability to maintain the high activity and stability at ultrahigh space velocities further showed that the sheet construction of the catalyst facilitated the kinetic transfer process.     

中药多糖成分前处理及检测方法研究进展

多糖是中药的重要活性成分之一,具有降血脂、降血糖、增强免疫、抗肿瘤、抗氧化、抗凝血、抗炎症、抗衰老等活性。该类物质具有极性强、分子量大、结构难确证等特点,成为中药多糖新药开发的瓶颈。该文综述了近10年关于中药多糖成分的前处理及检测方法,以期为中药多糖定性定量分析,质量控制的提高,多糖药物深度开发和中药物质基础的全面研究提供参考。     

Synthesis,Structural Characterization and Preliminary Biological Studies of Several Heterocyclic Transition Metal Carbonyl Complexes

The reaction of molybdenum, tungsten and manganese carbonyls with several thiazole heterocycle ligands yielded a number of coordinated transition metal complexes 1 – 10 . Of these complexes 1 – 6 are new compounds which have not been reported to date. The structures of new compounds were characterized by FT‐IR and ¹H‐NMR spectroscopy as well as single‐crystal X‐ray diffraction analysis. Complexes 1 – 10 are carbon monoxide releasing molecules that show structure‐related anti‐cancer activity. The cytotoxicity of all compounds on Hela cells was evaluated by MTT assay, and the results show that carbon monoxide releasing molecules containing such Schiff base ligands may have biomedical applications for their anti‐tumor effect.     

Anti‐inflammatory activities and glycerophospholipids metabolism in KLA‐stimulated RAW 264.7 macrophage cells by diarylheptanoids from the rhizomes of Alpinia officinarum

Alpinia officinarum is used for its anti‐inflammatory activity historically in China. Diarylheptanoids isolated from A. officinarum play important biological roles in the prevention and treatment of inflammatory disorders. Seven diarylheptanoids (1–7) were isolated from A. officinarum. The cell viabilities and anti‐inflammatory activities of diarylheptanoids were evaluated by MTT assay and tumor necrosis factor‐α production in Kdo2‐lipid A‐stimulated RAW 264.7 cells in vitro. The relationships between their anti‐inflammatories and structure‐activities are discussed. The results indicated that compounds 1 and 3–7 had significant anti‐inflammatory activities. The relationships between inflammation and phospholipids metabolism were elucidated by multivariate data analysis. Twenty‐two potential biomarkers were identified in inflammatory group vs. blank group, and 11 potential biomarkers were identified for inflammatory group vs. drug‐treatment groups. Ten common phospholipids were characterized. On the basis of a previous study in our laboratory, we found that phosphatidylethanolamine (18:0/18:1) might be the important glycerophospholipid biomarker in inflammation. In this study, we firstly combined anti‐inflammatory activities and glycerophospholipids changes of traditional Chinese medicine. This work suggests that the anti‐inflammatory activities of diarylheptanoids might be significantly related to glycerophospholipids and could provide a useful database for investigating the anti‐inflammatory effects of traditional Chinese medicine.     

1,3‐Dipolar cycloaddition reaction: Synthesis of novel 5,6‐dehydronorcantharidin derivatives of substituted aromatic amines with potential antitumor activities

Twelve novel compounds were synthesized by the [3+2] 1,3‐dipolar cycloaddition reaction of 5,6‐dehydronorcantharidin derivatives of substituted aromatic amines with nitrile oxides. The structure and the configuration of all compounds were confirmed by ¹H NMR, IR, MS, ¹H‐¹HCOSY, and NOESY spectral data. Their anti‐tumor activities are under way.