Iron oxide pillared graphite

We show that alpha-Fe2O3- and Fe3O4-pillared graphites can be prepared by pillaring graphite oxide with trinuclear iron acetato complex ion and calcining it in air and in vacuo, respectively. A pillared graphite structure is confirmed by transmission electron microscopy observations. The adsorption isotherms of water indicate that the mesopores of Fe3O4-pillared graphite constitute a hydrophobic nanospace.     

A New Synthesis of Some Non-Steroidal Anti-Inflammatory Agents via Cyanophosphates1)

A simple and convenient procedure for the syntheses of some nonsteroidal anti-inflammatory agents, ibuprofen, rac-naproxen, clidanac and loxoprofen, is described.     

Anion-exchange separation of rhodium and iridium by ECTEOLA-cellulose column

Summary The separation of Rh(III) and Ir(IV) in amounts of 20–5300 and 20–7700 g, respectively, and in ratios of RhIr=1100 to 1001 was achieved without cross-contamination by use of a 3 g ECTEOLA-cellulose column. Rh was first eluted with 40 ml of a 3 mol/l HCl-1% (w/v) NaClO₃ solution. Ir(IV) was desorbed with 60 ml of a 6 mol/l HCl-0.1% (w/v) NaClO₃ solution. Quantitative recoveries were obtained for each metal. The present method provides much better resolution than the other existing anion-exchange methods and can effectively be applied to the separations and recoveries of Rh and Ir(III or IV) present in a more extensive range of amounts and ratios.

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Anionenaustausch-Trennung von Rhodium und Iridium mit Hilfe einer ECTEOLA-Cellulose-Säule

     

Coherent oscillations in ultrafast fluorescence of photoactive yellow protein

The ultrafast photoinduced dynamics of photoactive yellow protein in aqueous solution were studied at room temperature by femtosecond fluorescence spectroscopy using an optical Kerr-gate technique. Coherent oscillations of the wave packet were directly observed in the two-dimensional time-energy map of ultrafast fluorescence with 180 fs time resolution and 5 nm spectral resolution. The two-dimensional map revealed that four or more oscillatory components exist within the broad bandwidth of the fluorescence spectrum, each of which is restricted in the respective narrow spectral region. Typical frequencies of the oscillatory modes are 50 and 120 cm(-1). In the landscape on the map, the oscillatory components were recognized as the ridges which were winding and descending with time. The amplitude of the oscillatory and winding behaviors is a few hundred cm(-1), which is the same order as the frequencies of the oscillations. The mean spectral positions of the oscillatory components in the two-dimensional map are well explained by considering the vibrational energies of intramolecular modes in the electronic ground state of the chromophore. The entire view of the wave packet oscillations and broadening in the electronic excited state, accompanied by fluorescence transitions to the vibrational sublevels belonging to the electronic ground state, was obtained.     

Strong binding between acidic guests and fluorescein modified -γ-Cyclodextrin via hydrogen bonding

-Cyclodextrin with appended fluorescein (1) has been prepared as a sensor and a charge-changeable receptor for detecting organic compounds including terpenoids, carboxylic acids and bile acids. Compound1 has cationic, neutral and anionic forms depending on the pH of the solutions. The anionic form of1 at about neutral pH exhibits the highest sensing ability for carboxylic acids and bile acids, while at alkaline pH it detects hardly any of the guests examined. The high sensitivity and selectivity of the anionic form of1 at around neutral pH for acidic guests seems to be caused by the hydrogen bond between the phenoxide anion moiety of fluorescein and acidic guests. The neutral form of1 exhibits little sensing ability for all the guests, but the cationic form shows comparatively higher sensing ability for the guests examined.     

Catalytic asymmetric mannich-type reactions activated by ZnF2 chiral diamine in aqueous media

Catalytic asymmetric Mannich-type reactions of an alpha-hydrazono ester with silicon enolates in aqueous media have been developed by using ZnF2 and chiral diamines as catalysts. In these reactions, both Zn2+ and a fluoride anion were necessary to achieve high yields and enantioselectivities, suggesting a double activation mechanism, in which Zn2+ activates the alpha-hydrazono ester and the fluoride anion simultaneously activates the silicon enolate. When chiral diamine ligands bearing methoxy-substituted aromatic rings were employed, the reactions in aqueous THF were markedly accelerated. Furthermore, the use of these diamines facilitated the asymmetric Mannich-type reactions in water without any organic cosolvents. It is noteworthy that either syn or anti adducts were stereospecifically obtained from (E)- or (Z)-silicon enolates, respectively. Interestingly, these reactions proceeded smoothly only in the presence of water. On the basis of several experimental results, it can be concluded that the reaction mechanism is likely to be a fluoride-catalyzed one, in which the ZnF2 chiral diamine complex is regenerated from the Me3SiF formed during the reaction.     

Asteropine A, a sialidase-inhibiting conotoxin-like peptide from the marine sponge Asteropus simplex

Marine sponges contain structurally intriguing and biologically active peptides of nonribosomal peptide synthase origin, often containing amino acids with novel structures. Here we report the discovery of asteropine A (APA), a cystine knot to be isolated from marine sponges. The solution structure of APA as determined by NMR belongs to the four-loop class of cystine knots similar to those of some conotoxins and spider toxins. However, the highly negatively charged surface of APA is uncommon among other cystine knots. APA competitively inhibits bacterial sialidases, but not a viral sialidase. APA was inactive against all other enzymes tested and did not have any apparent antitumor activity. Our data suggest that APA and other knotting peptides may be important leads for antibacterial and even antiviral drug development.     

Anacyclus pyrethrum (L): Chemical Composition,Analgesic, Anti-Inflammatory,and Wound Healing Properties

Background: Anacyclus pyrethrum (A. pyrethrum) is a wild species belonging to the family Asteraceae, which is used in traditional medicines. Aim of the study: This work was undertaken to study the chemical composition, analgesic, anti-inflammatory, and wound healing properties of hydroalcoholic extracts of different parts (roots, seeds, leaves, and capitula) of A. pyrethrum. Material and Methods: The phytochemical analysis of the studied extracts was conducted by GC-MS. The analgesic activity was evaluated in mice using acetic acid and formaldehyde methods. The anti-inflammatory activity was tested using the inhibitory method of edema induced in rats. The healing activity of the hydroethanolic extracts was explored by excision and incision wound healing models in rats. Results: The phytochemical analysis of the studied plant extracts affirmed the presence of interesting compounds, including some newly detected elements, such as sarcosine, N-(trifluoroacetyl)-butyl ester, levulinic acid, malonic acid, palmitic acid, morphinan-6-One, 4,5.alpha.-epoxy-3-hydroxy-17-methyl, 2,4-undecadiene-8,10-diyne-N-tyramide, and isovaleric acid. The extracts of different parts (roots, seeds, leaves, and capitula) exhibited promising anti-inflammatory, analgesic, and wound healing effects, with percentages of inhibition up to 98%, 94%, and 100%, respectively. Conclusion: This study might contribute towards the well-being of society as it provides evidence on the potential analgesic, anti-inflammatory, and wound healing properties of A. pyrethrum.