Recent advances in the application of isoindigo derivatives in materials chemistry

• Andrei V. Bogdanov and
• Vladimir F. Mironov

Beilstein J. Org. Chem. 2021, 17, 1533–1564, doi:10.3762/bjoc.17.111

• conditions, under laser irradiation, and the biocompatibility make it possible to conclude that the design of these compounds is promising for mass spectrometry, for catalysts for hydrogen production, and for photothermal cancer therapy. Representatives of isomeric bisoxindoles. Isoindigo-based OSCs with the

Chemical synthesis of C6-tetrazole ᴅ-mannose building blocks and access to a bioisostere of mannuronic acid 1-phosphate

• Eleni Dimitriou and
• Gavin J. Miller

Beilstein J. Org. Chem. 2021, 17, 1527–1532, doi:10.3762/bjoc.17.110

• % NaHCO3, EtOH, THF, rt, 24 h, 72%. Supporting Information Supporting Information File 218: Detailed experimental protocols and characterisation data; spectral NMR data (1H, 13C, 31P and HSQC NMR for compounds 2–5, 7–14, 16–18, 20 and 21). Acknowledgements We thank the EPSRC UK National Mass Spectrometry

Breaking paracyclophane: the unexpected formation of non-symmetric disubstituted nitro[2.2]metaparacyclophanes

• Suraj Patel,
• Tyson N. Dais,
• Paul G. Plieger and
• Gareth J. Rowlands

Beilstein J. Org. Chem. 2021, 17, 1518–1526, doi:10.3762/bjoc.17.109

• oxidation. Treatment with sulfuric acid returned unreacted starting material along with a trace of what is almost certainly, according to mass spectrometry, a bis(sulfonic acid), although with the quantities isolated, we were unable to determine which isomer. Reaction with triflic acid or perchloric acid

• . ESIMS was recorded on a Dionex UltiMate 3000. High-resolution mass spectrometry was performed using a ThermoScientific Q Exactive Focus Hybrid Quadrupole-Orbitrap mass spectrometer or a Bruker Daltonics MicrOTOF spectrometer. Infrared spectroscopy of compounds was completed on a ThermoFisher Nicolet iS5

Cascade intramolecular Prins/Friedel–Crafts cyclization for the synthesis of 4-aryltetralin-2-ols and 5-aryltetrahydro-5H-benzo[7]annulen-7-ols

• Jie Zheng,
• Shuyu Meng and
• Quanrui Wang

Beilstein J. Org. Chem. 2021, 17, 1481–1489, doi:10.3762/bjoc.17.104

• isolated products as well as copies of NMR spectra and XRPD data for compound 21. Supporting Information File 182: Experimental section. Acknowledgements We thank Mr. G. Tang for acquiring high-resolution mass spectrometry data. Funding The authors acknowledge the financial support from the National

Design, synthesis and photophysical properties of novel star-shaped truxene-based heterocycles utilizing ring-closing metathesis, Clauson–Kaas, Van Leusen and Ullmann-type reactions as key tools

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2021, 17, 1374–1384, doi:10.3762/bjoc.17.96

• mixture of EtOAc and petroleum ether. Characterization of the intermediates and final compounds were performed using 1H and 13C NMR, mass spectrometry and IR spectroscopy. FTIR spectra of the compounds were recorded on an Aligent FTIR spectrometer (ATR module of Cary 630 FTIR, Agilent Technologies) from

Fritsch–Buttenberg–Wiechell rearrangement of magnesium alkylidene carbenoids leading to the formation of alkynes

• Tsutomu Kimura,
• Koto Sekiguchi,
• Akane Ando and
• Aki Imafuji

Beilstein J. Org. Chem. 2021, 17, 1352–1359, doi:10.3762/bjoc.17.94

• JNM-LA 500, Bruker AVANCE DPX 300, and Bruker AVANCE DPX 400 spectrometers. Mass spectrometry (MS) experiments were conducted at 70 eV by direct injection with a HITACHI M-80B mass spectrometer. Fast atom bombardment (FAB) mass spectra were obtained with a mixture of m-nitrobenzyl alcohol and glycerol

A new glance at the chemosphere of macroalgal–bacterial interactions: In situ profiling of metabolites in symbiosis by mass spectrometry

• Marine Vallet,
• Filip Kaftan,
• Veit Grabe,
• Fatemeh Ghaderiardakani,
• Simona Fenizia,
• Aleš Svatoš,
• Georg Pohnert and
• Thomas Wichard

Beilstein J. Org. Chem. 2021, 17, 1313–1322, doi:10.3762/bjoc.17.91

• Marine Vallet Filip Kaftan Veit Grabe Fatemeh Ghaderiardakani Simona Fenizia Ales Svatos Georg Pohnert Thomas Wichard Research Group Phytoplankton Community Interactions, Max Planck Institute for Chemical Ecology, Jena, Germany Research Group Mass Spectrometry/Proteomics, Max Planck Institute for

• used mass spectrometry profiling and imaging techniques with high spatial resolution and sensitivity to gain a new perspective on the mutualistic interactions between bacteria and macroalgae. Using atmospheric pressure scanning microprobe matrix-assisted laser desorption/ionisation high-resolution mass

• distributions of metabolites and identifying specific symbiotic bacteria. Keywords: algae; AP-SMALDI; ectoine; holobiont; high-resolution mass spectrometry; mass spectrometry imaging; marine bacteria; Ulva; Introduction In intertidal zones with high temporal and spatial ecosystem variations, bacteria and

Structural effects of meso-halogenation on porphyrins

• Keith J. Flanagan,
• Maximilian Paradiz Dominguez,
• Zoi Melissari,
• Hans-Georg Eckhardt,
• René M. Williams,
• Dáire Gibbons,
• Caroline Prior,
• Gemma M. Locke,
• Alina Meindl,
• Aoife A. Ryan and
• Mathias O. Senge

Beilstein J. Org. Chem. 2021, 17, 1149–1170, doi:10.3762/bjoc.17.88

• were measured with a Stuart SP-10 melting point apparatus. A Bruker Advance III 400 MHz spectrometer was employed for 1H (400.13 MHz), and 13C (100.61 MHz) NMR spectra. All NMR experiments were performed at room temperature. Mass spectrometry analysis was performed with a Q-Tof Premier Waters MALDI

Application of the Meerwein reaction of 1,4-benzoquinone to a metal-free synthesis of benzofuropyridine analogues

• Rashmi Singh,
• Tomas Horsten,
• Rashmi Prakash,
• Swapan Dey and
• Wim Dehaen

Beilstein J. Org. Chem. 2021, 17, 977–982, doi:10.3762/bjoc.17.79

• support. KU Leuven (Project C14/19/78). R. S. thanks IIT (ISM) Dhanbad for a graduate fellowship. Mass spectrometry was made possible by the support of the Hercules Foundation of the Flemish Government (grant 20100225-7).

DNA with zwitterionic and negatively charged phosphate modifications: Formation of DNA triplexes, duplexes and cell uptake studies

• Yongdong Su,
• Maitsetseg Bayarjargal,
• Tracy K. Hale and
• Vyacheslav V. Filichev

Beilstein J. Org. Chem. 2021, 17, 749–761, doi:10.3762/bjoc.17.65

• was confirmed by electrospray ionization mass spectrometry (ESIMS) in the negative mode (Table 1). For clarity, we introduced the following nomenclature of the ONs synthesised. The prefix 5ʼ- or 3ʼ- with either N+ or Ts- means that the first phosphate at the 5ʼ- or 3ʼ-end was modified; m-N+ or m-Ts

• Information Supporting Information File 62: Experimental part. Acknowledgements Manawatu Microscopy and Imaging Centre, NMR and mass spectrometry facilities at Massey University, and the assistance of Mr. Raoul Solomon, Dr. Patrick J. B. Edwards, and Mr. David Lun are gratefully acknowledged. We thank Dr

Effective microwave-assisted approach to 1,2,3-triazolobenzodiazepinones via tandem Ugi reaction/catalyst-free intramolecular azide–alkyne cycloaddition

• Maryna O. Mazur,
• Oleksii S. Zhelavskyi,
• Eugene M. Zviagin,
• Svitlana V. Shishkina,
• Vladimir I. Musatov,
• Maksim A. Kolosov,
• Elena H. Shvets,
• Anna Yu. Andryushchenko and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2021, 17, 678–687, doi:10.3762/bjoc.17.57

• ). Ugi product 6aaa (first letter – isocyanide code, second letter – amine code, third – carboxylic acid code) was the first to isolate in our trials and its structure was confirmed by X-ray analysis (Figure 3) in addition to mass spectrometry, elemental analysis, 1H and 13C NMR data. Compound 6

[2 + 1] Cycloaddition reactions of fullerene C₆₀ based on diazo compounds

• Yuliya N. Biglova

Beilstein J. Org. Chem. 2021, 17, 630–670, doi:10.3762/bjoc.17.55

• 35 [92] and 36–38 (Figure 4) [93]. A synthesis based on benzo-18-crown-6 to give 39 showed that attachment of the crown ether to the surfaces of fullerene molecules makes it easier to detect them by mass spectrometry [94]. This method was used to incorporate benzocrown ether residues in order to

Synthesis and properties of oligonucleotides modified with an N-methylguanidine-bridged nucleic acid (GuNA[Me]) bearing adenine, guanine, or 5-methylcytosine nucleobases

• Naohiro Horie,
• Takao Yamaguchi,
• Shinji Kumagai and
• Satoshi Obika

Beilstein J. Org. Chem. 2021, 17, 622–629, doi:10.3762/bjoc.17.54

• acetate buffer (pH 7.0). The purity and structure of the oligonucleotides were confirmed by HPLC and MALDI–TOF mass spectrometry, respectively. UV melting experiments and melting profiles The UV melting experiments were carried out using SHIMADZU UV-1650PC and SHIMADZU UV-1800 spectrometers equipped with

Breakdown of 3-(allylsulfonio)propanoates in bacteria from the Roseobacter group yields garlic oil constituents

• Anuj Kumar Chhalodia and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2021, 17, 569–580, doi:10.3762/bjoc.17.51

• stripping apparatus (CLSA) [33], followed by the extraction of the filters with CH2Cl2 and analysis by gas chromatography–mass spectrometry (GC–MS) of the resulting extracts. Most of the compounds were readily identified by the comparison of their mass spectra and retention indices to published data. Every

Amino- and polyaminophthalazin-1(2H)-ones: synthesis, coordination properties, and biological activity

• Zbigniew Malinowski,
• Emilia Fornal,
• Agata Sumara,
• Renata Kontek,
• Karol Bukowski,
• Beata Pasternak,
• Dariusz Sroczyński,
• Joachim Kusz,
• Magdalena Małecka and
• Monika Nowak

Beilstein J. Org. Chem. 2021, 17, 558–568, doi:10.3762/bjoc.17.50

• with a donor nitrogen atom could result in the formation of complexes following a different way of coordination with the metal ion than described in the literature [41]. The complexing properties of compounds 5i, 6d, and 7 were investigated by mass spectrometry (ESIMS). The spectra were recorded after

Synthesis and physicochemical evaluation of fluorinated lipopeptide precursors of ligands for microbubble targeting

• Masayori Hagimori,
• Estefanía E. Mendoza-Ortega and
• Marie Pierre Krafft

Beilstein J. Org. Chem. 2021, 17, 511–518, doi:10.3762/bjoc.17.45

• was stepwisely elongated, and eventually conjugated with the (perfluoroalkyl)ethyl acids (Scheme 2). After the cleavage from the resin, the Fmoc groups of the amino acids were removed, and the F-lipopeptides were purified using a dialysis membrane. According to mass spectrometry, FTIR, and HPLC

• Information Supporting Information File 46: Mass spectrometry and FTIR data as well as RP-HPLC chromatograms of lipopeptides 1–4. Funding The work was supported by JSPS KAKENHI Grant Number JP18KK0439 and JP20K08139. We also acknowledge CONACYT (Mexico) for a Ph.D. fellowship (E.E.M.O., grant #459199).

Unexpected rearrangements and a novel synthesis of 1,1-dichloro-1-alkenones from 1,1,1-trifluoroalkanones with aluminium trichloride

• Beatrice Lansbergen,
• Catherine S. Meister and
• Michael C. McLeod

Beilstein J. Org. Chem. 2021, 17, 404–409, doi:10.3762/bjoc.17.36

• mass spectrometry and so it was converted to carboxylic acids 14 and 15 by the treatment with silica gel and NaOH, respectively, in order to confirm its identity. A possible mechanism for the formation of 13 from 5n could involve the formation of a terminal carbocation from trichloroalkanone 8n

• Supporting Information File 58: Detailed experimental procedures and NMR spectra for all compounds referenced. Acknowledgements We thank Mr Martin Annau for his valuable assistance in NMR interpretation and structure elucidation, Mrs Susanne Ries for performing the mass spectrometry measurements and Dr

Synthesis of legonmycins A and B, C(7a)-hydroxylated bacterial pyrrolizidines

• Wilfred J. M. Lewis,
• David M. Shaw and
• Jeremy Robertson

Beilstein J. Org. Chem. 2021, 17, 334–342, doi:10.3762/bjoc.17.31

• diamond ATR module, and νmax values are expressed in cm−1. HRMS measurements were performed by the Mass Spectrometry Service at the Chemistry Research Laboratory, University of Oxford, using a Bruker microTOF spectrometer. Values of m/z are calculated to 0.0001 Daltons from the chemical formula, and all

Regioselective chemoenzymatic syntheses of ferulate conjugates as chromogenic substrates for feruloyl esterases

• Olga Gherbovet,
• Fernando Ferreira,
• Apolline Clément,
• Mélanie Ragon,
• Julien Durand,
• Sophie Bozonnet,
• Michael J. O'Donohue and
• Régis Fauré

Beilstein J. Org. Chem. 2021, 17, 325–333, doi:10.3762/bjoc.17.30

• (t), doublet of doublets (dd), doublet of doublets of doublets (ddd), broad (br), and quadruplet of triplets (qt) as abbreviations. Analyses and assignments were made using 1D (1H, 13C, and J-modulated spin–echo (Jmod)) and 2D NMR experiments (COSY and HSQC). High-resolution mass spectrometry (HRMS

¹⁹F NMR as a tool in chemical biology

• Diana Gimenez,
• Aoife Phelan,
• Cormac D. Murphy and
• Steven L. Cobb

Beilstein J. Org. Chem. 2021, 17, 293–318, doi:10.3762/bjoc.17.28

• ). Each independent intermediate was characterized on the basis of its 19F NMR chemical shift and the kinetics by which each species formed or decayed were evaluated in real-time. By combining the 19F NMR data with that provided by complementary analytical techniques, mass spectrometry (electrospray

• widely used by those investigating the biodegradation of fluorinated xenobiotics, with researchers more commonly relying on liquid or gas chromatography–mass spectrometry methods. Objectively, these techniques are much more sensitive than 19F NMR, provide more structural information and are probably more

Direct synthesis of anomeric tetrazolyl iminosugars from sugar-derived lactams

• Michał M. Więcław and
• Bartłomiej Furman

Beilstein J. Org. Chem. 2021, 17, 115–123, doi:10.3762/bjoc.17.12

• -5-yl)-iminosugars, using 2,3,5-tri-O-benzyl-ᴅ-ribofuranose- and -arabinofuranose-derived lactams as substrates were made. Very unexpectedly, we failed to isolate such products although we did observe their formation via mass spectrometry of the reaction mixtures. Employing alternative procedures did

Control over size, shape, and photonics of self-assembled organic nanocrystals

• Chen Shahar,
• Yaron Tidhar,
• Yunmin Jung,
• Haim Weissman,
• Sidney R. Cohen,
• Ronit Bitton,
• Iddo Pinkas,
• Gilad Haran and
• Boris Rybtchinski

Beilstein J. Org. Chem. 2021, 17, 42–51, doi:10.3762/bjoc.17.5

• applicability of organic nanocrystals. Experimental General information The 1H and 13C NMR spectra were recorded at 20 °C on a 300 MHz NMR spectrometer (Bruker). Electrospray ionization (ESI) mass spectrometry was performed using a Micromass Platform instrument. UV–vis absorption and fluorescence measurements

The fluorescence of a mercury probe based on osthol

• Guangyan Luo,
• Zhishu Zeng,
• Lin Zhang,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2021, 17, 22–27, doi:10.3762/bjoc.17.3

• fluorescence, UV–vis spectrophotometry, mass spectrometry, and 1H NMR spectroscopy, and the recognition mechanism is discussed. The results showed that OST and Hg2+ can form a complex with a stoichiometric ratio of 1:1. The binding constant was 1.552 × 105 L∙mol−1, having a highly efficient and specific

• irreversible nerve damage. Therefore, it is very important to develop a highly sensitive and selective method for mercury detection. At present, the detection of mercury mainly includes atomic absorption and atomic emission spectrometry [4], inductively coupled plasma mass spectrometry [5][6], and capillary

• UV absorption intensity was achieved at n(Hg2+)/n((OST) + (Hg2+)) = 0.5 at 325 nm, indicating that the binding ratio of the OST probe to Hg2+ was 1:1. Combined with mass spectrometry data (Figure 5), the fragment peak of ESIMS at m/z 892.5422 corresponded to [OST2–Hg2]+ (calculated as 892.5429

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

• proteins and other biological molecules, all of which have their own biological role and chemical interactions. Characterisation methods that can be employed to study PPIs can be divided into four categories: atomic resolution methods, mass spectrometry methods, biophysical methods, and computational

• (or any other organic molecule [19]) structure. A resolution of up to 0.6 Å (RNA-binding protein FUS, residues 37–42, EMD-0699, PDB: 6KJ4 [20]) were obtained when using this method. Nannenga and Gonen gave a detailed account on MicroED [21]. As another category, mass spectrometry methods are used to

• determine the amino acid sequences at the PPIs site. Examples include protein painting [22] and chemical cross-linking [23], hydrogen–deuterium exchange mass spectrometry (HDXMS) [24], and fast photochemical oxidation of proteins [25]. In protein painting, small-molecular dyes are introduced to protein

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

• complex, reflecting the high structural diversity of peptide and glycan portions. The use of glycopeptide-centered glycoproteomics by mass spectrometry is rapidly evolving in many research areas, leading to a demand in reliable data analysis tools. In recent years, several bioinformatic tools were

• 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

• quantification. Keywords: bioinformatics; cysteine oxidation; glycoproteomics; immunoglobulins; mass spectrometry; Introduction Protein glycosylation mainly occurs in the form of N- and O-glycosylation. N-Glycans are attached to Asn within an amino acid consensus sequence (Asn-Xxx-Ser/Thr, Xxx ≠ Pro) and O