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Search for "liquid chromatography" in Full Text gives 142 result(s) in Beilstein Journal of Organic Chemistry.

Studies on the photodegradation of red, green and blue phosphorescent OLED emitters

  • Susanna Schmidbauer,
  • Andreas Hohenleutner and
  • Burkhard Kƶnig

Beilstein J. Org. Chem. 2013, 9, 2088–2096, doi:10.3762/bjoc.9.245

Graphical Abstract
  • films. To gain information on the chemical degradation mechanisms, we tried to identify deterioration products by liquid chromatography mass spectrometry (LC–MS) and other analytical methods where applicable. Results and Discussion For our investigations, we chose the four iridium complexes depicted in
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Published 11 Oct 2013

New tridecapeptides of the theonellapeptolide family from the Indonesian sponge Theonella swinhoei

  • Annamaria Sinisi,
  • Barbara Calcinai,
  • Carlo Cerrano,
  • Henny A. Dien,
  • Angela Zampella,
  • Claudio D’Amore,
  • Barbara Renga,
  • Stefano Fiorucci and
  • Orazio Taglialatela-Scafati

Beilstein J. Org. Chem. 2013, 9, 1643–1651, doi:10.3762/bjoc.9.188

Graphical Abstract
  • were determined with the HSQC experiment. Two and three bond 1H/13C connectivities were determined by gradient 2D HMBC experiments optimized for a 2,3J = 9 Hz. Medium-pressure liquid chromatography was performed on a Büchi apparatus by using a silica gel (230–400 mesh) column. HPLC was achieved on a
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Published 13 Aug 2013

Diastereoselective synthesis of nitroso acetals from (S,E)-γ-aminated nitroalkenes via multicomponent [4 + 2]/[3 + 2] cycloadditions promoted by LiCl or LiClO4

  • Leandro Lara de Carvalho,
  • Robert Alan Burrow and
  • Vera LĆŗcia Patrocinio Pereira

Beilstein J. Org. Chem. 2013, 9, 838–845, doi:10.3762/bjoc.9.96

Graphical Abstract
  • dimensions of 2.0 cm Ćø Ɨ 15.0 cm. The overall cycloadditions were monitored by thin-layer chromatography (silica gel 60 F254 MerckĀ® twice eluted with ethyl acetate/hexane 1:4 v/v) and the visualization was achieved by using iodine impregnated on silica gel or UV light (254 nm). Liquid chromatography was
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Published 30 Apr 2013

Synthesis and evaluation of cell-permeable biotinylated PU-H71 derivatives as tumor Hsp90 probes

  • Tony Taldone,
  • Anna Rodina,
  • Erica M. DaGama Gomes,
  • Matthew Riolo,
  • Hardik J. Patel,
  • Raul Alonso-Sabadell,
  • Danuta Zatorska,
  • Maulik R. Patel,
  • Sarah Kishinevsky and
  • Gabriela Chiosis

Beilstein J. Org. Chem. 2013, 9, 544–556, doi:10.3762/bjoc.9.60

Graphical Abstract
  • = quartet, br = broad, m = multiplet), coupling constant (Hz), integration. High-resolution mass spectra were recorded on a Waters LCT Premier system. Low-resolution mass spectra were obtained on a Waters Acquity Ultra Performance LC with electrospray ionization and SQ detector. High-performance liquid
  • chromatography analyses were performed on a Waters Autopurification system with PDA, MicroMass ZQ, and ELSD detector, and a reversed-phase column (Waters X-Bridge C18, 4.6 Ɨ 150 mm, 5 µm) using a gradient of (a) H2O + 0.1% TFA and (b) CH3CN + 0.1% TFA, 5 to 95% b over 13 minutes at 1.2 mL/min. All reactions were
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Published 15 Mar 2013

Thermotropic and lyotropic behaviour of new liquid-crystalline materials with different hydrophilic groups: synthesis and mesomorphic properties

  • Alexej Bubnov,
  • Miroslav KaÅ”par,
  • Věra HamplovĆ”,
  • Ute Dawin and
  • Frank Giesselmann

Beilstein J. Org. Chem. 2013, 9, 425–436, doi:10.3762/bjoc.9.45

Graphical Abstract
  • purity of the compounds was checked by high performance liquid chromatography, which was carried out with an Ecom HPLC chromatograph by using a silica-gel column (Separon 7 μm, 3 Ɨ 150, Tessek) with a 98/2 mixture of toluene and methanol as eluent (typical flow rate 1 mL/min, retention times for
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Published 25 Feb 2013

From bead to flask: Synthesis of a complex β-amido-amide for probe-development studies

  • Kevin S. Martin,
  • Cristian Soldi,
  • Kellan N. Candee,
  • Hiromi I. Wettersten,
  • Robert H. Weiss and
  • Jared T. Shaw

Beilstein J. Org. Chem. 2013, 9, 260–264, doi:10.3762/bjoc.9.31

Graphical Abstract
  • acid core was attached to Rink-amide resin and carried through to 1 by a series of elaboration and tagging steps [14][15]. Synthetic intermediates in this route were not characterized, and 1 was ultimately purified by high-performance liquid chromatography and partially characterized by matrix-assisted
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Published 06 Feb 2013

Multivalent display of the antimicrobial peptides BP100 and BP143

  • Imma Güell,
  • Rafael Ferre,
  • Kasper K. SĆørensen,
  • Esther Badosa,
  • Iteng Ng-Choi,
  • Emilio Montesinos,
  • Eduard BardajĆ­,
  • Lidia Feliu,
  • Knud J. Jensen and
  • Marta Planas

Beilstein J. Org. Chem. 2012, 8, 2106–2117, doi:10.3762/bjoc.8.237

Graphical Abstract
  • was obtained. It has been previously reported that silanes under acidic conditions can promote the reduction of aldehydes [27]. Cleavage of the peptidyl resins with TFA/H2O (95:5) followed by purification by reversed-phase high-performance liquid chromatography (RP-HPLC) afforded peptide aldehydes 4
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Published 03 Dec 2012

The use of glycoinformatics in glycochemistry

  • Thomas Lütteke

Beilstein J. Org. Chem. 2012, 8, 915–929, doi:10.3762/bjoc.8.104

Graphical Abstract
  • data with a variety of tools and information on other biomolecules. The KEGG portal has a particular focus on biosynthetic pathways. EUROCarbDB was developed to store primary data of mass spectrometry (MS), NMR and high performance liquid chromatography (HPLC) experiments. In addition to data imported
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Review
Published 21 Jun 2012

Triterpenoid saponins from the roots of Acanthophyllum gypsophiloides Regel

  • Elena A. Khatuntseva,
  • Vladimir M. Men’shov,
  • Alexander S. Shashkov,
  • Yury E. Tsvetkov,
  • Rodion N. Stepanenko,
  • Raymonda Ya. Vlasenko,
  • Elvira E. Shults,
  • Genrikh A. Tolstikov,
  • Tatjana G. Tolstikova,
  • Dimitri S. Baev,
  • Vasiliy A. Kaledin,
  • Nelli A. Popova,
  • Valeriy P. Nikolin,
  • Pavel P. Laktionov,
  • Anna V. Cherepanova,
  • Tatiana V. Kulakovskaya,
  • Ekaterina V. Kulakovskaya and
  • Nikolay E. Nifantiev

Beilstein J. Org. Chem. 2012, 8, 763–775, doi:10.3762/bjoc.8.87

Graphical Abstract
  • solution (Fluka). A syringe injection was used for solutions in acetonitrile, methanol, or water (flow rate 3 μL/min). Nitrogen was applied as a dry gas; the interface temperature was set to 180 °C. High-performance liquid chromatography (HPLC) was carried out on a C18 reversed-phase column (Ascentis C18
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Published 23 May 2012

Cyanoethylation of the glucans dextran and pullulan: Substitution pattern and formation of nanostructures and entrapment of magnetic nanoparticles

  • Kathrin Fiege,
  • Heinrich Lünsdorf,
  • Sevil Atarijabarzadeh and
  • Petra Mischnick

Beilstein J. Org. Chem. 2012, 8, 551–566, doi:10.3762/bjoc.8.63

Graphical Abstract
  • infrared spectroscopy (ATR–IR). Gas–liquid chromatography (GLC) in combination with mass spectrometry (MS) was employed for the analysis of glucose derivatives after depolymerization of the cyanoethylglucans. The DS of heterogenic atoms containing polysaccharide derivatives can be followed by elementary
  • residual solvent signals. ATR–IR spectra were recorded by using a Bruker Tensor 27 attenuated total reflectance infrared (ATR–IR) spectrometer. Elementary analysis (EA) was performed on a Thermoquest EA 1112 analyser. The data given is always the average of two measurements. Gas–liquid chromatography (GLC
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Published 13 Apr 2012

Mutational analysis of a phenazine biosynthetic gene cluster in Streptomyces anulatus 9663

  • Orwah Saleh,
  • Katrin Flinspach,
  • Lucia Westrich,
  • Andreas Kulik,
  • Bertolt Gust,
  • Hans-Peter Fiedler and
  • Lutz Heide

Beilstein J. Org. Chem. 2012, 8, 501–513, doi:10.3762/bjoc.8.57

Graphical Abstract
  • concentrated in vacuo to an aqueous residue, adjusted to pH 4.0 by using HCl and extracted with ethyl acetate. The ethyl acetate extract was first treated with petrol ether. After evaporation, the extract residue was fractioned by using a liquid chromatography system with a Sephadex LH20 column (2.5 Ɨ 90 cm
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Published 04 Apr 2012

Conserved and species-specific oxylipin pathways in the wound-activated chemical defense of the noninvasive red alga Gracilaria chilensis and the invasive Gracilaria vermiculophylla

  • Martin Rempt,
  • Florian Weinberger,
  • Katharina Grosser and
  • Georg Pohnert

Beilstein J. Org. Chem. 2012, 8, 283–289, doi:10.3762/bjoc.8.30

Graphical Abstract
  • measurements were performed on an UPLC–MS system equipped with a 2996 PDA detector and a Q-tof micro ESIMS (Waters, Manchester, UK). For separation of the analytes, a BEH C18 column (2.1 Ɨ 50 mm, particle size 1.7 µm) was used. LC on a semipreparative column was carried out by using a LC-8A liquid
  • chromatography system from Shimadzu (Duisburg, Germany) equipped with a SPD-10AV UV–vis detector. A Licro ChartĀ® 250-10 PurosphereĀ® RP-18 endcapped column (particle size 5µm) supplied by Merck (Darmstadt, Germany) was used for separation. HPLC separation on an analytical scale was performed on the same LC system
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Published 21 Feb 2012

Marilones A–C, phthalides from the sponge-derived fungus Stachylidium sp.

  • Celso Almeida,
  • Stefan Kehraus,
  • Miguel PrudĆŖncio and
  • Gabriele M. Kƶnig

Beilstein J. Org. Chem. 2011, 7, 1636–1642, doi:10.3762/bjoc.7.192

Graphical Abstract
  • , 70–230 mesh) was used for vacuum liquid chromatography (VLC). Columns were wet-packed under vacuum with petroleum ether (PE). Before applying the sample solution, the columns were equilibrated with the first designated eluent. Standard columns for crude extract fractionation had dimensions of 13 Ɨ 4
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Letter
Published 05 Dec 2011

Asymmetric Au-catalyzed cycloisomerization of 1,6-enynes: An entry to bicyclo[4.1.0]heptene

  • Alexandre Pradal,
  • Chung-Meng Chao,
  • Patrick Y. Toullec and
  • VĆ©ronique Michelet

Beilstein J. Org. Chem. 2011, 7, 1021–1029, doi:10.3762/bjoc.7.116

Graphical Abstract
  • were recorded on a Bruker AV 300 instrument. All signals were expressed as ppm (Ī“) and internally referenced to residual proton solvent signals. Coupling constants (J) are reported in Hz and refer to apparent peak multiplicities. Enantiomeric excesses were determined by high pressure liquid
  • chromatography analyses (HPLC) on Waters instruments (Waters 486 detector, 717 autosampler equipped with Daicel Chiralcel OD-H, OJ and Chiralpak IA, AD, Ī» = 215 nm). Optical rotation measurements were conducted on a Perkin–Elmer 241 polarimeter at 589 nm. Enynes 5 [71], 2a [72], 2b–e [46], 1a [73], 1b [74], 1c,d
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Published 26 Jul 2011

Continuous flow hydrogenation using polysilane-supported palladium/alumina hybrid catalysts

  • Hidekazu Oyamada,
  • Takeshi Naito and
  • ShÅ« Kobayashi

Beilstein J. Org. Chem. 2011, 7, 735–739, doi:10.3762/bjoc.7.83

Graphical Abstract
  • continuous flow reactor and an image of the top of the column are shown in Figure 1. A high performance liquid chromatography (HPLC) pump was used to feed the substrate into the central hole in the top of the column, which was filled with the Pd/(PSi–Al2O3) catalyst. Hydrogen gas was introduced into the six
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Published 31 May 2011

Towards racemizable chiral organogelators

  • Jian Bin Lin,
  • Debarshi Dasgupta,
  • Seda Cantekin and
  • Albertus P. H. J. Schenning

Beilstein J. Org. Chem. 2010, 6, 960–965, doi:10.3762/bjoc.6.107

Graphical Abstract
  • hydrogen-bond interactions between the peptide head groups of neighbouring organogelator molecules. The enantiomerically pure organogelator can be racemized by the base DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) as was evident from chiral high-performance liquid chromatography analysis. Keywords: chirality
  • -didodecyloxybenzaldehyde [19] led to compound 3 in 50% yield (Scheme 1). Both R-3 and S-3 were purified by recrystallization and fully characterized. Chiral high-performance liquid chromatography (HPLC) showed an ee of more than 99% for the enantiomers. Interestingly, 1H NMR spectroscopy in chloroform revealed that the
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Published 06 Oct 2010

Preparation and NMR spectra of four isomeric diformyl[2.2]paracyclophanes (cyclophanes 66)

  • Ina Dix,
  • Henning Hopf,
  • Thota B. N. Satyanarayana and
  • Ludger Ernst

Beilstein J. Org. Chem. 2010, 6, 932–937, doi:10.3762/bjoc.6.104

Graphical Abstract
  • beginning to attract the attention of other research groups [6][7][10][11][12][13]. Results and Discussion Separation of the diformyl[2.2]paracyclophanes 4 We have separated the isomer mixture 4 by different methods. The easiest way is by middle pressure liquid chromatography (MPLC), which readily affords
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Published 29 Sep 2010
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