C5a受体拮抗剂W-54011的合成

以7-甲氧基-1-萘满酮为原料,经Wittig反应、去甲基化、烯醇互变和Jones氧化反应等制得关键中间体7-甲氧基-1,2,3,4-四氢化萘-1-羧酸(4); 4-异丙基苯胺和4-(二甲基胺基)苯甲醛经过还原胺化反应得(E)-4-{[(4-异丙基苯基)亚胺基]甲基}-N,N-二甲基苯胺(6); 4转化为相应的酰氯后与6反应合成N-[4-(二甲基氨基)苄基]-N-(4-异丙基苯基)-7-甲氧基-1,2,3,4-四氢化萘-1-甲酰胺(W-54011),总收率24%,其结构经¹H NMR, ¹³C NMR和HR-MS（ESI）表征。      

Synthesis and Characteristics of a New Molybdoantimonate KSbMoO_5

1 INTRODUCTION Great efforts have been made for the discovery of microporous solids due to their rich structural chemi- stry and wide applications in some commercial pur- poses as ion exchanger, absorbent, and catalyst[1]. Since many properties of porous materials depend on their composition and architecture, recent attention has been paid to incorporating other main group and tra- nsition metals into open frameworks, and plenty of materials are reported to contain polyhedra, such as [X…     

5-epi-Deoxyrhamnojirimycin is a potent inhibitor of an α-l-rhamnosidase: 5-epi-deoxymannojirimycin is not a potent inhibitor of an α-d-mannosidase

Whereas deoxyrhamnojirimycin (LRJ) 1 shows no significant inhibition of naringinase (an α-l-rhamnosidase), its C-5 epimer 2 is a potent and specific inhibitor of the enzyme and demonstrates the value of unambiguous chemical synthesis of such materials in the evaluation of their biological properties. In contrast, moderately weak inhibition towards an α-d-mannosidase is shown by both deoxymannojirimycin (DMJ) 5 and its C-5 epimer 6. Mimics of l-rhamnose which are recognised by enzymes that synthesise or process l-rhamnose may inhibit either the biosynthesis of the sugar or its incorporation into mycobacterial cell walls, providing new strategies for the treatment of diseases such as tuberculosis and leprosy. Molecular modelling studies provide a rationale for the surprisingly potent activity of the C-5 epimer 2 compared with LRJ 1 and support a general hypothesis that potent piperidine glycosidase inhibitors mimic the ⁴H₃ conformation of the relevant glycopyranosyl cation intermediate.     

Reaction of 2-hydroxyethylhydrazine with a trifluoromethyl-β-diketone: Study and structural characterization of a new 5-hydroxy-5-trifluoromethyl-4,5-dihydropyrazole intermediate

The reaction of the β-diketone 4,4,4-trifluoro-1-pyridin-2-yl-butane-1,3-dione and the monosubstituted hydrazine 2-hydroxyethylhydrazine has been investigated. Two products have been identified, 2-(2-hydroxyethyl)-3-pyridin-2-yl-5-trifluoromethyl-4,5-dihydropyrazole (P) and 2-(3-pyridin-2-yl-5-trifluoromethylpyrazol-1-yl)ethanol (L) in proportion 2:8, when the reaction was done at room temperature in ethanol for 15 h. The preparation of P as a pure product was performed in ethanol at 0 °C for 7 h. P has been characterized by ¹H, ¹³C{¹H} and ¹⁹F{¹H} NMR spectroscopy and by other techniques as appropriate.     

5-苄氧亚氨基-5-脱氧阿维菌素B1a的合成

以阿维菌素B1a为原料经过选择性氧化合成5-氧代-5-脱氧阿维菌素B1a, 再与O-取代羟胺盐酸盐反应合成了5个5-苄氧亚氨基-5-脱氧阿维菌素B1a (4a～4e), 通过¹H NMR, ¹³C NMR, MS, IR确证了它们的结构. 生测结果表明它们对于棉铃虫和甜菜夜蛾有一定的杀虫活性.     

Photoluminescence of a 5CB liquid crystal–organomontmorillonite nanoparticle heterocomposite

Photoluminescence (PL) of a heterocomposite, consisting of the nematic liquid crystal (LC) 4-pentyl-4´-cyanobiphenyl (5CB) and anisometric nanoparticles of montmorillonite (MMT) clay, modified by cetyltrimethylammonium bromide (CTAB) has been investigated at 4.2 and 300 K. The incorporation of this organoclay (B4) to 5CB decreases the emission intensity by 7–8 times due to efficient resonant quenching of the exciting energy by the organoclay. The spectrum shifts to a long-wave region, with this effect being considerably larger at low temperatures. Graphical separation of complex bands, corresponding to the bulk 5CB and 5СВ?+?В4 heterosystem at both temperatures revealed that the presence of the organoclay resulted in a significant growth of LC dimer quantity, shifting spectra towards longer wavelengths. Changes in the 5CB luminescence under organoclay influence can be explained by quite strong interphase interactions specified earlier by infrared spectroscopy between the MMT surface and LC, and by a realisation of more flat conformations of 5CB molecules. Confinement effects prevent full crystallisation of 5CB in the 5CB?+?B4 composite, and LC dimer structures located in the organoclay near-surface layers on the outer surface of the nanoparticles and inside its galleries remain in a larger amount, at low temperature, when compared to bulk 5CB. The remaining LC crystallises and photoluminescence from the 5CB monomers becomes intense.     

5-阿维菌素B1a酯的合成及生物活性

阿维菌素B_1a(AVB_1a)与羧酸在DMAP/DCC体系中直接酯化,得到10个5-AVB_1a酯衍生物,产率50%～79%;其化学结构由IR,¹H NMR,¹³CNMR和MS谱确证.生物活性测定结果表明,部分5-阿维菌素B_1a酯衍生物具有良好的杀虫、杀螨活性.     

Chlorine-induced assembly of a cationic coordination cage with a μ5-carbonato-bridged Mn(II)24 core

Chlorine caged in! The chlorine-induced assembly of six shuttlecock-like tetranuclear Mn(II) building blocks generated in situ based on p-tert-butylthiacalix[4]arene and facial anions gave rise to a novel truncated distorted octahedral cationic coordination cage with a μ(5)-carbonato-bridged Mn(II)(24) core.     

Why Do Five Ga+ Cations Form a Ligand‐Stabilized [Ga5]5+ Pentagon and How Does a 5:1 Salt Pack in the Solid State?

The reaction of the Ga⁺ source [Ga(PhF)₂]⁺[Al(OR^F)₄]^? with the neutral σ‐donor ligand dmap (4‐Me₂N‐C₆H₄N) produces the unexpectedly large and fivefold positively charged cluster cation salt [Ga₅(dmap)₁₀]⁵⁺([Al(OR^F)₄]^?)₅. It includes a regular and planar Ga₅ pentagon with strong metal–metal bonding. Additionally, the compound represents the first salt in which an ionic 1:5 packing is realized. We discuss the nature of this structure which results from the conversion of the non‐bonding 4s² lone‐pair orbitals into fully Ga‐Ga‐bonding orbitals and the solid‐state arrangement of the ions constituting the lattice as an almost orthohexagonal AX₅ lattice, possibly the aristotype of any 5:1 salt.     

syn,Anti isomerization of 5,5′-Bis-5H-dibenzo[a,d]cyclohepten-5-ylidene

syn-5,5-Bis-5H-dibenzo[a,d]cyclohepten-5-ylidene (2syn), an overcrowded bistricyclic aromatic ene with central seven-membered rings, undergoes a thermal isomerization to the anti stereoisomer (2anti) at elevated temperatures, with G _inv (174°C)=36.4 kcal/mole. The high-energy barrier for syn anti isomerization of2 is compared with the corresponding inversion barrier of 5H-dibenzo[a,d]cycloheptene derivatives and interpreted in terms of a lower degree of overcrowding in2 relative to bistricyclic enes (1) with central five- and six-membered rings. The overcrowding features of2syn,2anti, and theiranti-10,11,10,11-tetrahydro derivative (3) is analyzed, and a mechanism for the syn anti isomerization of 2 is proposed.     

Preparation and Structural Characterization of a Heterobimetallic Sulfide Cluster Compound [(η 5-C5Me5)WS3Au(dppms)]

A novel heterobimetallic sulfide cluster [( ⁵-C₅Me₅)WS₃Au(dppms)][dppms = bis(diphenylphosphino)methane monosulfide] was prepared by the reaction of [PPh₄][( ⁵-C₅Me₅)WS₃] with AuI and dppm [dppm = bis(diphenylphosphino)methane] in MeCN. The title compound was fully characterized by elemental analysis, i.r., u.v.–vis., ¹H-n.m.r. spectra, and by single crystal X-ray crystallography. In the molecular structure, the Au atom is trigonally coordinated by two bridging S atoms of a [( ⁵-C₅Me₅)WS₃]^– anion and a P atom of the dppms molecule. The formation mechanism for this compound is discussed.     

Syntheses and Bioactivity of 4＂-Sulfonate-5-triphenyl silyl Avermectin B1a and Ivermectin B1a Derivatives

Fourteen new derivatives of avermectin B1a, and ivermectin B1a were synthesized from C5-O-triphenyl silylavermectin B1a and ivermectin B1a (yield from 40% to 83%). Their chemical structures were characterized by means of IR. ^1H NMR, ^13C NMR and FAB-MS spectrometries. Some of them show excellent insecticidal activity.     

Characterization of a core fragment of the rhesus monkey TRIM5α protein

Background  

Like all tripartite motif (TRIM) proteins, the retroviral restriction factor TRIM5α consists of RING, B-box 2 and coiled-coil domains, with a C-terminal B30.2(SPRY) domain. Although structures have been determined for some individual TRIM domains, the structure of an intact TRIM protein is unknown.     

Synthesis of Spirobenzopyrans Carrying a Monoaza-benzo-15-C-5 at the 8-position

SpirobenzopyranderivativesarewellknownphotochroAncorganiccompounds,whichcanbereversiblyisomerizedbyUVandvisiblelightirradiation.Whencrownmoietiesareincorporatedtothespirobenzopyrans,theymayprovidespirobenzopyranderivativeswithspecificcationbindingabilities,whichcaninduceisomerizationofthespirobenzopyrans,thusdrasticallyaffectingtheisomerizationequilibriumbetweenthespiropyranandthemerocycanineforms.Thesecrownedspirobenzopyranderivativesaremoreeffectiveforphotochemicalcontrolofphysicalpropertie…     

5β(H)-Austricin, a New Guaianolide from Artemisia leucodes

A new sesquiterpene lactone 5(H)-austricin was isolated from white wormwood (Artemisia leucodes Schrenk.). Its structure was established by chemical and spectral methods.     

A new tetrasubstituted α-fluoro cyclohexanone bearing a fluoroisopropyl group at C5

A new tetrasubstituted cyclohexanone 5 fluorinated at C2 and having a fluoroisopropyl group at C5 has been synthesized in five steps from 3-methyl cyclohexenone and the structure of both diastereomers fully assigned. It is shown that diastereomer Ia having the fluorine atom at C2 in the axial position (in the most populated conformer of this diastereomer) is major and is a good catalyst for epoxidation of trans-olefins by oxone while diastereomer IIe is not. Moreover, only 0.3 equiv. of 5-Ia are necessary and the ketone is totaly recovered after reaction (no Baeyer-Villiger).     

Oligomers of a 5-carboxy-methanopyrrolidine β-amino acid. A search for order

CD spectra for homooligomers (n = 4, 6, 8) of (1S,4R,5R)-5-syn-carboxy-2-azabicyclo[2.1.1]hexane (MPCA), a methano-bridged pyrrolidine β-carboxylic acid, suggest an ordered secondary structure. Even in the absence of internal hydrogen bonding, solution NMR, X-ray, and in silico analyses of the tetramer are indicative of conformations with trans-amides and C(5)-amide-carbonyls oriented toward the C(4) bridgehead. This highly constrained β-amino acid could prove useful in the ongoing development of well-defined foldamers.     

Development of a New Clean-up Method for the Determination of 5-methyl-tetrahydrofolate in Milk Samples Using a Sol-Gel β-Lactoglobulin Column

The specific forms of folic acid, a vitamin of the B-group, are generally determined in foods after sample clean-up using affinity columns containing folate binding protein covalently bound to a solid support material. The new approach described in the present paper is to isolate the target analyte by using the less costly milk protein β-lactoglobulin, entrapped in the pores of a sol-gel glass. Sol-gel β-lactoglobulin columns were included in a clean-up procedure developed to determine 5-methyl-tetrahydrofolate in milk samples. Concentrations of 5-methyl-tetrahydrofolate in milk samples with different fat contents ranged from 31 to 70 ng/ml. Repeated use of the β-lactoglobulin columns for sample preparation resulted in a decrease of analyte recovery. However, due to the high column to column reproducibility good results were obtained when the standard addition method was performed with columns which had already been used for the same number of sample clean-ups.