Ionic Liquid Promoted One-Pot Synthesis of Furo[2,3-<Emphasis Type="Italic">d</Emphasis>]pyrimidine-2,4(1<Emphasis Type="Italic">H</Emphasis>,3<Emphasis Type="Italic">H</Emphasis>)-diones

Summary. The three-component condensation of aldehyde, N,N′-dimethylbarbituric acid and alkyl or aryl isocyanide afforded the corresponding furo[2,3-d]pyrimidine-2,4(1H,3H)-diones in 1-butyl-3-methylimidazolium bromide as an ionic liquid in high yields at room temperature within several minutes.     

<Emphasis Type="Italic">Raman</Emphasis> Spectroscopy and <Emphasis Type="Italic">Ab-Initio</Emphasis> Model Calculations on Ionic Liquids

Summary. A review of the recent developments in the study and understanding of room temperature ionic liquids are given. An intimate picture of how and why these liquids are not crystals at ambient conditions is attempted, based on evidence from crystallographical results combined with vibrational spectroscopy and ab-initio molecular orbital calculations. A discussion is given, based mainly on some recent FT-Raman spectroscopic results on the model ionic liquid system of 1-butyl-3-methylimidazolium ([C₄ mim][X]) salts. The rotational isomerism of the [C₄ mim]⁺ cation is described: the presence of anti and gauche conformers that has been elucidated in remarkable papers by Hamaguchi et al. Such presence of a conformational equilibrium seems to be a general feature of the room temperature liquids. Then the “localized structure features” that apparently exist in ionic liquids are described. It is hoped that the structural resolving power of Raman spectroscopy will be appreciated by the reader. It is of remarkable use on crystals of known different conformations and on the corresponding liquids, especially in combination with modern quantum mechanics calculations. It is hoped that these interdisciplinary methods will be applied to many more systems in the future. A few examples will be discussed.     

Efficient <Emphasis Type="Italic">Baylis-Hillman</Emphasis> Reaction <Emphasis Type="Italic">via</Emphasis> a 1,4-Diazabicyclo[2.2.2]octane-based Ionic Catalyst

Summary. A novel ionic catalyst, 1-butyl-4-aza-1-azoniabicyclo[2.2.2]octane chloride based on 1,4-diazabicyclo[2.2.2]octane was synthesized and applied in the Baylis-Hillman reaction, which occurred readily at room temperature to afford the corresponding adducts in good yield. The ionic catalyst could be recycled for seven runs without diminution in its catalytic activity.     

Mercaptan addition to 1-<Emphasis Type="Italic">O</Emphasis>-allyl-2,3,4,6-tetra-<Emphasis Type="Italic">O</Emphasis>-acetyl-<Emphasis Type="Italic">β</Emphasis>-D-galactopyranose

Addition of ethyl-, propyl-, and n-butylmercaptans to 1-O-allyl-2,3,4,6-tetra-O-acetyl-β-D-galactopyranose in the presence of benzoyl peroxide catalyst was studied for the first time. The products were 1-O-(3-ethylthiopropyl)-2,3,4,6-tetra-O-acetyl-β-D-galactopyranose, 1-O-(3-propylthiopropyl)-2,3,4,6-tetra-O-acetyl-β-D-galactopyranose, and 1-O-(3-butylthiopropyl)-2,3,4,6-tetra-O-acetyl-β-D-galactopyranose. Deacetylation of 1-O-(3-ethylthiopropyl)-2,3,4,6-tetra-O-acetyl-β-D-galactopyranose produced 1-O-(3-ethylthiopropyl)-β-D-galactopyranose. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 209–211, May–June, 2007.     

Activation energy (Δ<Emphasis Type="Italic">G</Emphasis>*), enthalpy (Δ<Emphasis Type="Italic">H</Emphasis>*), and entropy (Δ<Emphasis Type="Italic">S</Emphasis>*) of some indoles and certain of their binary mixtures

Thermodynamic parameters, like, change of activation energy for dipole orientation (ΔG*), enthalpy (ΔH*), and entropy (ΔS*) of activation in the case of binary-, ternary-, etc. mixtures of polar molecules in pure liquid phase or in dilute solution phase in a non polar solvent helps in drawing certain quantitative conclusions regarding their relaxation behavior as to whether a single component is responsible for observed microwave absorption or a cooperative phenomenon (average) by all the dipoles of the mixture contribute to it. Dielectric relaxation behavior of polar molecules in a non-polar solvent, or mixtures of these substances at different microwave frequencies and over a range of temperatures and concentrations give a method of determining these quantities. Such an experimental investigation on verity of systems is necessary to draw quantitative conclusions regarding the system of the molecules which are not studied so as to examine if the results obtained are in favor or against the general conclusions already arrived at, in other systems. With this in view, systematic dielectric measurements in a range of temperatures are carried out at a single microwave frequency on a single weight fraction in benzene of the four substituted indoles, namely, 5-Bromoindole, 5-Fluoroindole, 2,3-Dimethylindole, 2,5-Dimethylindole and on binary (1:1) mixtures of 2,5-Dimethylindole + 5-Bromoindole and 2,3-Dimethylindole + 5-Fluoroindole in benzene as solvent at different temperatures. The results are presented and discussed.     

Emulsion Polymerization of Styrene in the Presence of <Emphasis Type="Italic">C</Emphasis>-Phenyl-<Emphasis Type="Italic">N-tert</Emphasis>-Butylnitrone

The radical polymerization of styrene in an emulsion stabilized with an ionic surfactant, with C-phenyl-N-tert-butylnitrone as chain-terminating agent and ammonium persulfate as initiator, was studied.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 5, 2005, pp. 831–835.Original Russian Text Copyright © 2005 by Grishin, Lazarev, Semenycheva, Nikolaev.     

Kinetic characterisation of arylamine <Emphasis Type="Italic">N</Emphasis>-acetyltransferase from <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis>

Background  

Arylamine N-acetyltransferases (NATs) are important drug- and carcinogen-metabolising enzymes that catalyse the transfer of an acetyl group from a donor, such as acetyl coenzyme A, to an aromatic or heterocyclic amine, hydrazine, hydrazide or N-hydroxylamine acceptor substrate. NATs are found in eukaryotes and prokaryotes, and they may also have an endogenous function in addition to drug metabolism. For example, NAT from Mycobacterium tuberculosis has been proposed to have a role in cell wall lipid biosynthesis, and is therefore of interest as a potential drug target. To date there have been no studies investigating the kinetic mechanism of a bacterial NAT enzyme.     

<Emphasis Type="Italic">Brønsted</Emphasis> Acids in Ionic Liquids: Fundamentals,Organic Reactions,and Comparisons

Summary. A background for studying acids in various solvents is developed, emphasizing the importance of knowing to what extent a solvent conducts electricity and is therefore ionized, the dissociation equilibria of common molecular solvents and the acidic and basic species generated by solvent leveling. Acidity measurements in the atypical solvent water are discussed and the common method of expressing acidity in other systems – by Hammett values – is introduced. Representative examples of reactions involving Br?nsted acids in ionic liquids are presented and attention paid to the questions of speciation and acidity values. It is found that the gas phase proton affinity of a base is often a better guide to the acidity of its conjugate acid in an ionic liquid than is the dissociation constant of the said acid in water.     

Biological Synthesis of Gold Nanoparticles by Fungus <Emphasis Type="Italic">Epicoccum</Emphasis><Emphasis Type="Italic">nigrum</Emphasis>

Gold nanoparticles exhibit unique optical, thermal, chemical and physical properties. The microorganisms have high potential for production of nanoparticles with wide applications. Application of fungi to produce nanoparticles is potentially exciting because of their ability to secrete large amounts of enzymes. In this study, we investigated biosynthesis of gold nanoparticles by the fungus Epicoccum nigrum isolated from Andalian gold mine in north-west of Iran. The gold nanoparticles were produced intra and extracellular by reaction of an aqueous solution of chloroauric acid with the biomass of fungus E. nigrum. The produced gold nanoparticles were in the size range of 5–50 nm in spherical and rod shapes. This is the first report on the biosynthesis of gold nanoparticles by the fungus E. nigrum.     

Glucomannans of <Emphasis Type="Italic">Serissa serissoides</Emphasis> stem

One β-D-glucomannan was isolated from Serissa serissoides (DC.) Druce. The average molecular weight of the polysaccharide was established to be 2.9 × 10³ Da. The structure of the polysaccharide from S. serissoides (SSP) was investigated by using sugar and methylation analysis, infrared spectroscopy, mass spectrometry, and NMR spectroscopy. The experiments revealed that SSP consisted of β-D-Glcp and β-D-Manp units in the ratio of approximately 1.1:1 with β-D-(1→4)-Glcp and β-D-(1→2) Manp linkages.     

Reductive Acylamination of Pyridine <Emphasis Type="Italic">N</Emphasis>-Oxide with Aminopyridines and Their <Emphasis Type="Italic">N</Emphasis>-<Emphasis Type="Italic">p</Emphasis>-Tolylsulfonyl Derivatives

Pyridine N-oxide reacts with 2- and 3-aminopyridines and their N-p-tolylsulfonyl derivatives in alkaline medium in the presence of p-toluenesulfonyl chloride to give N-p-tolylsulfonyl-2,2′- and 2,3′-dipyridylamines, respectively, as a result of reductive acylamination. In the reactions with 4-aminopyridine and 4-p-tolylsulfonyl-aminopyridine, their N-p-tolylsulfonyl- and N,N-bis(p-tolylsulfonyl) derivatives are formed, while reductive acylamination does not occur.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 1, 2005, pp. 128–130.Original Russian Text Copyright © 2005 by Solekhova, Kurbatov.     

Aryltetralin Lignans from <Emphasis Type="Italic">Linum mucronatum</Emphasis> Bertol. ssp. <Emphasis Type="Italic">mucronatum</Emphasis>

The dried and aerial part of Linum mucronatum ssp. mucronatum was analyzed by gas chromatography-mass spectrometry (GC-MS). Two aryltetralin lignans, podophylloyoxin, 6-methoxypodophylloyoxin, and β-peltatin, were identified. This is the first report of the analysis of L. mucronatum ssp. mucronatum.__________Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 24–25, January–February, 2005.     

<Emphasis Type="Italic">DegP</Emphasis> and Related Genes as Stress-Markers for <Emphasis Type="Italic">E.Coli</Emphasis>-Viability – Ultra-Sensitive RT-Real-Time PCR

Summary. The study was done to set up an on-line viability test system based on the stress-response of pathogenic E.coli. Fully automated and computerized pathogen detection was achieved via RNA expression monitoring using an high-speed real-time PCR-system with single molecule sensitivity. The device was developed in a collaboration of SAUR, France, the TU Delft (Kluyver Laboratorium – Analytical Biotechnology, Netherlands) and Attophotonics Bioscience, Austria.The automated viability assay is fully hands-off, using a continuous concentration process of the pathogens from litres sample down to tens of millilitres, cell cracking to DNA/RNA solution and further concentration down to a few hundred microlitres. RT-PCR and real-time-PCR are done with a robotic system. DegP found from E.coli to human was selectively induced within the device via heat shock at 50°C. Up to 1000 fold induction was achieved from environmental to heat-shock level. It was proven that degP quantification via RT-real-time PCR provides an excellent basis for multi-organism viability detection.Received September 16, 2002; accepted February 20, 2003 Published online September 15, 2003     

Cytotoxic phenolic glycosides from <Emphasis Type="Italic">Boschniakia himalaica</Emphasis>

A new lignan glycoside, 9-acetyl lanicepside B (1), was isolated from the whole plant of Boschniakia himalaica, along with five known compounds, lanicepside A (2), plantainoside D (3), plantamajoside (4), (–)-woonenoside XI (5), and syringin (6). The new compound's structure was established on the basis of detailed 1D and 2D NMR spectroscopic analysis and chemical evidence. 9-Acetyl lanicepside B (1) showed weak in vitro cytotoxic activities against A549 and P388 with IC₅₀ values of 64.7 μM and 72.5 μM, respectively. Syringin (6) showed moderate in vitro cytotoxic activities against A549 and HL-60 with IC₅₀ values of 32.5 μM and 41.8 μM, respectively.     

Synthesis of new 1<Emphasis Type="Italic">H</Emphasis>-pyridazine derivatives <Emphasis Type="Italic">peri</Emphasis>-annelated with acenaphthene and acenaphthylene

The reaction of 6-acetyl-5-hydroxyacenaphthene with methylhydrazine afforded 1,3-dimethyl-1H-6,7-dihydroacenaphtho[5,6-de]pyridazine. Its dehydrogenation with chloranil gave 1,3-dimethyl-1H-acenaphtho[5,6-de]pyridazine, which is a heteroaromatic compound with an essentially new topology of the ρsystem. The reaction of 3-methyl-1H-6,7-dihydroacenaphtho[5,6-de]pyridazine with 3,5-di-tert-butyl-1,2-benzoquinone yielded a dimer containing the acenaphthene and acenaphthylene moieties of peri-annelated 1H-1,2-diazines connected in positions 1′ and 9.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 777–780, March, 2005.     

Triterpene Glycosides from <Emphasis Type="Italic">Kalopanax septemlobum</Emphasis>. II. Glycosides E,K, and L from Leaves of <Emphasis Type="Italic">Kalopanax septemlobum</Emphasis> var. <Emphasis Type="Italic">maximowiczii</Emphasis> Introduced to Crimea

The known hederagenin 3-O-β-D-glucopyranosyl-(1→4)-O-β-D-xylopyranosyl-(1→ 3)-O-α-L-rhamnopyranosyl-(1→2)-O-α-L-arabinopyranoside (sapindoside C) and its 28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl and 28-O-α-L-rhamnopyranosyl-(1→4)-O-6-O-acetyl-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl esters, new triterpene glycosides, were isolated from leaves of Kalopanax septemlobum var. maximowiczii introduced to Crimea. The structures of these compounds were established using chemical methods and two-dimensional NMR spectroscopy.__________Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 260–262, May–June, 2005.     

Synthesis from geraniol of (2<Emphasis Type="Italic">E</Emphasis>,6<Emphasis Type="Italic">E</Emphasis>,10<Emphasis Type="Italic">E</Emphasis>,14<Emphasis Type="Italic">E</Emphasis>)-16-hydroxygeranylgeraniol and some of its derivatives

Several α,ω-bifunctional derivatives of E,E,E-geranylgeraniol were prepared via convergent synthesis starting with geraniol (8), which was converted in three steps into the tetrahydropyranyl ether of 8-chlorogeraniol (9) and 8-hydroxygeranylphenylsulfone (10). Combination of synthons 9 and 10 with subsequent reductive removal of the phenylsulfonyl group produced the tetrahydropyranyl ether of ω-hydroxygeranylgeraniol (5), hydrolysis of which gave exclusively trans-ω-hydroxygeranylgeraniol (1). Derivatives 5–7 of geranylgeraniol were synthesized using standard methods. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 231–234, May–June, 2007.     

Remote Oxygen and Nitrogen Plasma Inactivation of <Emphasis Type="Italic">Staphylococcus</Emphasis><Emphasis Type="Italic">aureus</Emphasis>: Effects and Mechanisms

The distribution of active species in remote oxygen and nitrogen plasma and the germicidal effect (GE) of Staphylococcus aureus on the surface of medical poly(tetrafluoroethylene), polyvinyl chloride and polyethylene terephthalate films, which had been widely used in medical devices, were studied. The results showed that the concentration of electrons and ions decreased rapidly with increasing the distance from the center of induction coil, which approximated to 0 at 40 cm, whereas the concentration of both oxygen and nitrogen radicals reduced slowly, which decreased 20% within 40 cm. Fast etching action on cell membrane by electrons, ions and radicals are primary reasons of oxygen and nitrogen plasma inactivation, which leads to the cellular contents effuse and engender bacteria death, however, the GE of UV radiation in remote plasma is feebleness comparatively. The GE also depends on the oxidation of gas for discharge and the surface characters of material.     

New Benzo[<Emphasis Type="Italic">b</Emphasis>]xanthones from Diels-Alder Reactions of Chromone-3-carboxaldehydes with <Emphasis Type="Italic">ortho</Emphasis>-Benzoquinodimethanes

Summary.  New benzo[b]xanthone derivatives, having substituents in the A and D rings, were prepared from cycloaddition reactions of chromone-3-carboxaldehydes with ortho-benzoquinodimethanes, generated in situ from 1,3-dihydrobenzo[c]thiophene 2,2-dioxide, followed by oxidation of the obtained diastereomeric adducts. The structure of all compounds was fully established by 1D and 2D NMR, MS, and elemental analysis. The stereochemistry of the obtained diastereomeric cycloadducts was established by NOESY experiments. Corresponding author. E-mail: arturs@dq.ua.pt Received September 16, 2002; accepted September 20, 2002