The effect of permodified cyclodextrins encapsulation on the photophysical properties of a polyfluorene with randomly distributed electron-donor and rotaxane electron-acceptor units

• Aurica Farcas,
• Ana-Maria Resmerita,
• Pierre-Henri Aubert,
• Flavian Farcas,
• Iuliana Stoica and
• Anton Airinei

Beilstein J. Org. Chem. 2014, 10, 2145–2156, doi:10.3762/bjoc.10.222

• Vertex 70 spectrophotometer. The molecular weights of copolymers were determined by GPC in THF by using a Water Associates 440 instrument and polystyrene (Pst) calibrating standards. TGA analysis was performed under a constant flow of nitrogen (20 mL·min−1) with a heating rate of 10 °C·min−1 and using a

Synthesis and bioactivity of analogues of the marine antibiotic tropodithietic acid

• Patrick Rabe,
• Tim A. Klapschinski,
• Nelson L. Brock,
• Christian A. Citron,
• Paul D’Alvise,
• Lone Gram and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2014, 10, 1796–1801, doi:10.3762/bjoc.10.188

• . 297963, Becton, Dickinson and Company, Sparks, MD, USA). The minimum inhibitory concentration (MIC) of the compounds was determined using the microdilution method according to the guidelines of the Clinical and Laboratory Standards Institute (CLSI 2006) [21]. All compounds were dissolved in DMSO to stock

Copolymerization and terpolymerization of carbon dioxide/propylene oxide/phthalic anhydride using a (salen)Co(III) complex tethering four quaternary ammonium salts

• Jong Yeob Jeon,
• Seong Chan Eo,
• Jobi Kodiyan Varghese and
• Bun Yeoul Lee

Beilstein J. Org. Chem. 2014, 10, 1787–1795, doi:10.3762/bjoc.10.187

• using a Waters Millennium apparatus with polystyrene standards. The Tg data were determined from a second heating at a heating rate of 10 °C/min by differential scanning calorimetry (DSC) using a Thermal Analysis Q10 instrument. Typical procedure for PO/PA alternating copolymerizations. A bomb reactor

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

• 6.0) and fluorescent microsphere standards (Dragon Green, Bangs Laboratories, Inc.) provided similar diameters as those obtained in DLS experiments (Figure 3, Table 1). The polydispersity calculated from the micrographs (Figure 4) was higher than that calculated by DLS, but this is likely due to

• standards were purchased from Bangs Laboratories, Inc.. Dichloromethane was purified on basic alumina; other solvents were used as received. Silica gel (32–63 μm “40 micron flash”) for flash column chromatography purification was purchased from Scientific Adsorbants Incorporated. 5-Isothiocyanato-3

• . Spectra of all-functionalized dendrimers were obtained using a trans-3-indolacrylic acid matrix with a matrix:analyte ratio of 3000:1 or 1000:1. Bovine serum albumin (Mw 66,431 g/mol), cytochrome C (Mw 12,361 g/mol), and trypsinogen (Mw 23,982 g/mol) were used as external standards. An aliquot

Streptopyridines, volatile pyridine alkaloids produced by Streptomyces sp. FORM5

• Ulrike Groenhagen,
• Michael Maczka,
• Jeroen S. Dickschat and
• Stefan Schulz

Beilstein J. Org. Chem. 2014, 10, 1421–1432, doi:10.3762/bjoc.10.146

• series of n-alkanes (C8–C32). Compounds were identified by comparison of mass spectra to database spectra (Wiley 7, NIST 08 and our own created from synthesized reference compounds), by comparison of the retention index data to standards (own database and NIST Chemistry WebBook (2013) [14]) and by

Heronapyrrole D: A case of co-inspiration of natural product biosynthesis, total synthesis and biodiscovery

• Jens Schmidt,
• Zeinab Khalil,
• Robert J. Capon and
• Christian B. W. Stark

Beilstein J. Org. Chem. 2014, 10, 1228–1232, doi:10.3762/bjoc.10.121

• (±) (Zorbax C8, gradient elution 90% to 10% H2O/MeCN with a constant 0.05% formic acid modifier). This analysis, supported by co-injection with authentic natural product standards, confirmed the presence of heronapyrroles A–C, and also detected an unidentified peak exhibiting the characteristic heronapyrrole

N-Alkylated dinitrones from isosorbide as cross-linkers for unsaturated bio-based polyesters

• Oliver Goerz and
• Helmut Ritter

Beilstein J. Org. Chem. 2014, 10, 902–909, doi:10.3762/bjoc.10.88

• used. A set of columns packed with porous styrene–divinylbenzene–copolymer beads was used for the separation of the analytes (MZ Analysentechnik GmbH, 1 × guard column 100 Å, 3 × columns with 10.000, 1000 und 100 Å). The system was calibrated with polystyrene standards with a molecular range from 575 g

Synthesis and biological activity of N-substituted-tetrahydro-γ-carbolines containing peptide residues

• Nadezhda V. Sokolova,
• Valentine G. Nenajdenko,
• Vladimir B. Sokolov,
• Daria V. Vinogradova,
• Elena F. Shevtsova,
• Ludmila G. Dubova and
• Sergey O. Bachurin

Beilstein J. Org. Chem. 2014, 10, 155–162, doi:10.3762/bjoc.10.13

• corresponding dihydrochloride salts 7a–g in nearly quantitative yields (Scheme 4). The final dihydrochloride salts 7a–g were tested on rat liver mitochondria (RLM) using standards tests: lipid peroxidation (LP), mitochondrial membrane potential (ΔΨm) and Ca2+-induced mitochondrial permeability transition (MPT

Silica: An efficient catalyst for one-pot regioselective synthesis of dithioethers

• Samir Kundu,
• Babli Roy and
• Basudeb Basu

Beilstein J. Org. Chem. 2014, 10, 26–33, doi:10.3762/bjoc.10.5

• NMR spectra and residual solvent signals for 13C NMR spectra as internal standards. Coupling constants (J) are reported in Hertz (Hz). Standard abbreviations indicating multiplicity were used as follows: s = singlet, d = doublet, t = triplet, q = quartet, qnt = quintet, m = multiplet. Melting points

Synthesis of nucleotide–amino acid conjugates designed for photo-CIDNP experiments by a phosphotriester approach

• Tatyana V. Abramova,
• Olga B. Morozova,
• Vladimir N. Silnikov and
• Alexandra V. Yurkovskaya

Beilstein J. Org. Chem. 2013, 9, 2898–2909, doi:10.3762/bjoc.9.326

• standards, the use of the hyperpolarization approach is extraordinary to elucidate the interactions between hidden transient intermediates of nucleosides and amino acids in conjugates, which mimic biologically relevant processes. The liquid phase synthesis (LPS) in combination with the phosphotriester

• appropriate deuterated solvents at 30 °C. Chemical shifts (δ) are reported in ppm relative to the TMS signal. In the case of 31P and 19F, external standards of 85% H3PO4 and C6F6, respectively, were used. Coupling constants J are reported in Hertz. Mass spectra were registered in The Center of Cooperative Use

Continuous-flow Heck synthesis of 4-methoxybiphenyl and methyl 4-methoxycinnamate in supercritical carbon dioxide expanded solvent solutions

• Phei Li Lau,
• Ray W. K. Allen and
• Peter Styring

Beilstein J. Org. Chem. 2013, 9, 2886–2897, doi:10.3762/bjoc.9.325

• . After this digestion period, the sample was left to cool and quantitatively transferred to a 50 mL tube and topped up to 50 mL with 1% nitric acid. The element of interest (palladium) was measured against a calibrated sample prepared from known standards. The sample was introduced to the instrument

• containing the mixture of products. The samples were then analysed by gas chromatography (GC) and GC-mass spectrometry (GC–MS) against known calibration standards of the starting material and products. At the end of reaction, the system tubing and reactor were flushed with CO2 and the organic solvent mixture

[²H₂₆]-1-epi-Cubenol, a completely deuterated natural product from Streptomyces griseus

• Christian A. Citron and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2013, 9, 2841–2845, doi:10.3762/bjoc.9.319

• full structure of the natural product [6]. A drawback is the health risk emanating from radioactively labelled compounds, thus requiring high safety standards in their handling. Feeding experiments are today in most cases performed with stable isotopes [7]. For 13C-labelled compounds the locus of

Halogenated volatiles from the fungus Geniculosporium and the actinomycete Streptomyces chartreusis

• Tao Wang,
• Patrick Rabe,
• Christian A. Citron and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2013, 9, 2767–2777, doi:10.3762/bjoc.9.311

• authentic standards of all possible structural isomers was pursued. The six constitutional isomers of a chlorodimethoxybenzene 4a–4f as candidate structures for X are summarised in Figure 3. Compounds 4d and 4e were commercially available, while the remaining isomers were obtained by synthesis according to

Gold(I)-catalyzed hydroarylation reaction of aryl (3-iodoprop-2-yn-1-yl) ethers: synthesis of 3-iodo-2H-chromene derivatives

• Pablo Morán-Poladura,
• Eduardo Rubio and
• José M. González

Beilstein J. Org. Chem. 2013, 9, 2120–2128, doi:10.3762/bjoc.9.249

• Bruker DPX-300, or Bruker AVANCE-300 MHz and 400 MHz instruments, with CHCl3 (δ = 7.26, 1H NMR; δ = 77.16, 13C NMR), CH2Cl2 (δ = 5.33, 1H NMR; δ = 54.84, 13C NMR) or DMSO (δ = 2.50, 1H NMR; δ = 39.52, 13C NMR) as internal standards. Data are reported as follows: chemical shift, multiplicity (s: singlet

Synthesis and antibacterial activity of monocyclic 3-carboxamide tetramic acids

• Yong-Chul Jeong and
• Mark G. Moloney

Beilstein J. Org. Chem. 2013, 9, 1899–1906, doi:10.3762/bjoc.9.224

• )] under VG method, the hydrogen-bond donor count, the hydrogen-bond acceptor count, and the rotatable bond count. Antibacterial activity. Antibiotic activity was measured by using standard methodology (Clinical and Laboratory Standards Institute. Methods for antimicrobial susceptibility test for bacteria

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

• derivatives of appropriate standards) enabled us to determine the configuration of the chiral amino acid residues as L-MeAla, D-Leu (×2), D-MeLeu, L-Thr, L-Me-Val, L-Me-Ile, D-Me-allo-Ile, D-Val and L-Val. This result left the ambiguity on the localization of the two methylisoleucine residues and of the two

• retention times (min) of the FDAA standards were 18.15 for L-Thr, 21.50 for L-MeAla, 29.91 for l-Val, 34.04 for L-MeVal, 34.23 for D-Val, 38.25 for L-MeIle, 34.42 for D-MeVal, 41.35 for D-allo-MeIle, 43.20 for D-Leu, 45.08 for D-MeLeu. Observed amino acids and their retention times (min) for FDAA

Organotellurium-mediated living radical polymerization under photoirradiation by a low-intensity light-emitting diode

• Yasuyuki Nakamura and
• Shigeru Yamago

Beilstein J. Org. Chem. 2013, 9, 1607–1612, doi:10.3762/bjoc.9.183

• eluent. The number-average molecular weight (Mn) is reported in g·mol−1. PMMA and poly(methyl acrylate) were calibrated with PMMA standards, and polystyrene was calibrated with polystyrene standards. Materials: Unless otherwise noted, chemicals obtained from commercial suppliers were used as received

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

• porosity of 0.2 µm. The column oven was kept at 40 °C, and the injection volume was 20 µL. One ResiPore Pre-column (50 mm, 4.6 mm) and two ResiPore columns (250 mm, 4.9 mm) from Polymer Laboratories were used in series. The system was calibrated by using polystyrene standards in the range 100–400,000 g·mol

• molecule (C32H61NO18P+, m/ztheo 778.3621) was accurately mass measured with a relative error of ±0.3 ppm by using two reference ions from a poly(propylene glycol) as internal standards. Nitroxide-mediated polymerization of styrene in N,N-dimethylacetamide After the addition of styrene (2.16 g, 20.7 mmol

Controlled synthesis of poly(3-hexylthiophene) in continuous flow

• Helga Seyler,
• Jegadesan Subbiah,
• David J. Jones,
• Andrew B. Holmes and
• Wallace W. H. Wong

Beilstein J. Org. Chem. 2013, 9, 1492–1500, doi:10.3762/bjoc.9.170

• reagent concentrations (Table 1). Gel-permeation chromatography (GPC) analysis in toluene (against polystyrene standards) revealed the formation of polymer with number-average molecular weights (Mn) ranging from 5 to 40 kg/mol. The Mn values increased linearly with nickel catalyst content, providing

• toluene as the eluent and calibrated against polystyrene reference standards. Materials: 2,5-Dibromo-3-hexylthiophene [27], 2-bromo-5-chloromagnesium-3-hexylthiophene [28], and cis-chloro(2-tolyl)(dppp)nickel(II) complex [8] were prepared according to procedures described in the literature. Commercial

Metal-free aerobic oxidations mediated by N-hydroxyphthalimide. A concise review

• Lucio Melone and
• Carlo Punta

Beilstein J. Org. Chem. 2013, 9, 1296–1310, doi:10.3762/bjoc.9.146

• complexes. However, eco-friendly standards, including the demand for highly selective transformations, impose the development of metal-free processes, especially for large-scale productions, as in the case of the oxygenation of hydrocarbons. For this reason, many efforts have been devoted in the past decade

• detrimental for the selectivity of the process and they would not meet the standards of “green chemistry”. An alternative catalytic route is based on the use of N-hydroxy imides (NHIs), and in particular N-hydroxyphthalimide (NHPI), which have found ample application as ideal catalysts for the aerobic

The synthesis of well-defined poly(vinylbenzyl chloride)-grafted nanoparticles via RAFT polymerization

• John Moraes,
• Kohji Ohno,
• Guillaume Gody,
• Thomas Maschmeyer and
• Sébastien Perrier

Beilstein J. Org. Chem. 2013, 9, 1226–1234, doi:10.3762/bjoc.9.139

• .)) were determined by using a SEC system calibrated with narrow-molecular-weight poly(styrene) standards. Since this system results in Mn(Exp.) values relative to poly(styrene), these Mn(Exp.) were corrected by taking into account the difference in molecular weight between VBC and styrene (see Table 1

Substituent effect on the energy barrier for σ-bond formation from π-single-bonded species, singlet 2,2-dialkoxycyclopentane-1,3-diyls

• Jianhuai Ye,
• Yoshihisa Fujiwara and
• Manabu Abe

Beilstein J. Org. Chem. 2013, 9, 925–933, doi:10.3762/bjoc.9.106

• C6D6 as internal standards. Assignments of 13C NMR were carried out by DEPT measurements. IR spectra were recorded with a FTIR spectrometer. UV–vis spectra were taken by a JASCO V-630 spectrophotometer. Mass-spectrometric data were measured by a Mass Spectrometric Thermo Fisher Scientific LTQ Orbitrap

Chemoenzymatic synthesis and biological evaluation of enantiomerically enriched 1-(β-hydroxypropyl)imidazolium- and triazolium-based ionic liquids

• Paweł Borowiecki,
• Małgorzata Milner-Krawczyk and
• Jan Plenkiewicz

Beilstein J. Org. Chem. 2013, 9, 516–525, doi:10.3762/bjoc.9.56

• enzyme-catalyzed syntheses of acetylated standards were used, since the conventional esterification procedure of (±)-3a and (±)-3b (with Ac2O, pyridine and DMAP) gave low yields (ca. 25%) of the acetates. Determination of the stereochemistry of alcohols (+)-5a and (+)-5b The absolute configurations of

Metal-mediated aminocatalysis provides mild conditions: Enantioselective Michael addition mediated by primary amino catalysts and alkali-metal ions

• Matthias Leven,
• Jörg M. Neudörfl and
• Bernd Goldfuss

Beilstein J. Org. Chem. 2013, 9, 155–165, doi:10.3762/bjoc.9.18

• mixture was subjected to column chromatography without quenching, and all yields were determined as isolated yields. The ee’s were established by chiral HPLC according to racemic standards and literature data [23]. 4-Hydroxy-3-(3-oxo-1-phenylbutyl)coumarin (warfarin). 1H and 13C NMR data were found to be

Influence of cyclodextrin on the solubility and the polymerization of (meth)acrylated Triton^® X-100

• Melanie Kemnitz and
• Helmut Ritter

Beilstein J. Org. Chem. 2012, 8, 2176–2183, doi:10.3762/bjoc.8.245

• /min. For detection a Viscotek VE 3500 RI detector was used. The system was calibrated with polystyrene standards within a molecular range from 575 to 3,114,000 g/mol. On a Mettler Toledo DSC 822 instrument the DSC measurements were determined in a range of −50 to 200 °C at the heating rate of 10 °C