Expression, purification and structural analysis of functional GABA transporter 1 using the baculovirus expression system

• Jing Hu,
• Chris Weise,
• Christoph Böttcher,
• Hua Fan and
• Jian Yin

Beilstein J. Org. Chem. 2017, 13, 874–882, doi:10.3762/bjoc.13.88

• , and tryptic peptides were analyzed either directly by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI–TOF MS) or guanidinated and then analyzed by MALDI. The labeled peptide peaks (Figure 2B) in the mass spectrum were identified as either GAT or GFP by matching the

Total synthesis of a Streptococcus pneumoniae serotype 12F CPS repeating unit hexasaccharide

• Peter H. Seeberger,
• Claney L. Pereira and
• Subramanian Govindan

Beilstein J. Org. Chem. 2017, 13, 164–173, doi:10.3762/bjoc.13.19

• -dimethylformamide; EtOAc: ethyl acetate; GlcA: glucouronic acid; HPLC: high-performance liquid chromatography; Lev: levulinoyl; MALDI–TOF MS: matrix-assisted laser desorption/ionization–time of flight mass spectrometry; NAP: 2-naphthylmethyl; TBS: tert-butyldimethylsilyl; THF: tetrahydrofuran; TMSOTf

Electron-transfer-initiated benzoin- and Stetter-like reactions in packed-bed reactors for process intensification

• Anna Zaghi,
• Daniele Ragno,
• Graziano Di Carmine,
• Carmela De Risi,
• Olga Bortolini,
• Pier Paolo Giovannini,
• Giancarlo Fantin and
• Alessandro Massi

Beilstein J. Org. Chem. 2016, 12, 2719–2730, doi:10.3762/bjoc.12.268

• mode by Agilent 6520 HPLC-Chip Q/TOF-MS (nanospray) using a quadrupole, a hexapole, and a time-of-flight unit to produce spectra. The capillary source voltage was set at 1700 V; the gas temperature and drying gas were kept at 350 °C and 5 L/min, respectively. The MS analyzer was externally calibrated

Determination of the absolute stereostructure of a cyclic azobenzene from the crystal structure of the precursor containing a heavy element

• Reji Thomas and
• Nobuyuki Tamaoki

Beilstein J. Org. Chem. 2016, 12, 2211–2215, doi:10.3762/bjoc.12.212

• ionization time-of-flight mass spectrometry (MALDI–TOFMS) was performed with an Applied Biosystems Voyager-DE pro instrument. Absorption spectra were recorded with an Agilent 8453 spectrophotometer and the CD spectra were recorded with a JASCO J-S720 CD spectrophotometer. High-performance liquid

Star-shaped and linear π-conjugated oligomers consisting of a tetrathienoanthracene core and multiple diketopyrrolopyrrole arms for organic solar cells

• Hideaki Komiyama,
• Chihaya Adachi and
• Takuma Yasuda

Beilstein J. Org. Chem. 2016, 12, 1459–1466, doi:10.3762/bjoc.12.142

• photoabsorption properties. Experimental General methods Matrix-assisted laser desorption ionization time-of-flight (MALDI–TOF) mass spectra were collected on a Bruker Daltonics Autoflex III spectrometer using dithranol as the matrix. Elemental analysis was carried out using a YANACO CHN coder MT-6

Artificial Diels–Alderase based on the transmembrane protein FhuA

• Hassan Osseili,
• Daniel F. Sauer,
• Klaus Beckerle,
• Marcus Arlt,
• Tomoki Himiyama,
• Tino Polen,
• Akira Onoda,
• Ulrich Schwaneberg,
• Takashi Hayashi and
• Jun Okuda

Beilstein J. Org. Chem. 2016, 12, 1314–1321, doi:10.3762/bjoc.12.124

• (polyethylene-polyethylene glycol), SDS (sodium dodecyl sulfate), TEV (Tobacco Etch Virus), MALDI–TOF–MS (matrix-assisted laser desorption/ionisation and time-of-flight mass spectrometry), FhuAΔCVFtev (FhuA Δ1-159_C545_V548_F501_tev), CD (circular dichroism), ESI-MS (electrospray ionization-mass spectrometry

Natural products from microbes associated with insects

• Christine Beemelmanns,
• Huijuan Guo,
• Maja Rischer and
• Michael Poulsen

Beilstein J. Org. Chem. 2016, 12, 314–327, doi:10.3762/bjoc.12.34

• identified as piericidin derivatives (e.g., piericidin A1 (1), Figure 3) and the chlorinated indole derivative streptochlorin (2). Imaging analysis based on a combination of laser desorption/ionization (LDI)–time of flight (TOF) mass spectrometry imaging visualized the spatial distribution of the antibiotics

Convenient preparation of high molecular weight poly(dimethylsiloxane) using thermally latent NHC-catalysis: a structure-activity correlation

• Stefan Naumann,
• Johannes Klein,
• Dongren Wang and
• Michael R. Buchmeiser

Beilstein J. Org. Chem. 2015, 11, 2261–2266, doi:10.3762/bjoc.11.246

• up, ranging from 200 000 g/mol to over 400 000 g/mol (Mn). Importantly, in all these cases very high conversion is observed. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI–ToF MS) and NMR experiments clearly show that BnOH is incorporated in the resulting PDMS (S1

Two strategies for the synthesis of the biologically important ATP analogue ApppI, at a multi-milligram scale

• Janne Weisell,
• Jouko Vepsäläinen and
• Petri A. Turhanen

Beilstein J. Org. Chem. 2015, 11, 2189–2193, doi:10.3762/bjoc.11.237

• quadrupole time-of-flight mass spectrometer using electrospray ionization (ESI) in the positive ionization mode. The purity of the products was determined from 1H and 31P NMR spectra and was ≥95% unless stated otherwise. Procedure for the preparation of isopentenyl tosylate (7): 3-Methyl-3-buten-1-ol (770 µL

Polythiophene and oligothiophene systems modified by TTF electroactive units for organic electronics

• Alexander L. Kanibolotsky,
• Neil J. Findlay and
• Peter J. Skabara

Beilstein J. Org. Chem. 2015, 11, 1749–1766, doi:10.3762/bjoc.11.191

• this compound a promising p-type organic semiconductor material. The time of flight mobility for this compound was found to increase from 1.4 × 10−6 to 1.1 × 10−5 cm2 V−1 s−1, as the electric field increases from 1 × 105 to 4 × 105 V cm−1 [92]. Compound 54 (n = 1) was tested as a solution processable p

Interactions between tetrathiafulvalene units in dimeric structures – the influence of cyclic cores

• Huixin Jiang,
• Virginia Mazzanti,
• Christian R. Parker,
• Søren Lindbæk Broman,
• Jens Heide Wallberg,
• Karol Lušpai,
• Adam Brincko,
• Henrik G. Kjaergaard,
• Anders Kadziola,
• Peter Rapta,
• Ole Hammerich and
• Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2015, 11, 930–948, doi:10.3762/bjoc.11.104

• spectrometry (MS) was performed using Matrix Assisted Laser Desorption Ionization (MALDI); TOF = time-of-flight; FT-ICR = Fourier Transform Ion Cyclotron Resonance. IR spectra were measured using the attenuated total reflectance (ATR) method on diamond. The relative peak intensities in IR spectra are

3α,5α-Cyclocholestan-6β-yl ethers as donors of the cholesterol moiety for the electrochemical synthesis of cholesterol glycoconjugates

• Aneta M. Tomkiel,
• Adam Biedrzycki,
• Jolanta Płoszyńska,
• Dorota Naróg,
• Andrzej Sobkowiak and
• Jacek W. Morzycki

Beilstein J. Org. Chem. 2015, 11, 162–168, doi:10.3762/bjoc.11.16

• spectra are reported in Supporting Information File 1; sugar protons are marked with the ‘prime’ index). Infrared spectra were recorded on a Nicolet series II Magna-IR 550 FTIR spectrometer in chloroform solutions. Mass spectra were recorded at 70 eV with a time-of-flight (TOF) AMD-604 spectrometer with

Preparation of neuroprotective condensed 1,4-benzoxazepines by regio- and diastereoselective domino Knoevenagel–[1,5]-hydride shift cyclization reaction

• László Tóth,
• Yan Fu,
• Hai Yan Zhang,
• Attila Mándi,
• Katalin E. Kövér,
• Tünde-Zita Illyés,
• Attila Kiss-Szikszai,
• Balázs Balogh,
• Tibor Kurtán,
• Sándor Antus and
• Péter Mátyus

Beilstein J. Org. Chem. 2014, 10, 2594–2602, doi:10.3762/bjoc.10.272

• concentration of the injected sample was set so that the HT value did not exceed 500 V in the HT channel down to 230 nm. IR spectra were recorded on a JASCO FTIR-4100 spectrometer and absorption bands are presented as wavenumber in cm−1. Electrospay Quadrupole Time-of-Flight HRMS measurements were performed

Synthesis and immunological evaluation of protein conjugates of Neisseria meningitidis X capsular polysaccharide fragments

• Laura Morelli,
• Damiano Cancogni,
• Marta Tontini,
• Alberto Nilo,
• Sara Filippini,
• Paolo Costantino,
• Maria Rosaria Romano,
• Francesco Berti,
• Roberto Adamo and
• Luigi Lay

Beilstein J. Org. Chem. 2014, 10, 2367–2376, doi:10.3762/bjoc.10.247

• subsequently reconstituted with 10 mM NaPi pH 7. Yields (recovered glycoprotein as determined by microBCA, Pierce Thermo): 85–95%. Loading of glycoconjugate was determined by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI–TOF MS; UltraFlex III MALDI–TOF/TOF instrument

Multivalent scaffolds induce galectin-3 aggregation into nanoparticles

• Candace K. Goodman,
• Mark L. Wolfenden,
• Pratima Nangia-Makker,
• Anna K. Michel,
• Avraham Raz and
• Mary J. Cloninger

Beilstein J. Org. Chem. 2014, 10, 1570–1577, doi:10.3762/bjoc.10.162

• functionalized dendrimers were characterized by MALDI–TOF–MS (matrix-assisted laser desorption time of flight mass spectrometry). The average numbers of sugars that were incorporated are shown in Scheme 2. The loadings were determined by both the changes in weight average molecular weight (Mw) upon addition of 1

• , m = multiplet, app = apparent), integration, coupling constants (in Hz) and assignments. Sample NMR spectra are provided in Figures S2 through S6, Supporting Information File 1. MALDI–TOF mass spectrometry MALDI mass spectra were acquired using a Bruker Biflex-III time-of-flight mass spectrometer

Biantennary oligoglycines and glyco-oligoglycines self-associating in aqueous medium

• Svetlana V. Tsygankova,
• Alexander A. Chinarev,
• Alexander B. Tuzikov,
• Nikolai Severin,
• Alexey A. Kalachev,
• Juergen P. Rabe,
• Alexandra S. Gambaryan and
• Nicolai V. Bovin

Beilstein J. Org. Chem. 2014, 10, 1372–1382, doi:10.3762/bjoc.10.140

• chemical shifts was calibrated against the signals of residual protons of solvents (CDCl3: δ 7.26 ppm; DMSO-d6: δ 2.50 ppm; D2O: δ 4.75 ppm). Mass-spectra were recorded on the time-of-flight spectrometer Vision-2000 (Thermo Bioanalysis, UK) with MALDI with 2,6-dihydroxybenzoic acid as reference. Raman

Automated solid-phase peptide synthesis to obtain therapeutic peptides

• Veronika Mäde,
• Sylvia Els-Heindl and
• Annette G. Beck-Sickinger

Beilstein J. Org. Chem. 2014, 10, 1197–1212, doi:10.3762/bjoc.10.118

• major prerequisite for the success of SPPS, both with respect to analytics and preparative purification [25]. Furthermore, high-quality mass spectrometry (MS) with soft ionization techniques such as MALDI–TOF (matrix-assisted laser desorption ionization – time of flight) and ESI (electrospray ionization

cis–trans Isomerization of silybins A and B

• Michaela Novotná,
• Radek Gažák,
• David Biedermann,
• Florent Di Meo,
• Petr Marhol,
• Marek Kuzma,
• Lucie Bednárová,
• Kateřina Fuksová,
• Patrick Trouillas and
• Vladimír Křen

Beilstein J. Org. Chem. 2014, 10, 1047–1063, doi:10.3762/bjoc.10.105

• -Ultra FTMS with ESI ionization. The high-resolution ESI–MS spectra were measured by using a GCT Premier benchtop orthogonal acceleration time-of-flight mass spectrometer. Optical rotations were measured with a Rudolph Autopol polarimeter in acetone at 25 °C, and ECD spectra were recorded in a Jasco-815

Oligomeric epoxide–amine adducts based on 2-amino-N-isopropylacetamide and α-amino-ε-caprolactam: Solubility in presence of cyclodextrin and curing properties

• Julian Fischer and
• Helmut Ritter

Beilstein J. Org. Chem. 2013, 9, 2803–2811, doi:10.3762/bjoc.9.315

• spectrometry (ESIMS) was conducted on a Bruker maXis 4G mass spectrometer and matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF-MS) on a Bruker Dalomics Ultraflex 1 mass spectrometer. Melting points were obtained using a Büchi Melting Point B-545 apparatus at a heating

Stability of SG1 nitroxide towards unprotected sugar and lithium salts: a preamble to cellulose modification by nitroxide-mediated graft polymerization

• Guillaume Moreira,
• Laurence Charles,
• Mohamed Major,
• Florence Vacandio,
• Yohann Guillaneuf,
• Catherine Lefay and
• Didier Gigmes

Beilstein J. Org. Chem. 2013, 9, 1589–1600, doi:10.3762/bjoc.9.181

• set to +5,500 V and the cone voltage to +20 V. Air was used as the nebulizing gas (10 psi), while nitrogen was the curtain gas (20 psi). In this hybrid instrument, ions were measured by using an orthogonal acceleration time-of-flight (oa-TOF) mass analyser. Instrument control, data acquisition, and

A study on electrospray mass spectrometry of fullerenol C₆₀(OH)₂₄

• Mihaela Silion,
• Andrei Dascalu,
• Mariana Pinteala,
• Bogdan C. Simionescu and
• Cezar Ungurenasu

Beilstein J. Org. Chem. 2013, 9, 1285–1295, doi:10.3762/bjoc.9.145

• analysis Mass spectrometry results were obtained using an Agilent 6520 Series Accurate-Mass Quadrupole Time-of-Flight (Q-TOF) LC/MS. The solutions were introduced into the electrospray ion source (ESI) after HPLC separation via a 4:1 splitter at a flow-rate of 0.2 mL/min. During the experiments, the

Linkage of α-cyclodextrin-terminated poly(dimethylsiloxanes) by inclusion of quasi bifunctional ferrocene

• Helmut Ritter,
• Berit Knudsen and
• Valerij Durnev

Beilstein J. Org. Chem. 2013, 9, 1278–1284, doi:10.3762/bjoc.9.144

• -toluenesulfonyl)-6-deoxy)-α-cyclodextrin (α-tosyl-CD), mono-(6-N-allylamino)-6-deoxy)-α-cyclodextrin (AAm-α-CD) and mono-((6-N-allylamino)-6-deoxy)-peracetylated-α-cyclodextrin (AAm-Ac-α-CD) [21] were synthesized according to the literature. MALDI–TOF mass spectra were recorded with a Bruker Ultraflex time-of

• -flight mass spectrometer. The device operates both in the linear mode and in reflector mode with a 337 nm nitrogen laser. The samples were dissolved in a suitable solvent. A dithranol (DIT) or 2,5-dihydroxybenzoic acid (DHB) matrix was used. The IR spectra were recorded with a Fourier transform infrared

Superstructures of fluorescent cyclodextrin via click-reaction

• Arkadius Maciollek,
• Helmut Ritter and
• Rainer Beckert

Beilstein J. Org. Chem. 2013, 9, 827–831, doi:10.3762/bjoc.9.94

• -of-flight mass spectrometry (MALDI–TOFMS) was performed on a Bruker Ultraflex TOF mass spectrometer. Ions were formed with a pulsed nitrogen laser (25 Hz, 337 nm) and the molecular masses were recorded in linear mode. 2,5-Dihydroxybenzoic acid (DBH) in acetonitrile/water was used as a matrix. Mass

• from Deutero GmbH, Germany. 1H NMR spectra were recorded on a Bruker Avance DRX 300 at 20 °C, shifts (δ) are given relative to signals arising from the solvent. FT IR spectra were recorded on a Nicolet 6700 FT IR spectrometer equipped with an ATR unit. Matrix-assisted laser desorption/ionization-time

Photoionisation of the tropyl radical

• Kathrin H. Fischer,
• Patrick Hemberger,
• Andras Bodi and
• Ingo Fischer

Beilstein J. Org. Chem. 2013, 9, 681–688, doi:10.3762/bjoc.9.77

• cyclopentadienyl radical produced as a side product in the pyrolysis. Above 10.55 eV, on the other hand, the intensity rises significantly and the time-of-flight peak shape becomes asymmetric, as visible in the lower trace of Figure 5. Such an asymmetry indicates that the ion is a dissociation product of a

• threshold photoelectrons by detecting them in coincidence with ions. The spectrometer is a combination of a Wiley–McLaren time-of-flight (TOF) mass spectrometer [48] and a velocity map imaging setup [49]. The latter is equipped with a position sensitive detector with a delay line anode (Roentdek DLD40

An improved synthesis of a fluorophosphonate–polyethylene glycol–biotin probe and its use against competitive substrates

• Hao Xu,
• Hairat Sabit,
• Gordon L. Amidon and
• H. D. Hollis Showalter

Beilstein J. Org. Chem. 2013, 9, 89–96, doi:10.3762/bjoc.9.12

• analysis was performed by using a Waters LCT time-of-flight mass spectrometry instrument. Flash column chromatography was performed with silica gel (220–240 mesh). Thin-layer chromatography (TLC) was performed on silica gel GHLF plates (250 microns) purchased from Analtech. Developed TLC plates were