Halogen-containing thiazole orange analogues – new fluorogenic DNA stains

• Aleksey A. Vasilev,
• Meglena I. Kandinska,
• Stanimir S. Stoyanov,
• Stanislava B. Yordanova,
• David Sucunza,
• Juan J. Vaquero,
• Obis D. Castaño,
• Stanislav Baluschev and
• Silvia E. Angelova

Beilstein J. Org. Chem. 2017, 13, 2902–2914, doi:10.3762/bjoc.13.283

• and the fluorescence spectra on a Cary Eclipse fluorescence spectrophotometer (Varian, Australia). The GC–MS analysis was performed on a gas chromatograph HP 6890 GC System Plus coupled to a mass selective detector HP 5973 MSD. The mass selective detector operated in electron impact ionization mode at

Binding abilities of polyaminocyclodextrins: polarimetric investigations and biological assays

• Marco Russo,
• Daniele La Corte,
• Annalisa Pisciotta,
• Serena Riela,
• Rosa Alduina and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2017, 13, 2751–2763, doi:10.3762/bjoc.13.271

• were isolated and purified by repeated precipitations from ethanol/diethyl ether. The characterization was carried out by means of potentiometric acid–base titration, which confirmed that the ionization behaviour of the AmCDs can be modelled as a mixture of four independent virtual weak bases. The

Syntheses, structures, and stabilities of aliphatic and aromatic fluorous iodine(I) and iodine(III) compounds: the role of iodine Lewis basicity

• Tathagata Mukherjee,
• Soumik Biswas,
• Andreas Ehnbom,
• Subrata K. Ghosh,
• Ibrahim El-Zoghbi,
• Nattamai Bhuvanesh,
• Hassan S. Bazzi and
• John A. Gladysz

Beilstein J. Org. Chem. 2017, 13, 2486–2501, doi:10.3762/bjoc.13.246

• than 0.5 kcal/mol. In all cases, vertical ionization potentials (not presented) followed analogous trends. The iodine(III) dichlorides formed in the more exergonic reactions (upper portion of Figure 4) would be expected to be more stable with respect to Cl2 evolution. Thus, the data are consistent with

Herpetopanone, a diterpene from Herpetosiphon aurantiacus discovered by isotope labeling

• Xinli Pan,
• Nicole Domin,
• Sebastian Schieferdecker,
• Hirokazu Kage,
• Martin Roth and
• Markus Nett

Beilstein J. Org. Chem. 2017, 13, 2458–2465, doi:10.3762/bjoc.13.242

• includes α-cadinol, originates from germacrene D [7][23]. In the case of 1, an analogous pathway can be postulated, which is depicted in Figure 4. The biosynthesis would hence start with geranylgeranyl pyrophosphate (GGPP). Upon ionization, the double bond nearest the diphosphate can adopt a Z

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

Is the tungsten(IV) complex (NEt₄)₂[WO(mnt)₂] a functional analogue of acetylene hydratase?

• Matthias Schreyer and
• Lukas Hintermann

Beilstein J. Org. Chem. 2017, 13, 2332–2339, doi:10.3762/bjoc.13.230

• , ionization is brought about without an added reagent, and catalytic activity towards Markovnikov product 5 revealed, even if the conversion is low (Table 1, entry 1). A cyclopentadienylruthenium(II) catalyst with the ambifunctional steering ligand ISIPHOS (2-(diphenylphosphino)-6-(2,4,6-triisopropylphenyl

Comparative profiling of well-defined copper reagents and precursors for the trifluoromethylation of aryl iodides

• Peter T. Kaplan,
• Jessica A. Lloyd,
• Mason T. Chin and
• David A. Vicic

Beilstein J. Org. Chem. 2017, 13, 2297–2303, doi:10.3762/bjoc.13.225

• flame ionization detector (FID). A Rxi-5ms (fused silica), low-polarity phase, crossbond diphenyl dimethyl polysiloxane, 15.0 m length column was used. Parameters were: injection volume of 4.0 µL, 25:1 split ratio, linear velocity of 57.0 cm/s, total flow of 65.3 mL/min, and temperature program starting

New bio-nanocomposites based on iron oxides and polysaccharides applied to oxidation and alkylation reactions

• Daily Rodríguez-Padrón,
• Alina M. Balu,
• Antonio A. Romero and
• Rafael Luque

Beilstein J. Org. Chem. 2017, 13, 1982–1993, doi:10.3762/bjoc.13.194

• injected into a gas chromatograph through a microreactor in which the catalyst was previously sited. The injected base was analyzed by gas chromatography with a flame ionization detector and using an analytical column of 0.5 m length, containing 5 wt % of polyphenylether in the Chromosorb AW-DMCS in 80/100

• chromatograph (60 mL min−1 N2 carrier flow, 20 psi column top head pressure) using a flame ionization detector (FID). A HP-101 capillary column (25 m × 0.2 mm × 0.2 μm) was employed. All calculations were based on the use of benzyl chloride and benzyl alcohol as limiting reagents for the studied alkylation and

An effective Pd nanocatalyst in aqueous media: stilbene synthesis by Mizoroki–Heck coupling reaction under microwave irradiation

• Carolina S. García,
• Paula M. Uberman and
• Sandra E. Martín

Beilstein J. Org. Chem. 2017, 13, 1717–1727, doi:10.3762/bjoc.13.166

• chromatograph with a flame ionization detector, and equipped with the following columns: HP-5 25 m × 0.20 mm × 0.25 μm column. 1H NMR and 13C NMR were conducted on a high resolution spectrometer Bruker Advance 400, in CDCl3 as solvent. Gas chromatographic/mass spectrometer analyses were carried out on a GC–MS

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

• indicate the successful conjugation of the catalyst by an increase of the molecular weight of 116 Da corresponding to the maleimide group (Figure 4). In studies with other catalysts attached to FhuA ΔCVFtev, the addition of water to the maleimide ring was observed [10][47]. During digestion or ionization

Mechanochemical synthesis of graphene oxide-supported transition metal catalysts for the oxidation of isoeugenol to vanillin

• Ana Franco,
• Sudipta De,
• Alina M. Balu,
• Araceli Garcia and
• Rafael Luque

Beilstein J. Org. Chem. 2017, 13, 1439–1445, doi:10.3762/bjoc.13.141

• nm × 0.5 μm and a flame ionization detector (FID). The results were finally confirmed by GC–MS. N2 isotherms of (a) RGO, (b) Fe/RGO, and (c) Co/RGO. SEM images of (a and b) RGO, (c) 1% Fe/RGO, and (d) 1% Co/RGO. TEM micrographs at different magnifications of (a and b) RGO, (c and d) 1% Fe/RGO, and (e

A speedy route to sterically encumbered, benzene-fused derivatives of privileged, naturally occurring hexahydropyrrolo[1,2-b]isoquinoline

• Olga Bakulina,
• Alexander Ivanov,
• Vitalii Suslonov,
• Dmitry Dar’in and
• Mikhail Krasavin

Beilstein J. Org. Chem. 2017, 13, 1413–1424, doi:10.3762/bjoc.13.138

• HRMS-ESI-qTOF spectrometer (electrospray ionization mode). X-ray single crystal analyses were performed with monochromated Mo Kα or Cu Kα radiation, respectively. Column chromatography was performed on silica gel 60 (230–400 mesh). For TLC analysis UV254 silica gel coated plates were used. MeCN was

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

Synthesis and enzymatic ketonization of the 5-(halo)-2-hydroxymuconates and 5-(halo)-2-hydroxy-2,4-pentadienoates

• Tyler M. M. Stack,
• William H. Johnson Jr. and
• Christian P. Whitman

Beilstein J. Org. Chem. 2017, 13, 1022–1031, doi:10.3762/bjoc.13.101

• . Pooled fractions were concentrated and exchanged into 20 mM KH2PO4 buffer (pH 7.3) using an Amicon Ultra filter unit (3K membrane). This procedure typically yields ≈8 mg of 4-OT estimated to be ≈95% pure. A sample was analyzed by electrospray ionization mass spectrometry (ESIMS) to verify the molecular

Use of costic acid, a natural extract from Dittrichia viscosa, for the control of Varroa destructor, a parasite of the European honey bee

• Kalliopi Sofou,
• Demosthenis Isaakidis,
• Apostolos Spyros,
• Anita Büttner,
• Athanassios Giannis and
• Haralambos E. Katerinopoulos

Beilstein J. Org. Chem. 2017, 13, 952–959, doi:10.3762/bjoc.13.96

• best component resolution with a total analysis time of 67 min. The mass unit conditions were: ionization energy 70 eV, ion source 195 °C, with 0.5 scans/s from 35 to 450 m/z. Chromatographs and mass spectra were recorded using the CLASS 5000 program. Components were identified on the basis of their

Conformational study of L-methionine and L-cysteine derivatives through quantum chemical calculations and ³J_HH coupling constant analyses

• Weslley G. D. P. Silva,
• Carolyne B. Braga and
• Roberto Rittner

Beilstein J. Org. Chem. 2017, 13, 925–937, doi:10.3762/bjoc.13.94

• happens in the biological environment. The conformers of L-Met and L-Cys have been investigated by several experimental and theoretical methodologies, including FTIR [11], rotational and IR−UV double resonance spectroscopies [12][13], photon ionization mass spectrometry [14], X-ray absorption [15] and

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

• mass fingerprinting was performed by Dr. Chris Weise (Free University Berlin, Germany) with a Bruker-Biflex Reflex Mass spectrometer (Bruker Daltonics) in the reflector-mode with alpha-cyano-4-hydroxycinnamic acid as matrix. Ionization was enhanced with the 337 nm-ray of a nitrogen laser. The peptide

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

• 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

• conjugates were evaluated in view of the products relative content only based on the MALDI–MS spectra. Generally, compounds with different ionization efficiency in MALDI–MS will give different MS response or intensity of the corresponding MS peaks [27] which does not allow a precise quantitative measurement

Novel β-cyclodextrin–eosin conjugates

• Gábor Benkovics,
• Damien Afonso,
• András Darcsi,
• Szabolcs Béni,
• Sabrina Conoci,
• Éva Fenyvesi,
• Lajos Szente,
• Milo Malanga and
• Salvatore Sortino

Beilstein J. Org. Chem. 2017, 13, 543–551, doi:10.3762/bjoc.13.52

• protons unambiguously confirms the monosubstitution pattern (DS = 1) in both cases and was further proven by electrospray ionization mass spectrometry (ESIMS) analysis of the compounds (see Supporting Information File 1). The signals in the aromatic region are well resolved (see Figures S25 and S33

Decarboxylative and dehydrative coupling of dienoic acids and pentadienyl alcohols to form 1,3,6,8-tetraenes

• Ghina’a I. Abu Deiab,
• Mohammed H. Al-Huniti,
• I. F. Dempsey Hyatt,
• Emma E. Nagy,
• Kristen E. Gettys,
• Sommayah S. Sayed,
• Christine M. Joliat,
• Paige E. Daniel,
• Rupa M. Vummalaneni,
• Andrew T. Morehead Jr,
• Andrew L. Sargent and
• Mitchell P. Croatt

Beilstein J. Org. Chem. 2017, 13, 384–392, doi:10.3762/bjoc.13.41

• additional evidence of product inhibition). The isomerization reaction to form 22 was presumably occurring via ionization of the allylic system using Pd(0), followed by recombination of the carboxylate at the terminal position of the pentadienyl system. Based on these data, we hypothesized that a two

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

• Chemistry (KIT) using a Finnigan MAT95 in positive ionization mode. NMR spectra were recorded on a Bruker B-ACS-60, Bruker Avance DRX 400 and a Bruker Avance DRX 500 spectrometer in deuterated solvents (1H at 300, 400 or 500 MHz, 13C at 75, 100 or 125 MHz). Chemical shifts are given in ppm relative to TMS

Synthesis and evaluation of anti-oxidant and cytotoxic activities of novel 10-undecenoic acid methyl ester based lipoconjugates of phenolic acids

• Naganna Narra,
• Shiva Shanker Kaki,
• Rachapudi Badari Narayana Prasad,
• Sunil Misra,
• Koude Dhevendar,
• Venkateshwarlu Kontham and
• Padmaja V. Korlipara

Beilstein J. Org. Chem. 2017, 13, 26–32, doi:10.3762/bjoc.13.4

• , respectively. Coupling constants (J) patterns in the 1H NMR spectra are given as follows: s = singlet, d = doublet, t = triplet, q = quartet, m = multiplet protons. Mass spectra were recorded using electron spray ionization (ESI) on a Waters e2695 Separators module (Waters, Milford, MA, USA) mass spectrometer

• molecules were determined with a capillary tube melting point apparatus. Gas chromatography (GC) was performed on an Agilent 6890N gas chromatograph (Delaware, USA) equipped with a flame ionization detector using a HP-1 capillary column (30 m × 0.25 mm × 0.25 μm). The injector and detector temperatures were

New approaches to organocatalysis based on C–H and C–X bonding for electrophilic substrate activation

• Pavel Nagorny and
• Zhankui Sun

Beilstein J. Org. Chem. 2016, 12, 2834–2848, doi:10.3762/bjoc.12.283

• without significant erosion in yield or reaction time [55]. Interestingly, the ability of catalysts L13 to catalyze the reaction was attributed to 1-chloroisochroman activation through Coulombic interactions coupled with anion–π bonding. Thus, L13 was proposed to promote ionization of 1-chloroisochroman

• propose that catalysts L13 could act not only through Coulombic interactions, but also as hydrogen bond donors. While various factors including Coulombic interactions between the pyridinium (or ammonium) salt and the chloride undoubtedly play an important role in promoting substrate ionization and

Identification, synthesis and mass spectrometry of a macrolide from the African reed frog Hyperolius cinnamomeoventris

• Markus Menke,
• Pardha Saradhi Peram,
• Iris Starnberger,
• Walter Hödl,
• Gregory F.M. Jongsma,
• David C. Blackburn,
• Mark-Oliver Rödel,
• Miguel Vences and
• Stefan Schulz

Beilstein J. Org. Chem. 2016, 12, 2731–2738, doi:10.3762/bjoc.12.269

• present in 1 is shifted to m/z 182 in 2. These ions can be used to assign the location of the double bond in the macrocyclic ring. A possible fragmentation pathway leading to these ions is shown in Figure 5. One can speculate that after ionization of the double bond in 1 an allylic cleavage occurs

• location of the double bond at C-9 (Figure 5). A b-type ion cannot be formed, because pathway b is not operative due to the close proximity of the C–O group. The pathways shown in Figure 5 are speculative. Another possible mechanisms leading to the same ions and starting with ionization of the C–O oxygen