Intermolecular 1,3-dipolar cycloadditions of azomethine imines

Dipolar cycloadditions of azomethine imines, formed in situ from aldehydes and N1-alkyl-N2-acylhydrazines, with electron-deficient dipolarophiles produce pyrazolidines: mono-substituted dipolarophiles afford principally 4-substituted pyrazolidines

An alkylation route to carbo- and heteroaromatic amino acids

Amino acids carrying aromatic carbo- and heterocycles in the side chain, such as naphthyl-, biphenyl- and pyridylalanines, have been prepared by alkylation of a glycine enolate with a haloalkyl carbocycle or heterocycle, with enantiomeric excess up to 87% using the ephedrine amide protocol

A catalytic dipolar cycloaddition route to pyrroloimidazoles

A catalytic method involving carbenoid insertion onto dihydroimidazoles is reported for the generation of dihydroimidazolium ylides, and their subsequent diastereoselective cycloaddition to form pyrrolo[1,2-a]imidazole

Isolation of novel para-pentyl phenyl benzoate from Mondia whitei.(Hook.F.) skeels (periplocaceae), its structure, synthesis and neuropharmacological evaluation

Background: Mondia whitei L. (Hook. F.) Skeels (Periplocaceae) is a medicinal plant used locally in managing pain, fever, loss of appetite and as aphrodiasc in the South-Western states of Nigeria. However, the fruit is consumed habitually in the South-Eastern states of Nigeria, leading to speculation that it may possess some central nervous system effect but which has not been scientifically investigated, hence this study.Methodology: Fresh fruits of Mondia whitei were collected and identified by a taxonomist. They were chopped into small pieces and extracted with absolute ethanol. The crude extract was subjected to various chromatographic techniques to isolate a novel compound whose structure was elucidated from the analysis of the crystal data and by extensive use of spectroscopy. The structure was confirmed by synthesis. The compound was subjected to anxiolytic and sedative activity assay. Computational analysis of the receptor binding event of isolated compound at the gamma amino butyric acid A receptor was also evaluated.Results: The structure of the compound was elucidated as para pentyl phenyl benzoate. The neuropharmacological evaluation of the compound indicated significant (p<0.05) depression of the central nervous system. The binding characteristics of the compound to gamma amino butyric acid A receptors appears to be more favorable than those obtained for gamma amino butyric acid, chlorpromazine, benzamidine, and is comparable with the affinity obtained for pentobarbitone and diazepam.Conclusion: These present data provide evidence for the role of para pentyl phenyl benzoate in the habitual consumption of the fruit as well as its central nervous system activities.Keywords: Mondia whitei, Periplocaceae, isolation and synthesis, sedative and anxiolytic effect and Para pentylphenyl benzoat

Isolation of novel para-pentyl phenyl benzoate from Mondia whitei. (Hook.F) Skeels (Periplocaceae), its structure, synthesis, and neuropharamacological evaluation

Background: Mondia whitei L. (Hook. F.) Skeels (Periplocaceae) is a medicinal plant used locally in managing pain, fever, loss of appetite and as aphrodiasc in the South-Western states of Nigeria. However, the fruit is consumed habitually in the South-Eastern states of Nigeria, leading to speculation that it may possess some central nervous system effect but which has not been scientifically investigated, hence this study. Methodology: Fresh fruits of Mondia whitei were collected and identified by a taxonomist. They were chopped into small pieces and extracted with absolute ethanol. The crude extract was subjected to various chromatographic techniques to isolate a novel compound whose structure was elucidated from the analysis of the crystal data and by extensive use of spectroscopy. The structure was confirmed by synthesis. The compound was subjected to anxiolytic and sedative activity assay. Computational analysis of the receptor binding event of isolated compound at the gamma amino butyric acid A receptor was also evaluated. Results: The structure of the compound was elucidated as para pentyl phenyl benzoate. The neuropharmacological evaluation of the compound indicated significant (p<0.05) depression of the central nervous system. The binding characteristics of the compound to gamma amino butyric acid A receptors appears to be more favorable than those obtained for gamma amino butyric acid, chlorpromazine, benzamidine, and is comparable with the affinity obtained for pentobarbitone and diazepam. Conclusion These present data provide evidence for the role of para pentyl phenyl benzoate in the habitual consumption of the fruit as well as its central nervous system activities

ISOLATION OF NOVEL PARA-PENTYL PHENYL BENZOATE FROM MONDIA WHITEI.(HOOK.F.) SKEELS (PERIPLOCACEAE), ITS STRUCTURE, SYNTHESIS AND NEUROPHARMACOLOGICAL EVALUATION.

Background: Mondia whitei L. (Hook. F.) Skeels (Periplocaceae) is a medicinal plant used locally in managing pain, fever, loss of appetite and as aphrodiasc in the South-Western states of Nigeria. However, the fruit is consumed habitually in the South-Eastern states of Nigeria, leading to speculation that it may possess some central nervous system effect but which has not been scientifically investigated, hence this study. Methodology: Fresh fruits of Mondia whitei were collected and identified by a taxonomist. They were chopped into small pieces and extracted with absolute ethanol. The crude extract was subjected to various chromatographic techniques to isolate a novel compound whose structure was elucidated from the analysis of the crystal data and by extensive use of spectroscopy. The structure was confirmed by synthesis. The compound was subjected to anxiolytic and sedative activity assay. Computational analysis of the receptor binding event of isolated compound at the gamma amino butyric acid A receptor was also evaluated. Results: The structure of the compound was elucidated as para pentyl phenyl benzoate. The neuropharmacological evaluation of the compound indicated significant (

The Science of Sungrazers, Sunskirters, and Other Near-Sun Comets

This review addresses our current understanding of comets that venture close to the Sun, and are hence exposed to much more extreme conditions than comets that are typically studied from Earth. The extreme solar heating and plasma environments that these objects encounter change many aspects of their behaviour, thus yielding valuable information on both the comets themselves that complements other data we have on primitive solar system bodies, as well as on the near-solar environment which they traverse. We propose clear definitions for these comets: We use the term near-Sun comets to encompass all objects that pass sunward of the perihelion distance of planet Mercury (0.307 AU). Sunskirters are defined as objects that pass within 33 solar radii of the Sun’s centre, equal to half of Mercury’s perihelion distance, and the commonly-used phrase sungrazers to be objects that reach perihelion within 3.45 solar radii, i.e. the fluid Roche limit. Finally, comets with orbits that intersect the solar photosphere are termed sundivers. We summarize past studies of these objects, as well as the instruments and facilities used to study them, including space-based platforms that have led to a recent revolution in the quantity and quality of relevant observations. Relevant comet populations are described, including the Kreutz, Marsden, Kracht, and Meyer groups, near-Sun asteroids, and a brief discussion of their origins. The importance of light curves and the clues they provide on cometary composition are emphasized, together with what information has been gleaned about nucleus parameters, including the sizes and masses of objects and their families, and their tensile strengths. The physical processes occurring at these objects are considered in some detail, including the disruption of nuclei, sublimation, and ionisation, and we consider the mass, momentum, and energy loss of comets in the corona and those that venture to lower altitudes. The different components of comae and tails are described, including dust, neutral and ionised gases, their chemical reactions, and their contributions to the near-Sun environment. Comet-solar wind interactions are discussed, including the use of comets as probes of solar wind and coronal conditions in their vicinities. We address the relevance of work on comets near the Sun to similar objects orbiting other stars, and conclude with a discussion of future directions for the field and the planned ground- and space-based facilities that will allow us to address those science topics

Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters

Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio

Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter