Catalysis of linear alkene metathesis by Grubbs-type ruthenium alkylidene complexes containing hemilabile α,α-diphenyl-(monosubstituted-pyridin-2-yl)methanolato ligands

• Tegene T. Tole,
• Johan H. L. Jordaan and
• Hermanus C. M. Vosloo

Beilstein J. Org. Chem. 2019, 15, 194–209, doi:10.3762/bjoc.15.19

• /2.11 (3 × s, 3 × 6H, H of 6-CH3 on mesityl), 1.18 (s, 3H, H of CH3 on C5H3N); MALDI–MS (m/z): [M]+ 807.2646 (C47H48ClN3ORu); IR (in cm−1): v(OH, moisture) = 3386, v(=C-H) = 3054, 3018, 776, v(CH3) = 2921, 2852, 1396, v(C=N) = 1604, v(C=C) = 1584–1443, v(C-N) = 1254, v(C-O) = 1157; 13C NMR (150 MHz) δ

• × 6H, 6-CH3 of mesityl), 2.17 (s, 3H, H of CH3 on C5H3N); MALDI–MS (m/z): [M]+ 807.2660 (C47H48ClN3ORu); IR (in cm−1): v(OH, moisture) = 3391, v(=C-H) = 3055, 3020, 755, v(CH3) = 2920, 2849, 1377, v(C=N) = 1605, v(C=C) = 1481–1410, v(C-N) = 1261, v(C-O) = 1163; 13C NMR (150 MHz, CDCl3) δ 291.2, 214.5

• , para H of 2Ph), 6.99 (m, 1H, H-5 of C5H3N), 6.73 (m, 4H, meta H of 2Ph), 6.73 (m, 2H, para H of 2Ph), 6.43 (d, J = 7.7 Hz, ortho H of Ru=CHPh), 4.01–3.89 (m, 4H, H of NHC), 2.57/2.19/2.16 (3 × s, 3 × 6H, 6-CH3 of mesityl), 2.90 (s, 3H, H of OCH3); MALDI–MS (m/z): [M]+ 823.2417 (C47H48ClN3O2Ru); IR (in

Olefin metathesis catalysts embedded in β-barrel proteins: creating artificial metalloproteins for olefin metathesis

• Daniel F. Sauer,
• Johannes Schiffels,
• Takashi Hayashi,
• Ulrich Schwaneberg and
• Jun Okuda

Beilstein J. Org. Chem. 2018, 14, 2861–2871, doi:10.3762/bjoc.14.265

• C545. Furthermore, E501 was substituted by phenylalanine to prevent coordination of the Glu side chain to the metal site and deactivation of the catalyst. Two specific TEV (Tobacco Etch Virus protease) cleavage sites were further introduced into loops 7 and 8 to facilitate MALDI–TOF–MS analysis. The

Copolymerization of epoxides with cyclic anhydrides catalyzed by dinuclear cobalt complexes

• Yo Hiranoi and
• Koji Nakano

Beilstein J. Org. Chem. 2018, 14, 2779–2788, doi:10.3762/bjoc.14.255

• spectrometry (MALDI–TOF MS, Figure 2). Several series of signals with a regular interval of 206.1 (repeating unit) were observed in the lower mass range. The m/z value of each signal of the major distribution corresponds with [166.0 (C6F5COO, initiating group) + 206.1n (repeating unit) + 59.1 (CH2CHMeOH

• DAICEL CHIRALCEL® IA-3 column [tR = 12.65 min for the (S)-isomer and 14.50 min for the (R)-isomer (flow rate: 1.0 mL; eluent: hexane/iPrOH 95:5)]. Structures of cobalt–salen complexes 1–4. MALDI–TOF mass spectrum of the PO/PA copolymer. The low molecular weight copolymer for MS analysis was prepared by

Non-metal-templated approaches to bis(borane) derivatives of macrocyclic dibridgehead diphosphines via alkene metathesis

• Tobias Fiedler,
• Michał Barbasiewicz,
• Michael Stollenz and
• John A. Gladysz

Beilstein J. Org. Chem. 2018, 14, 2354–2365, doi:10.3762/bjoc.14.211

• (w), 1061 (m), 803 (w), 722 (w) cm−1; MS (MALDI+, THAP) [56]: 651.6 ([M – 2BH3 + 1]+, 100%). (6·2BH3; 0.101 g, 0.149 mmol, 10%), white solid, mp 96 °C (capillary). Anal. calcd for C42H90B2P2 (678.73): C, 74.32; H, 13.37; found: C, 73.92; H, 13.47. The identity of this compound, which has been

• ; MS (MALDI+, THAP) [56]: 702.0 ([M + Na]+, 98%), 666.0 ([M − BH3 + 1]+, 100%). Metathesis/hydrogenation of (H2C=CH(CH2)6)2(H3B)P((CH2)14)P(BH3)((CH2)6CH=CH2)2 (11·2BH3; Scheme 5 [32]). Diphosphine diborane 11·2BH3 (1.222 g, 1.672 mmol), CH2Cl2 (1700 mL; the resulting solution was 0.0010 M in 11·2BH3

Semi-synthesis and insecticidal activity of spinetoram J and its D-forosamine replacement analogues

• Kai Zhang,
• Jiarong Li,
• Honglin Liu,
• Haiyou Wang and
• Lamusi A

Beilstein J. Org. Chem. 2018, 14, 2321–2330, doi:10.3762/bjoc.14.207

• , 15.00, 8.36; MS (MALDI) m/z: [M + H]+ calcd for C41H67NO10, 734.483774; found, 734.483663. Preparation of aglycone of 5,6-dihydrospinosyn A 2 Compound 1 (2.15 g, 3.64 mmol) was added to a solution of 60 mL MeOH and 130 mL 8 N H2SO4, then the mixture were heated to reflux for 4 hours. After the mixture

• , 71.25, 70.50, 52.47, 49.11, 47.28, 46.21, 42.04, 41.23, 40.26, 40.06, 38.50, 33.95, 31.75, 28.83, 27.46, 26.05, 23.45, 21.13, 14.64, 8.39; MS (MALDI) m/z: [M + Na]+ calcd for C24H36O5, 427.245495; found, 427.245611. Preparation of 3-ethoxy-2,4-dimethoxyrhamnosyltrichoroacetimidate (3) 3-O-Ethyl-2,4-di-O

• , 95.79, 82.19, 82.01, 79.68, 79.54, 78.51, 78.39, 75.70, 72.70, 68.68, 67.96, 65.68, 61.02, 60.41, 59.23, 59.02, 50.26, 48.19, 47.07, 46.37, 43.52, 40.79, 39.60, 38.80, 38.14, 34.86, 34.22, 31.59, 30.62, 28.05, 26.94, 24.68, 22.66, 17.85, 17.72, 15.76, 15.69, 14.20, 9.41; MS (MALDI) m/z: [M + Na]+ calcd

Synthesis of new p-tert-butylcalix[4]arene-based polyammonium triazolyl amphiphiles and their binding with nucleoside phosphates

• Vladimir A. Burilov,
• Guzaliya A. Fatikhova,
• Mariya N. Dokuchaeva,
• Ramil I. Nugmanov,
• Diana A. Mironova,
• Pavel V. Dorovatovskii,
• Victor N. Khrustalev,
• Svetlana E. Solovieva and
• Igor S. Antipin

Beilstein J. Org. Chem. 2018, 14, 1980–1993, doi:10.3762/bjoc.14.173

• established by 1H and 13C NMR spectroscopy as well as by IR spectroscopy and MALDI–TOF mass spectrometry. Their compositions were determined by elementary analysis. A standard set of signals typical for distal disubstituted calixarenes was found in the 1H NMR spectra of 4a and b (Supporting Information File 1

• appear as a singlet at 6.29 ppm. The signals of the bridge methylene protons appear as two doublets at 4.39–4.40 and 3.09–3.10 ppm. The presence of the azide groups was confirmed by valence asymmetric bond vibrations at 2109 cm−1 in the IR spectra of 4 and 8. The MALDI mass spectra of all obtained azides

• or DMSO-d6) as internal standard. MALDI mass spectra were measured on an UltraFlex III TOF/TOF with PNA matrix, laser Nd:YAG, λ = 355 nm. The IR spectra were recorded on a Bruker Vector-22 spectrometer. Samples were prepared as suspension in mineral oil or as thin films, obtained from chloroform

Diazirine-functionalized mannosides for photoaffinity labeling: trouble with FimH

• Femke Beiroth,
• Tomas Koudelka,
• Thorsten Overath,
• Stefan D. Knight,
• Andreas Tholey and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2018, 14, 1890–1900, doi:10.3762/bjoc.14.163

• . Subsequently, the solution was irradiated under ice cooling with a medium pressure mercury vapor lamp for 10 min. Afterwards, 50 µL double distilled water were added and 2 µL of this solution given to 20 µL of a 0.1% trifluoroacetic acid (TFA) solution, desalted with a C18 µZipTip and spotted on a MALDI-plate

• together with 5 mg/mL α-cyano-4-hydroxycinnamic acid (HCCA) matrix (70% ACN in 0.1% TFA solution in double distilled water). MALDI–TOF MS was performed on a AB 5800 MS (AB Sciex, Darmstadt, Germany) in positive ion mode. FimHtr FimHtr (3.36 nmol) was dissolved in PBS buffer (pH 7.8). Ligand 3 was dissolved

• signals were done using 2D experiments (COSY, HSQC and HMBC). IR spectra were measured with a Perkin Elmer FT IR Paragon 1000 (KBr). Optical rotation values were determined with a Perkin-Elmer polarimeter (589 nm, length of cuvette: 1 dm). MS analysis of synthetic products were carried out with a MALDI

Defining the hydrophobic interactions that drive competence stimulating peptide (CSP)-ComD binding in Streptococcus pneumoniae

• Bimal Koirala,
• Robert A. Hillman,
• Erin K. Tiwold,
• Michael A. Bertucci and
• Yftah Tal-Gan

Beilstein J. Org. Chem. 2018, 14, 1769–1777, doi:10.3762/bjoc.14.151

• desorption ionization time-of-flight mass spectrometry (MALDI–TOF MS) data were obtained on either a Bruker Autoflex or Bruker Microflex spectrometer equipped with a 60 Hz nitrogen laser and a reflectron. In positive ion mode, the acceleration voltage on Ion Source 1 was 19.01 kV. Exact mass (EM) data were

Synthesis and photophysical studies of a multivalent photoreactive Ru^II-calix[4]arene complex bearing RGD-containing cyclopentapeptides

• Sofia Kajouj,
• Lionel Marcelis,
• Alice Mattiuzzi,
• Adrien Grassin,
• Damien Dufour,
• Pierre Van Antwerpen,
• Didier Boturyn,
• Eric Defrancq,
• Mathieu Surin,
• Julien De Winter,
• Pascal Gerbaux,
• Ivan Jabin and
• Cécile Moucheron

Beilstein J. Org. Chem. 2018, 14, 1758–1768, doi:10.3762/bjoc.14.150

• mixture was then analyzed by MALDI mass spectrometry (HRMS, Figure 6). Alongside the parent conjugate 9 ions, ionized species at higher mass-to-charge ratio (m/z = 4625.9) are detected and formally correspond to the addition of GMP minus two hydrogen atoms. The comparison between the experimental and

• ; source temperature, 150 °C and desolvation temperature, 200 °C. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-ToF) mass spectra were recorded using a Waters QToF Premier mass spectrometer equipped with a Nd-YAG laser of 355 nm with a maximum pulse energy of 65 μJ delivered to the

• 500 ns after the laser pulse (gray, top) and 1 µs after the laser pulse in the presence of 10 mM GMP (purple, bottom). MALDI–MS analysis of a solution containing conjugate 9 and GMP after continuous light irradiation. In the inset, the experimental (bottom) and theoretical (top) isotope distributions

Selective carboxylation of reactive benzylic C–H bonds by a hypervalent iodine(III)/inorganic bromide oxidation system

• Toshifumi Dohi,
• Shohei Ueda,
• Kosuke Iwasaki,
• Yusuke Tsunoda,
• Koji Morimoto and
• Yasuyuki Kita

Beilstein J. Org. Chem. 2018, 14, 1087–1094, doi:10.3762/bjoc.14.94

• , 22.1, 56.3, 71.3, 110.3, 111.2, 113.3, 127.6, 128.7, 135.8, 156.0, 170.2 ppm; IR (KBr): 2984, 2158, 1741, 1603, 1499, 1370, 1291, 1242, 1208, 1062, 1023 cm−1; HRMS (MALDI): [M + Na]+ calcd for C12H13NO3SNa, 274.0507; found, 274.0508. Representative experimental procedure for the benzylic C–H

Synthesis and stability of strongly acidic benzamide derivatives

• Frederik Diness,
• Niels J. Bjerrum and
• Mikael Begtrup

Beilstein J. Org. Chem. 2018, 14, 523–530, doi:10.3762/bjoc.14.38

• Bruker 500 MHz spectrometer at 298 K with methanol-d4, DMSO-d6 or hexafluorobenzene as internal standard. High-resolution mass spectrometry (HRMS) was performed on a Bruker MALDI–TOF spectrometer. General procedure Benzoyl chloride (10.0 mmol) in Et2O (10 mL) was added dropwise to a solution of

Hydrolysis, polarity, and conformational impact of C-terminal partially fluorinated ethyl esters in peptide models

• Vladimir Kubyshkin and
• Nediljko Budisa

Beilstein J. Org. Chem. 2017, 13, 2442–2457, doi:10.3762/bjoc.13.241

• high-resolution electrospray-orbitrap mass spectrometry ionization (HRMS) for all peptides except hexalysine peptides 10a–c, which produced no distinguishable molecular ions. For cationic peptides 9a–c and 10a–c, additional MALDI–TOF analysis confirmed the molecular assignment. Diffusion coefficients

• 679.3416; logD, calcd for [M] −9.465; found, −9.467 ± 0.027. Ac(Lys)3OH∙3HCl, 9a. HRMS: calcd for [M + 3H]3+ 149.1093; found, 149.1096; MALDI–TOF: calcd for [M + H]+ 445.3; found, 445.2; logD, calcd for [M + 3H+] −9.410; found, −9.442 ± 0.025. Ac(Lys)6OH∙6HCl, 10a. MALDI–TOF: calcd for [M + H]+ 829.6

• ; found, 829.5; logD, calcd for [M + 6H+] −9.499; found, −9.607 ± 0.038. Ac(Lys)3OCH2CHF2∙3HCl, 9b. HRMS: calcd for [M + 3H]3+ 170.4468; found, 170.4474; MALDI–TOF: calcd for [M + H]+ 509.3; found, 509.2; logD, calcd for [M + 3H+] −9.429; found, −9.439 ± 0.021; τ½ = 5.0 ± 0.3 (4.5 ± 0.5) days (buffered

Structure–property relationships and third-order nonlinearities in diketopyrrolopyrrole based D–π–A–π–D molecules

• Jan Podlesný,
• Lenka Dokládalová,
• Oldřich Pytela,
• Adam Urbanec,
• Milan Klikar,
• Numan Almonasy,
• Tomáš Mikysek,
• Jaroslav Jedryka,
• Iwan V. Kityk and
• Filip Bureš

Beilstein J. Org. Chem. 2017, 13, 2374–2384, doi:10.3762/bjoc.13.235

• spectra, HR-MALDI-MS spectra, CV curves, UV–vis absorption/emission spectra, and HOMO/LUMO localizations. Acknowledgements This research was supported by the Technology Agency of the Czech Republic (TE01020022, Flexprint).

Solvent-free copper-catalyzed click chemistry for the synthesis of N-heterocyclic hybrids based on quinoline and 1,2,3-triazole

• Martina Tireli,
• Silvija Maračić,
• Stipe Lukin,
• Marina Juribašić Kulcsár,
• Dijana Žilić,
• Mario Cetina,
• Ivan Halasz,
• Silvana Raić-Malić and
• Krunoslav Užarević

Beilstein J. Org. Chem. 2017, 13, 2352–2363, doi:10.3762/bjoc.13.232

• Information File 1, Figures S1–S5, S10). High-resolution mass spectra of the final compounds were recorded on Applied Biosystems 4800 Maldi TOF/TOF Analyzer (Supporting Information File 1, Figures S6–S9). Mechanochemical reactions were carried out using an IST500 (InSolido Tehnologies, Croatia) mixer mill

p-tert-Butylthiacalix[4]arenes functionalized by N-(4’-nitrophenyl)acetamide and N,N-diethylacetamide fragments: synthesis and binding of anionic guests

• Alena A. Vavilova and
• Ivan I. Stoikov

Beilstein J. Org. Chem. 2017, 13, 1940–1949, doi:10.3762/bjoc.13.188

• conformation was obtained with 10% yield (Scheme 1). 1Н, 13С, 2D NOESY NMR, IR spectroscopy, mass spectrometry (MALDI–TOF) confirmed the macrocycle 3 structure. The elemental analysis gives us the composition of 3. In contrast to the 1H NMR spectrum of 1,3-disubstituted thiacalix[4]arene 2 [42], the signals of

• complete substitution of the initial macrocycle 1. In the MALDI–TOF mass spectrum of the compound 3 (M(C72H72N8O16S4) = 1432.4), a molecular ion peak with Na+ cation (m/z (M + Na+) = 1455.5) was observed (see Supporting Information File 1, Figure S4). p-tert-Butylthiacalix[4]arenes monosubstituted at the

An efficient Pd–NHC catalyst system in situ generated from Na₂PdCl₄ and PEG-functionalized imidazolium salts for Mizoroki–Heck reactions in water

• Nan Sun,
• Meng Chen,
• Liqun Jin,
• Wei Zhao,
• Baoxiang Hu,
• Zhenlu Shen and
• Xinquan Hu

Beilstein J. Org. Chem. 2017, 13, 1735–1744, doi:10.3762/bjoc.13.168

• characterized by 1H NMR, 13C NMR and MALDI–TOF–MS analyses (see Supporting Information File 1). The catalytic performance of the synthesized imidazolium salts as NHC precursors for Pd-catalyzed Mizoroki–Heck reactions in water was investigated. A model reaction was carried out by using 4-bromoacetophenone (1a

• standard. Mass spectrometry data (MALDI–TOF) of the three imidazolium salts L1–L3 were collected on a Bruker ultrafleXtreme mass spectrometer. Low-resolution mass analyses were performed on a Thermo Trace ISQ GC–MS instrument in EI mode (70 eV) or a Thermo Scientific ITQ 1100TM mass spectrometer in ESI

• , NCH2), 3.66–3.42 (m, 196H, CH2 of PEG chain), 3.24 (s, 3H, PEG-OCH3); 13C NMR (CDCl3) δ 153.7, 149.6, 137.6, 137.3, 123.7, 123.0, 122.9, 122.7, 71.2–68.3 (CPEG), 58.1, 53.0, 49.0; MALDI–TOF–MS m/z: [Mn=49 − Br]+ calcd for C110H212N3O50, 2375.4; found, 2375.8. Imidazolium salt L2. Yield: 3.9 g (92

2-Methyl-2,4-pentanediol (MPD) boosts as detergent-substitute the performance of ß-barrel hybrid catalyst for phenylacetylene polymerization

• Julia Kinzel,
• Daniel F. Sauer,
• Marco Bocola,
• Marcus Arlt,
• Tayebeh Mirzaei Garakani,
• Andreas Thiel,
• Klaus Beckerle,
• Tino Polen,
• Jun Okuda and
• Ulrich Schwaneberg

Beilstein J. Org. Chem. 2017, 13, 1498–1506, doi:10.3762/bjoc.13.148

• analyzed by MALDI–TOF mass spectrometry prior to digestion of 2 with the protease of the Tobacco Etch Virus (TEV) [29][47][49]. Even though the calculated mass of 6,301 Da for the FhuA ΔCVFtev fragment containing Cys545 and the metal catalyst (≈6 kDa) could not be observed, the MALDI–TOF mass spectra

• -d1 was dried over calcium hydride, distilled, degassed and stored in a glove box. NMR spectra were recorded on a Bruker DRX 400 spectrometer (1H, 400.1 MHz). Chemical shifts were referenced internally by using the residual solvent resonances [50]. MALDI–TOF MS spectra were recorded on an Ultraflex

• of FhuA ΔCVFtev with MALDI–TOF mass spectrometry, two cleavage sites of the TEV protease (ENLYFQ|G) were introduced in the extracellular loop regions 7 and 8 [29]. Protease cleavage was performed as described previously [12][29]. MD simulations Simulations were based on the X-ray crystal structure of

Mechanochemistry-assisted synthesis of hierarchical porous carbons applied as supercapacitors

• Desirée Leistenschneider,
• Nicolas Jäckel,
• Felix Hippauf,
• Volker Presser and
• Lars Borchardt

Beilstein J. Org. Chem. 2017, 13, 1332–1341, doi:10.3762/bjoc.13.130

• −1 indicates complexation [51]. The sample Polymer-SF-3 was investigated by matrix-assisted laser desorption/ionization with a time-of-flight mass spectrometer (MALDI–TOF) revealing a weight-averaged molar mass (Mw) of 2015.6 g mol−1, which is equivalent to 6 monomeric units. Synthesis of the

Sugar-based micro/mesoporous hypercross-linked polymers with in situ embedded silver nanoparticles for catalytic reduction

• Qing Yin,
• Qi Chen,
• Li-Can Lu and
• Bao-Hang Han

Beilstein J. Org. Chem. 2017, 13, 1212–1221, doi:10.3762/bjoc.13.120

• structures of Sug-2 and Sug-3 have been characterized by 1H NMR, 13C NMR, and MALDI–TOF MS. The chemical structure of the obtained polymers was confirmed by 13C CP/MAS NMR and Fourier transform infrared spectroscopy (FTIR) (Figure S1, Supporting Information File 1). For example, the backbone and structure

• –6.97 (m, 3H), 5.12–4.90 (m, 3H), 4.84 (t, J = 11.1 Hz, 3H), 4.65–4.48 (m, 3H), 3.73 (m, 6H); 13C NMR (100 MHz, CDCl3) δ (ppm) 157.4, 138.6, 138.3, 138.2, 138.1, 129.6, 128.5, 128.4, 128.3, 128.0, 127.9, 127.8, 127.7, 127.6, 122.7, 116.9, 101.7, 84.7, 82.1, 77.8, 75.8, 75.2, 75.1, 73.5, 68.9; MS (MALDI

• ), 3.87–3.70 (m, 2H), 3.61 (dd, J = 18.9, 9.9 Hz, 2H), 3.26 (s, 3H), 1.38–1.26 (m, 3H); 13C NMR (100 MHz, CDCl3) δ (ppm) 138.8, 138.7, 138.5, 128.5, 128.1, 128.0, 127.8, 127.7, 127.6, 99.2, 80.6, 80.3, 75.5, 74.9, 72.9, 72.2, 68.0, 54.7, 18.1; MS (MALDI–TOF) m/z: [M + Na] calcd for C28H32O5, 471.2; found

Interactions between shape-persistent macromolecules as probed by AFM

• Johanna Blass,
• Jessica Brunke,
• Franziska Emmerich,
• Cédric Przybylski,
• Vasil M. Garamus,
• Artem Feoktystov,
• Roland Bennewitz,
• Gerhard Wenz and
• Marcel Albrecht

Beilstein J. Org. Chem. 2017, 13, 938–951, doi:10.3762/bjoc.13.95

• end groups were prepared starting from diacetylene-modified cyclodextrin monomers by a combined Glaser coupling/click chemistry approach. Structural perfection of the neutral CD polymers and inclusion complex formation with ditopic and monotopic guest molecules were proven by MALDI–TOF and UV–vis

• characteristic bathochromic shift could be observed both in the absorption and emission spectra of polymer 8 (Figure 3) showing the presence of the extended polyconjugated π-system. Quantitative information about the molecular weight distribution of 8 was obtained by MALDI–TOF measurements using an ionic liquid

• matrix (HABA/TMG2) [55]. A representative MALDI spectrum, shown in Figure 4, exhibits a wide range of broad signals starting from the signal of the dimer at m/z 2,621.33 Da detected as [M + Na]+ and ending at the 38mer at m/z 48,196.23 Da for a S/N ratio ≥3, with an average 1297.4 mass units shift

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

• -day infection by flow cytometry and fluorescence microscopy to determine the cell surface expression of the GAT1/GFP fusion proteins. MALDI mass fingerprinting Using MALDI–TOF MS, protein fragments with blocked N-termini or that are available in limited concentrations can be easily analyzed. The MALDI

• Blue staining of the GAT1/GFP protein from infected Sf9 cells after immunoprecipitation. Bands a and b (indicated by arrows) were extracted for MALDI–TOF analysis. (B) Mass spectrum of the trypsin digest of band a. The labeled peaks were assigned to either GAT or GFP. Isolation of the GAT1/GFP fusion

Cyclodextrins tethered with oligolactides – green synthesis and structural assessment

• Cristian Peptu,
• Mihaela Balan-Porcarasu,
• Alena Šišková,
• Ľudovít Škultéty and
• Jaroslav Mosnáček

Beilstein J. Org. Chem. 2017, 13, 779–792, doi:10.3762/bjoc.13.77

• ionization like matrix-assisted laser desorption ionization (MALDI) and electrospray ionization (ESI). Liquid chromatography (LC) separation with evaporative light scattering detection (ELSD) and NMR analysis were employed in order to elucidate the structural profiles of the obtained mixtures. The results

• chromatography; L-lactide; MALDI; mass spectrometry; NMR; Introduction Cyclodextrin derivatives are increasingly important and their variety is dictated by the wide range of applications in which these compounds are employed with preponderance in the pharmaceutical field [1][2]. The employed strategies for the

• not asses their products whether these were CD-VL, CD-LA or CD-VL/LA covalent conjugates [19][20]. The results presented by the Harada group generally evaluated the CD-oligoester samples by matrix-assisted laser desorption ionization mass spectrometry (MALDI–MS) and nuclear magnetic resonance (NMR

Fluorescent carbon dots from mono- and polysaccharides: synthesis, properties and applications

• Stephen Hill and
• M. Carmen Galan

Beilstein J. Org. Chem. 2017, 13, 675–693, doi:10.3762/bjoc.13.67

• as the major component in the preparation of this type of CD, as evidenced by 1H, 13C NMR, FTIR and MALDI–MS (Scheme 19). The authors proposed that initial acid catalysed degradation of the sucrose disaccharide to its monosaccharide constituents fructose and glucose, followed by glucose isomerisation

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

A postsynthetically 2’-“clickable” uridine with arabino configuration and its application for fluorescent labeling and imaging of DNA

• Heidi-Kristin Walter,
• Bettina Olshausen,
• Ute Schepers and
• Hans-Achim Wagenknecht

Beilstein J. Org. Chem. 2017, 13, 127–137, doi:10.3762/bjoc.13.16

• modified oligonucleotides were purified by ethanol precipitation in the presence of EDTA to remove copper ions and subsequently by semi-preparative HPLC. Finally, the modified oligonucleotides were identified by MALDI–TOF mass spectrometry (see Supporting Information File 1) and annealed with the

• -10AT, controller SCL-10A, diode array detector SPD-M10A). Purification was confirmed by MS (MALDI–TOF) on a Biflex-IV spectrometer from Bruker Daltonics in the linear negative mode (matrix: 1:9 mixture of diammonium hydrogencitrate (100 g/L) and a saturated 3-hydroxypicolinic acid solution (10 g/L in