Synthesis, crystal structures and properties of carbazole-based [6]helicenes fused with an azine ring

• Daria I. Tonkoglazova,
• Anna V. Gulevskaya,
• Konstantin A. Chistyakov and
• Olga I. Askalepova

Beilstein J. Org. Chem. 2021, 17, 11–21, doi:10.3762/bjoc.17.2

• reactivity of compounds 9. Its protonation makes the formation of a key cyclization intermediate 11 difficult. It is known that the [n]helicenes with at least one five-membered heteroaromatic ring need n ≥ 6 to become intrinsically chiral [9][10]. High-performance liquid chromatography on chiral stationary

Molecular basis for protein–protein interactions

• Brandon Charles Seychell and
• Tobias Beck

Beilstein J. Org. Chem. 2021, 17, 1–10, doi:10.3762/bjoc.17.1

• analysis software and automation in liquid chromatography–mass spectrometry over the past decade made HDXMS an increasingly attractive tool for biochemists. In HDXMS, changes in the mass associated with the isotopic exchange between amide hydrogen atoms and surrounding deuterated solvent are measured. The

Chemical constituents of Chaenomeles sinensis twigs and their biological activity

• Joon Min Cha,
• Dong Hyun Kim,
• Lalita Subedi,
• Zahra Khan,
• Sang Un Choi,
• Sun Yeou Kim and
• Chung Sub Kim

Beilstein J. Org. Chem. 2020, 16, 3078–3085, doi:10.3762/bjoc.16.257

• flow rate of 2 mL/min. Low pressure liquid chromatography (LPLC) was performed with a LiChroprep Lobar-A Si 60 column (Merck, Darmstadt, Germany) and an FMI QSY-0 pump. Open columns packed with silica gel 60 (70–230 and 230–400 mesh; Merck), RP-18 silica gel (230–400 mesh; Merck, Darmstadt, Germany

Semiautomated glycoproteomics data analysis workflow for maximized glycopeptide identification and reliable quantification

• Steffen Lippold,
• Arnoud H. de Ru,
• Jan Nouta,
• Peter A. van Veelen,
• Magnus Palmblad,
• Manfred Wuhrer and
• Noortje de Haan

Beilstein J. Org. Chem. 2020, 16, 3038–3051, doi:10.3762/bjoc.16.253

• digest from affinity-purified immunoglobulins G and A was analyzed on a nano-reversed-phase liquid chromatography–tandem mass spectrometry platform with a high-resolution mass analyzer and higher-energy collisional dissociation fragmentation. Initial glycopeptide identification based on MS/MS data was

• -centered glycoproteomics aims at the characterization of macroheterogeneity and microheterogeneity of protein glycosylation [6]. Reversed-phase liquid chromatography coupled to high-resolution tandem mass spectrometry (RPLC–MS/MS) is a standard analytical method in the field of glycoproteomics [7]. The

A new method for the synthesis of diamantane by hydroisomerization of binor-S on treatment with sulfuric acid

• Rishat I. Aminov and
• Ravil I. Khusnutdinov

Beilstein J. Org. Chem. 2020, 16, 2534–2539, doi:10.3762/bjoc.16.205

• the reaction and the purity of the products were monitored by gas liquid chromatography on a Shimadzu GC-9A, GC-2014 instrument [2 m × 3 mm column, SE-30 silicone (5%) on Chromaton N-AW-HMDS as the stationary phase, temperature programming from 50 to 270 °С at 8 °C/min, helium as the carrier gas (47

Naphthalene diimide bis-guanidinio-carbonyl-pyrrole as a pH-switchable threading DNA intercalator

• Poulami Jana,
• Filip Šupljika,
• Carsten Schmuck and
• Ivo Piantanida

Beilstein J. Org. Chem. 2020, 16, 2201–2211, doi:10.3762/bjoc.16.185

• Alpha 1-4 2D plus freeze-drying apparatus from Christ. For analytical TLC SiO2-coated aluminum foils ALUGRAM SIL G/UV254 from MachereyNagel were used. Reversed-phase column chromatography was performed on an Armen Instrument Spot Flash Liquid Chromatography MPLC with RediSep C-18 Reversed-Phase columns

GlypNirO: An automated workflow for quantitative N- and O-linked glycoproteomic data analysis

• Toan K. Phung,
• Cassandra L. Pegg and
• Benjamin L. Schulz

Beilstein J. Org. Chem. 2020, 16, 2127–2135, doi:10.3762/bjoc.16.180

• diseased states [8]. The current state-of-the art technology for the characterisation, identification, and quantification of the glycome or glycoproteome is liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS) [9]. Popular and powerful glycoproteomic workflows typically involve standard

Accelerating fragment-based library generation by coupling high-performance photoreactors with benchtop analysis

• Quentin Lefebvre,
• Christophe Salomé and
• Thomas C. Fessard

Beilstein J. Org. Chem. 2020, 16, 982–988, doi:10.3762/bjoc.16.87

• photoreactors. Bottom, from left to right: photoreactor OFF, ON, and ON through protective yellow filter. TLC–MS equipment: analysis of 5 reactions in 5 minutes. Pre-QC validation by 60 MHz benchtop NMR. One-day workflow for fragment-based library generation. QC: Quality control. MPLC: Medium-pressure liquid

• chromatography. Scope of the fragment-based library generation: BCP-amines and azetidines. See Supporting Information File 1 for experimental details. Scope of the fragment-based library generation: pyrrolidines, piperidines and morpholines. See Supporting Information File 1 for experimental details. Supporting

Light-controllable dithienylethene-modified cyclic peptides: photoswitching the in vivo toxicity in zebrafish embryos

• Sergii Afonin,
• Oleg Babii,
• Aline Reuter,
• Volker Middel,
• Masanari Takamiya,
• Uwe Strähle,
• Igor V. Komarov and
• Anne S. Ulrich

Beilstein J. Org. Chem. 2020, 16, 39–49, doi:10.3762/bjoc.16.6

• prepared in >95% purity using preparative-scale high-performance liquid chromatography (HPLC). To establish the assay for screening the photoswitchable peptides, we first studied the toxicity of our prototype 2 by varying the assay conditions. The parent peptide GS 1 was used as a control. Although the

Synthesis and characterization of bis(4-amino-2-bromo-6-methoxy)azobenzene derivatives

• David Martínez-López,
• Amirhossein Babalhavaeji,
• Diego Sampedro and
• G. Andrew Woolley

Beilstein J. Org. Chem. 2019, 15, 3000–3008, doi:10.3762/bjoc.15.296

• thermal relaxation (τ1/2 ca. 10 min). Experimental General All commercial materials (solvents, reagents, and substrates) were used as received. SilicaFlash silica gel, P60, 40–63 µm particle size (SiliCycle) was used for column chromatography. High-performance liquid chromatography was performed on a

Bacterial terpene biosynthesis: challenges and opportunities for pathway engineering

• Eric J. N. Helfrich,
• Geng-Min Lin,
• Christopher A. Voigt and
• Jon Clardy

Beilstein J. Org. Chem. 2019, 15, 2889–2906, doi:10.3762/bjoc.15.283

• , remain to be explored [152]. One major bottleneck in these studies is the lack of high-throughput screening tools for terpenoid production and characterization. Most terpenoids do not have any chromogenic groups and their detection still relies on liquid chromatography–mass spectrometry setups, limiting

Safe and highly efficient adaptation of potentially explosive azide chemistry involved in the synthesis of Tamiflu using continuous-flow technology

• Cloudius R. Sagandira and
• Paul Watts

Beilstein J. Org. Chem. 2019, 15, 2577–2589, doi:10.3762/bjoc.15.251

• . Continuous-flow reactions were performed on a Labtrix® Start system and a Uniquis FlowSyn system. Reactions were monitored by Agilent 1200 high-performance liquid chromatography (HPLC) fitted with a UV–vis detector. HPLC analysis was performed on Agilent Zorbax C18-column (250 mm × 4.6 mm i.d, 5 µm) ambient

Excited state dynamics for visible-light sensitization of a photochromic benzil-subsituted phenoxyl-imidazolyl radical complex

• Yoichi Kobayashi,
• Yukie Mamiya,
• Katsuya Mutoh,
• Hikaru Sotome,
• Masafumi Koga,
• Hiroshi Miyasaka and
• Jiro Abe

Beilstein J. Org. Chem. 2019, 15, 2369–2379, doi:10.3762/bjoc.15.229

• time-resolved spectroscopies. Results and Discussion Steady-state absorption spectra The synthetic procedure of Benzil-PIC is described in the Experimental part. Benzil-PIC has two structural isomers (isomer A and isomer B) as shown in Scheme 1. These isomers were separated by high-performance liquid

• chromatography (HPLC), and each isomer was characterized by steady-state absorption spectra and time-dependent density functional theory (TDDFT) calculations as shown below. Figure 1 shows the steady-state absorption spectra of the two isomers of Benzil-PIC and PIC in benzene at 298 K. While the absorption of

Isolation of fungi using the diffusion chamber device FIND technology

• Benjamin Libor,
• Henrik Harms,
• Stefan Kehraus,
• Ekaterina Egereva,
• Max Crüsemann and
• Gabriele M. König

Beilstein J. Org. Chem. 2019, 15, 2191–2203, doi:10.3762/bjoc.15.216

• genus. From the solid, sea-salt containing cultures of H. cf. alpina the ethyl acetate soluble organic compounds were analysed. A first fractionation was achieved by vacuum liquid chromatography (VLC) on reversed-phase material yielding 4 fractions. 1H NMR analysis of these indicated the presence of

• by vacuum liquid chromatography (VLC) over Polygoprep 60-50 C18 stationary phase (Macherey-Nagel) using gradient elution from 0:100 (MeOH/H2O) to 100 % MeOH (25% steps) to yield 4 fractions. 100 mL of the mobile phase was used for each fraction. Fraction 3 was again fractionated by VLC under the

1,2,3,4-Tetrahydro-1,4,5,8-tetraazaanthracene revisited: properties and structural evidence of aromaticity loss

• Arnault Heynderickx,
• Sébastien Nénon,
• Olivier Siri,
• Vladimir Lokshin and
• Vladimir Khodorkovsky

Beilstein J. Org. Chem. 2019, 15, 2059–2068, doi:10.3762/bjoc.15.203

• Reagents and starting materials were used as received without further purification from Alfa Aesar and Aldrich. Analytical thin-layer chromatography (TLC) was done on Merck 60F254 silica gel plates from Macherey-Nagel. Detection of TLC components was accomplished using a 254/366 nm UV lamp. Column liquid

• chromatography was carried out on Merck silica gel 60 (70–230 mesh). Melting points were determined on a Büchi 510 apparatus in open glass capillaries and are uncorrected. The IR spectra were recorded with an Agilent 360FTIR instrument. The UV–vis absorption spectra were recorded with Ocean Optics USB 4000 and

Genome mining in Trichoderma viride J1-030: discovery and identification of novel sesquiterpene synthase and its products

• Xiang Sun,
• You-Sheng Cai,
• Yujie Yuan,
• Guangkai Bian,
• Ziling Ye,
• Zixin Deng and
• Tiangang Liu

Beilstein J. Org. Chem. 2019, 15, 2052–2058, doi:10.3762/bjoc.15.202

• efficiently enriched via an abundant FPP supply. Detection and characterisation of Tvi09626 products By semi-preparative high-performance liquid chromatography (HPLC), we purified compound 1 and compound 2 (23.1 mg and 13.2 mg, respectively). The structures of the two new compounds were characterised by 1D

Synthesis, enantioseparation and photophysical properties of planar-chiral pillar[5]arene derivatives bearing fluorophore fragments

• Guojuan Li,
• Chunying Fan,
• Guo Cheng,
• Wanhua Wu and
• Cheng Yang

Beilstein J. Org. Chem. 2019, 15, 1601–1611, doi:10.3762/bjoc.15.164

• derivatives. The racemic mixtures of P5A-DPA and P5A-Py were respectively separated by chiral high-performance liquid chromatography (HPLC). As shown in Figure 3a, injection of a P5A-DPA solution onto a DAICEL CHIRALPAK IA chiral HPLC column afforded two well-separated peaks of almost equal areas at 8.8 min

Synthesis and conformational preferences of short analogues of antifreeze glycopeptides (AFGP)

• Małgorzata Urbańczyk,
• Michał Jewgiński,
• Joanna Krzciuk-Gula,
• Jerzy Góra,
• Rafał Latajka and
• Norbert Sewald

Beilstein J. Org. Chem. 2019, 15, 1581–1591, doi:10.3762/bjoc.15.162

• otherwise. Analytical reversed-phase high-performance liquid chromatography (RP-HPLC) was carried out on a Thermo Separation Products system consisting of a UV 6000 diode array detector and a P 4000 pump equipped with a Phenomenex HPLC guard cartridge system (C12; 4 × 3.00 mm) and a Phenomenex Jupiter 4 µ

Efficient resolution of racemic crown-shaped cyclotriveratrylene derivatives and isolation and characterization of the intermediate saddle isomer

• Sven Götz,
• Andreas Schneider and
• Arne Lützen

Beilstein J. Org. Chem. 2019, 15, 1339–1346, doi:10.3762/bjoc.15.133

• achieved via high-performance liquid chromatography (HPLC) on a chiral stationary phase. This approach is a promising alternative to the previously reported resolution through formation of diastereomeric esters because it involves fewer synthetic steps and is less prone to thermal (re)racemization. During

• racemization. This is why Collet and co-workers also developed alternative methods for the chiral resolution of other CTVs and cryptophanes via high-performance liquid chromatography (HPLC) on a CHIRALPAK OT(+) column as stationary phase already in the 1980s [70]. Later on other chiral CTVs could also be

Easy, efficient and versatile one-pot synthesis of Janus-type-substituted fullerenols

• Marius Kunkel and
• Sebastian Polarz

Beilstein J. Org. Chem. 2019, 15, 901–905, doi:10.3762/bjoc.15.87

• and poured in methanol to precipitate the crude product. The obtained brown solid is washed with methanol to remove remaining TBAH and NaOH to obtain the sodium salt of the compound. The sodium salt compound can be ion exchanged (amberlite 120) prior to hydrophilic interaction liquid chromatography

Synthesis of acylglycerol derivatives by mechanochemistry

• Karen J. Ardila-Fierro,
• Andrij Pich,
• Marc Spehr,
• José G. Hernández and
• Carsten Bolm

Beilstein J. Org. Chem. 2019, 15, 811–817, doi:10.3762/bjoc.15.78

• liquid chromatography-chiral stationary phase (CSP-HPLC, for more details, see Supporting Information File 1). Access to enantiopure MAGs could be achieved under similar reaction conditions by starting from optically active commercially available silyl-protected glycidol derivatives [27][43]. Next, we

Efficient synthesis of 4-substituted-ortho-phthalaldehyde analogues: toward the emergence of new building blocks

• Clémence Moitessier,
• Ahmad Rifai,
• Pierre-Edouard Danjou,
• Isabelle Mallard and
• Francine Cazier-Dennin

Beilstein J. Org. Chem. 2019, 15, 721–726, doi:10.3762/bjoc.15.67

• -aminobutyric acid by high-performance liquid chromatography with molecular fluorescence detection [5]. In addition to the above manipulations, OPA and its derivatives are also valuable reagents [6] in organic chemistry, used to generate phthalimidine [7], imines [8], isoindole [9], 3-hydroxyindanone [10

New sesquiterpenoids from the South China Sea soft corals Clavularia viridis and Lemnalia flava

• Qihao Wu,
• Yuan Gao,
• Meng-Meng Zhang,
• Li Sheng,
• Jia Li,
• Xu-Wen Li,
• Hong Wang and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2019, 15, 695–702, doi:10.3762/bjoc.15.64

• . Reversed-phase (RP) HPLC purification was carried out on an Agilent 1260 series liquid chromatography system equipped with a DAD G1315D detector at 210 and 254 nm and with a semi-preparative ODS-HG-5 column [5 μm, 250 × 9.4 mm]. All solvents used for CC were of analytical grade, and solvents used for HPLC

Thermophilic phosphoribosyltransferases Thermus thermophilus HB27 in nucleotide synthesis

• Ilja V. Fateev,
• Ekaterina V. Sinitsina,
• Aiguzel U. Bikanasova,
• Maria A. Kostromina,
• Elena S. Tuzova,
• Larisa V. Esipova,
• Tatiana I. Muravyova,
• Alexei L. Kayushin,
• Irina D. Konstantinova and
• Roman S. Esipov

Beilstein J. Org. Chem. 2018, 14, 3098–3105, doi:10.3762/bjoc.14.289

• are displayed by double reciprocal plot (Figure 5). Determination of substrate specificity of TthHPRT was performed in comparative experiments with TthAPRT. The process of nucleotide synthesis was monitored by a liquid chromatography–mass spectrometry analysis of the reaction mixture. The data is

Novel solid-phase strategy for the synthesis of ligand-targeted fluorescent-labelled chelating peptide conjugates as a theranostic tool for cancer

• Sagnik Sengupta,
• Mena Asha Krishnan,
• Premansh Dudhe,
• Ramesh B. Reddy,
• Bishnubasu Giri,
• Sudeshna Chattopadhyay and
• Venkatesh Chelvam

Beilstein J. Org. Chem. 2018, 14, 2665–2679, doi:10.3762/bjoc.14.244

• analytical high-pressure liquid chromatography, (RP-HPLC) tR = 3.09 min. The molecular mass is determined by LCMS and HRMS (+ESI) calcd for [M − Cl]+ (C66H84N15O12S)+: 1310.6139; found, 1310.6352. Analytical HPLC method The purity of bioconjugates 13 and 17 were analyzed using a Dionex HPLC-Ultimate 3000

• chromatography method). Acetonitrile was removed under reduced pressure, and pure fractions were freeze-dried to yield DUPA rhodamine B conjugate 13 as red solid. The yield of 13 was 76% (41 mg) and the purity of the conjugate 13 is further confirmed by reverse phase analytical high-pressure liquid

• chromatography (RP-HPLC) tR = 9.8 min. The molecular mass is determined by LCMS. HRMS (+ESI) calcd for [M − Cl]+ (C89H121N14O21S)+: 1753.8546; found, 1753.8557. General procedure for solid-phase peptide synthesis of pteroate rhodamine B conjugate 17, pteroate-NH-(CH2)7CO-Lys(rhodamine B)-DAP-Asp-Cys: H-Cys(Trt