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

• liquid chromatography (RP-HPLC) was performed using two Shimadzu systems each equipped with a CBM-20A communications bus module, two LC-20AT pumps, an SIL-20A auto sampler, an SPD-20A UV–vis detector, a CTO-20A column oven, one with an FRC-10A fraction collector and one without. Matrix-assisted laser

Natural and redesigned wasp venom peptides with selective antitumoral activity

• Marcelo D. T. Torres,
• Gislaine P. Andrade,
• Roseli H. Sato,
• Cibele N. Pedron,
• Tania M. Manieri,
• Giselle Cerchiaro,
• Anderson O. Ribeiro,
• Cesar de la Fuente-Nunez and
• Vani X. Oliveira Jr.

Beilstein J. Org. Chem. 2018, 14, 1693–1703, doi:10.3762/bjoc.14.144

• lyophilized peptides were then purified by preparative reversed-phase high-performance liquid chromatography (RP-HPLC) in 0.1% TFA/90% ACN in water (A/B) on a Delta Prep 600 (Waters Associates). Briefly, the peptides were loaded onto a Phenomenex C18 (21.2 mm × 250 mm, 15 µm particles, 300 Å pores) column at

• a flow rate of 10.0 mL min−1 and eluted using a linear gradient (0.33% B/min slope), with detection at 220 nm. Selected fractions containing the purified peptides were pooled and lyophilized. Purified peptides were characterized by liquid-chromatography electrospray-ionization mass spectrometry (LC

Heterogeneous acidic catalysts for the tetrahydropyranylation of alcohols and phenols in green ethereal solvents

• Ugo Azzena,
• Massimo Carraro,
• Gloria Modugno,
• Luisa Pisano and
• Luigi Urtis

Beilstein J. Org. Chem. 2018, 14, 1655–1659, doi:10.3762/bjoc.14.141

• any decomposition product within the reaction mixtures, as determined by 1H, 13C NMR and gas-liquid chromatography analyses [32]. Due to the ease of the preparation from particularly cheap starting materials, the ease of handling and its high activity, we further investigated the ability of NH4HSO4

Cobalt–metalloid alloys for electrochemical oxidation of 5-hydroxymethylfurfural as an alternative anode reaction in lieu of oxygen evolution during water splitting

• Jonas Weidner,
• Stefan Barwe,
• Kirill Sliozberg,
• Stefan Piontek,
• Justus Masa,
• Ulf-Peter Apfel and
• Wolfgang Schuhmann

Beilstein J. Org. Chem. 2018, 14, 1436–1445, doi:10.3762/bjoc.14.121

• V vs RHE was performed and product analysis at various time points during electrolysis was conducted by means of high-performance liquid chromatography (HPLC) to monitor the oxidation of HMF to FDCA. The current density vs time transient (Supporting Information File 1, Figure S5) shows a rapid

• Faradays were transferred after 60 min of electrolysis further pointing towards complete conversion of HMF. High-performance liquid chromatography product analysis HPLC was employed to qualitatively and quantitatively determine the conversion of HMF and all potential side products. HMF oxidation starts

One hundred years of benzotropone chemistry

• Arif Dastan,
• Haydar Kilic and
• Nurullah Saracoglu

Beilstein J. Org. Chem. 2018, 14, 1120–1180, doi:10.3762/bjoc.14.98

• the thermal and electron impact-induced decarbonylation reaction of 12 (Scheme 36) [131]. Tajiri’s group reported the resolution and determination of the kinetic parameters of the optically active 2,3-benzotropone(tricarbonyl)iron complex 221 using high-performance liquid chromatography (HPLC) and

Synthesis and in vitro biochemical evaluation of oxime bond-linked daunorubicin–GnRH-III conjugates developed for targeted drug delivery

• Sabine Schuster,
• Beáta Biri-Kovács,
• Bálint Szeder,
• Viktor Farkas,
• László Buday,
• Zsuzsanna Szabó,
• Gábor Halmos and
• Gábor Mező

Beilstein J. Org. Chem. 2018, 14, 756–771, doi:10.3762/bjoc.14.64

• of ACN/water (1:1, v/v) and 0.1% formic acid. Liquid chromatography–mass spectrometry (LC–MS) was carried out on the same spectrometer equipped with an Agilent 1100 HPLC system and a diode array detector (Agilent, Waldbronn, Germany). Peptides were separated on a Supelco C18 column (150 mm × 2.1 mm

Heterogeneous Pd catalysts as emulsifiers in Pickering emulsions for integrated multistep synthesis in flow chemistry

• Katharina Hiebler,
• Georg J. Lichtenegger,
• Manuel C. Maier,
• Eun Sung Park,
• Renie Gonzales-Groom,
• Bernard P. Binks and
• Heidrun Gruber-Woelfler

Beilstein J. Org. Chem. 2018, 14, 648–658, doi:10.3762/bjoc.14.52

• monitored by high-performance liquid chromatography (HPLC). In general, the catalysts with tin proportions of 0.20, 0.79 and 0.99 proved to be most effective in the desired transformations with exceptional high activities (turn over frequency, TOF > 12,000 h−1) in all tested Suzuki–Miyaura cross-coupling

High-yielding continuous-flow synthesis of antimalarial drug hydroxychloroquine

• Eric Yu,
• Hari P. R. Mangunuru,
• Nakul S. Telang,
• Caleb J. Kong,
• Jenson Verghese,
• Stanley E. Gilliland III,
• Saeed Ahmad,
• Raymond N. Dominey and
• B. Frank Gupton

Beilstein J. Org. Chem. 2018, 14, 583–592, doi:10.3762/bjoc.14.45

• reaction volume of material (150 mL) had passed through the CSTR indicating that steady-state was reached. The reaction was monitored by liquid chromatography and 1H NMR. The reaction mixture was filtered through a celite pad and dried under reduced pressure. The solution was extracted with water (10 mL

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

• product was dissolved in acetonitrile/water 1:1 and filtered through a Teflon syringe filter. The solution was transferred to a C18 gel column and purified by vacuum liquid chromatography (VLC, 0 to 90% CH3CN in 0.01 M HCl). After lyophilization the product was obtained as a white powder (17 mg, 46%). 1H

• with 1.0 M HCl (aq, 20 μL) and the solvent removed in vacuo. The crude product was dissolved in acetonitrile/water 1:1 and filtered through a Teflon syringe filter. The solution was transferred to a C18 gel column and purified by vacuum liquid chromatography (VLC, 0 to 90% CH3CN in 0.01 M HCl). After

• syringe filter. The solution was transferred to a C18 gel column and purified by vacuum liquid chromatography (VLC, 0 to 90% CH3CN in 0.01 M HCl). After lyophilization the product was obtained as a white powder (11 mg, 31%). 1H NMR (500 MHz, DMSO-d6) δ 7.96 (d, J = 8.3 Hz, 2H), 7.69–7.59 (m, 4H), 7.03 (d

Synthetic and semi-synthetic approaches to unprotected N-glycan oxazolines

• Antony J. Fairbanks

Beilstein J. Org. Chem. 2018, 14, 416–429, doi:10.3762/bjoc.14.30

• also included purification by the use of preparative hydrophilic interaction chromatography–high performance liquid chromatography (HILIC–HPLC), clearly reduces time and effort by removing the need for separation of the yolks and freeze-drying. However, care has to be exercised with respect to the

An efficient synthesis of 1,6-anhydro-N-acetylmuramic acid from N-acetylglucosamine

• Matthew B. Calvert,
• Christoph Mayer and
• Alexander Titz

Beilstein J. Org. Chem. 2017, 13, 2631–2636, doi:10.3762/bjoc.13.261

• molybdate solution (0.02 M solution of ammonium cerium sulfate dihydrate and ammonium molybdate tetrahydrate in 10% aqueous H2SO4) were used for development. Preparative medium pressure liquid chromatography (MPLC) was performed on a Teledyne Isco Combiflash Rf200 system using pre-packed silica gel 60

• , and NOESY experiments. Mass spectra were obtained on a Bruker amaZon SL for low resolution or on a Bruker maXis 4G HR-QTOF spectrometer for high resolution, and the data were analyzed using DataAnalysis (Bruker Daltonics, Bremen, Germany). High-pressure liquid chromatography (HPLC) was carried out on

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

• column chromatography over Polygoprep C18 (Macherey-Nagel) using an increasing concentration of MeOH in water. Fractions containing 1 were identified by LC–MS analysis, pooled and purified by reversed-phase HPLC on a Shimadzu UFLC liquid chromatography system equipped with a Nucleodur C18 HTec column (VP

Aggregation behaviour of a single-chain, phenylene-modified bolalipid and its miscibility with classical phospholipids

• Simon Drescher,
• Vasil M. Garamus,
• Christopher J. Garvey,
• Annette Meister and
• Alfred Blume

Beilstein J. Org. Chem. 2017, 13, 995–1007, doi:10.3762/bjoc.13.99

• -butylammonium fluoride (TBAF) as solvent as well as 1,4-dibromobenzene and octadec-17-yn-1-ol (Ac-C16-OH) [32][39] as starting material. Following, both triple bonds were converted into single bonds by hydrogenation. The bolalipid was finally purified by middle pressure liquid chromatography (MPLC) using CHCl3

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 size-exclusion fast protein liquid chromatography (SE-FPLC). A yield of 200–300 μg of the GAT1/GFP protein could be purified from 400–600 mL of infected Sf9 cells. The purified protein was analyzed by transmission electron microscopy (TEM), which revealed that the GAT1/GFP fusion protein was

• . Subsequently, eluted fractions containing the GAT1/GFP protein were pooled and subjected to fast protein liquid chromatography based on SE (SE-FPLC) with a Superdex 200TM column to obtain purified homogeneous GAT1/GFP fusion protein. To isolate the GAT1/GFP protein from the monoclonal anti-GFP antibody (mAb

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

• thoroughly evaluated by various analytical methods, such as mass spectrometry, NMR spectroscopy and reversed-phase liquid chromatography. Results for particular cyclodextrins (α-, β- and γ-) are compared in order to understand the influence of type of CD on the course of modification. Results and Discussion

• spectroscopy. Liquid chromatography and tandem MS fragmentation studies [21][22][23] are also important additions in deeper structural characterization of CD-oligoester conjugates. The L-LA was reacted with α-, β- and γ-CD (Scheme 1) in bulk at 110 °C in order to ensure a good dispersion of reactants. The

Secondary metabolome and its defensive role in the aeolidoidean Phyllodesmium longicirrum, (Gastropoda, Heterobranchia, Nudibranchia)

• Alexander Bogdanov,
• Cora Hertzer,
• Stefan Kehraus,
• Samuel Nietzer,
• Sven Rohde,
• Peter J. Schupp,
• Heike Wägele and
• Gabriele M. König

Beilstein J. Org. Chem. 2017, 13, 502–519, doi:10.3762/bjoc.13.50

• feeding deterrent activity of the major metabolites 10 and 12. Results UPLC–HRMS metabolome analysis From the ethanolic extract of P. longicirrum the ethyl acetate-soluble organic compounds were analyzed. A first fractionation was achieved by vacuum liquid chromatography (VLC) on reversed-phase material

• with the MeOH extract (3 × 150 mL) of the slug biomass and the solvents were evaporated. After liquid–liquid separation of the methanolic crude extract (4.5 g) between 100 mL H2O and 3 × 100 mL ethyl acetate (EtOAc), EtOAc solubles (2.2 g) were fractionated by vacuum liquid chromatography (VLC) over

Solid-phase enrichment and analysis of electrophilic natural products

• Frank Wesche,
• Yue He and
• Helge B. Bode

Beilstein J. Org. Chem. 2017, 13, 405–409, doi:10.3762/bjoc.13.43

• dehydroalanine [6][7], ketones, aldehydes [8][9], carboxylic acids [8][9], amines [8][9][10], thiols [8][9], alcohols [11], epoxides [12], terminal alkynes [13][14] and azides [15] can be targeted to introduce a label. Such labels might increase the visibility in UV or MS detection in liquid chromatography

Polyketide stereocontrol: a study in chemical biology

• Kira J. Weissman

Beilstein J. Org. Chem. 2017, 13, 348–371, doi:10.3762/bjoc.13.39

• product structures by gas-chromatography/mass spectrometry (GC–MS) and liquid chromatography (LC)–MS. Review Biosynthesis of complex polyketides by modular PKSs and stereochemical considerations The reduced or complex class of polyketides is assembled in bacteria by gigantic multienzymes called polyketide

NMR reaction monitoring in flow synthesis

• M. Victoria Gomez and
• Antonio de la Hoz

Beilstein J. Org. Chem. 2017, 13, 285–300, doi:10.3762/bjoc.13.31

• in which the WET sequence is incorporated into the end of the mix delay. NMR spectroscopy can be coupled to most separation techniques, including gas chromatography (GC), supercritical fluid chromatography (SFC), gel-permeation chromatography (GPC), high-performance liquid chromatography (HPLC

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

3D printed fluidics with embedded analytic functionality for automated reaction optimisation

• Andrew J. Capel,
• Andrew Wright,
• Matthew J. Harding,
• George W. Weaver,
• Yuqi Li,
• Russell A. Harris,
• Steve Edmondson,
• Ruth D. Goodridge and
• Steven D. R. Christie

Beilstein J. Org. Chem. 2017, 13, 111–119, doi:10.3762/bjoc.13.14

• to fully utilise this flexibility, parts were designed which could be integrated with existing flow and analytical instrumentation. An ideal choice for this application is high-performance liquid chromatography (HPLC). HPLC instrumentation is widely available in most modern chemistry laboratories

Formose reaction controlled by boronic acid compounds

• Toru Imai,
• Tomohiro Michitaka and
• Akihito Hashidzume

Beilstein J. Org. Chem. 2016, 12, 2668–2672, doi:10.3762/bjoc.12.263

• recovered by freeze-drying, and characterized by high-performance liquid chromatography (HPLC) using an amino column and a mixed solvent of water and acetonitrile, as can be seen in Figure 2. As reference, this figure also contains an HPLC chart for standard samples, i.e., two-, three-, four-, five-, and

Formose reaction accelerated in aerosol-OT reverse micelles

• Makoto Masaoka,
• Tomohiro Michitaka and
• Akihito Hashidzume

Beilstein J. Org. Chem. 2016, 12, 2663–2667, doi:10.3762/bjoc.12.262

• reverse micelles. However, it was not possible to purify the product because the reaction mixture contained a large amount of AOT. After a large fraction of AOT was removed, the mixture obtained was measured by high-performance liquid chromatography, NMR spectroscopy, and mass spectrometry, but no signals

Methylenelactide: vinyl polymerization and spatial reactivity effects

• Judita Britner and
• Helmut Ritter

Beilstein J. Org. Chem. 2016, 12, 2378–2389, doi:10.3762/bjoc.12.232

• copolymerization parameters of MLA with styrene and MMA, respectively were evaluated through the method of Kelen and Tüdös [18]. For this, the residual monomer ratio was determined by high performance liquid chromatography (see execution, characterization methods and Figures S14 and S15 in Supporting Information

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

• chromatography (HPLC) was conducted with a Hitachi Elite La Chrome HPLC system using CHIRALPAK IA (DAICEL Chemical Industries Ltd.) column with solvent mixtures of ethyl acetate in hexane, 10:90 as eluent for the HPLC experiments at a flow rate of 3 mL/min. Reductive debromination of compound (E)-1B To a