Preparation of anthracene-based tetraperimidine hexafluorophosphate and selective recognition of chromium(III) ions

• Qing-Xiang Liu,
• Feng Yang,
• Zhi-Xiang Zhao,
• Shao-Cong Yu and
• Yue Ding

Beilstein J. Org. Chem. 2019, 15, 2847–2855, doi:10.3762/bjoc.15.278

• of Cr3+ ions occupies an important position. Chromium(III) is an essential microelement for humans and animals, and it plays an important role in glucose and lipid metabolism in the body [9][10]. The deficiency of chromium(III) in the human body leads to various diseases, such as diabetes as well as

Chemical tuning of photoswitchable azobenzenes: a photopharmacological case study using nicotinic transmission

• Lorenzo Sansalone,
• Jun Zhao,
• Matthew T. Richers and
• Graham C. R. Ellis-Davies

Beilstein J. Org. Chem. 2019, 15, 2812–2821, doi:10.3762/bjoc.15.274

• labeling, labeling solutions were checked by UPLC. The external solution was (in mM): 140 NaCl, 2.8 KCl, 2 CaCl2, 2 MgCl2, 10 HEPES, 12 glucose (pH 7.3 with NaOH). Compound 1 (0.05 mM) was dissolved in external solution and sonicated for 5 min. HEK293 cells with green fluorescence were chosen for recording

• KCl, 1.25 NaH2PO4, 7 MgCl2, 0.5 CaCl2, 26 NaHCO3, 10 glucose, 100 sucrose, 3 sodium pyruvate, 1.3 sodium ascorbate equilibrated with 95% O2/5% CO2 (pH 7.3–7.4). The brain slices were then incubated for 15 min at 33 °C in artificial cerebrospinal fluid (ACSF, mM: 125 NaCl, 2.5 KCl, 1.25 NaH2PO4, 1

• MgCl2, 2 CaCl2, 26 NaHCO3, 10 glucose, 3 sodium pyruvate, 1.3 sodium ascorbate; 95% O2/5% CO2, pH 7.3–7.4) and held at room temperature. Brain slices were then transferred to the recording chamber of a BX-61 microscope (Olympus, PennValley, PA, USA) and superfused with ACSF at room temperature. Medial

Skeletocutins M–Q: biologically active compounds from the fruiting bodies of the basidiomycete Skeletocutis sp. collected in Africa

• Tian Cheng,
• Clara Chepkirui,
• Cony Decock,
• Josphat C. Matasyoh and
• Marc Stadler

Beilstein J. Org. Chem. 2019, 15, 2782–2789, doi:10.3762/bjoc.15.270

• standard turbidity in casein-peptone soymeal-peptone (CASO) medium containing 4% glucose at pH 7.0 for biofilm formation. Methanol was used as negative control, while tetracycline was used as positive control. All experiments were made in triplicates. Nematicidal activity assay The nematicidal activity of

Chemical synthesis of the pentasaccharide repeating unit of the O-specific polysaccharide from Escherichia coli O132 in the form of its 2-aminoethyl glycoside

• Debasish Pal and
• Balaram Mukhopadhyay

Beilstein J. Org. Chem. 2019, 15, 2563–2568, doi:10.3762/bjoc.15.249

• , the disaccharide donor 16 may be prepared from monosaccharide acceptor 15 and donor 14. The monosaccharide building blocks can be prepared from commercially available ᴅ-glucose, ᴅ-galactose, ᴅ-glucosamine hydrochloride and ʟ-rhamnose through rational protecting group manipulations (Figure 2

Indium-mediated C-allylation of melibiose

• Christian Denner,
• Manuel Gintner,
• Hanspeter Kählig and
• Walther Schmid

Beilstein J. Org. Chem. 2019, 15, 2458–2464, doi:10.3762/bjoc.15.238

• glucose moiety allowing most spatial freedom for the elongation reaction at the anomeric position of the reducing end of the disaccharide (Scheme 1). First, we investigated different reaction parameters such as the metal species, the solvent system, the activation by sonication as well as the temperature

Sugar-derived oxazolone pseudotetrapeptide as γ-turn inducer and anion-selective transporter

• Sachin S. Burade,
• Sushil V. Pawar,
• Tanmoy Saha,
• Navanath Kumbhar,
• Amol S. Kotmale,
• Manzoor Ahmad,
• Pinaki Talukdar and
• Dilip D. Dhavale

Beilstein J. Org. Chem. 2019, 15, 2419–2427, doi:10.3762/bjoc.15.234

• demonstrated better selective Cl− ion transport activity as compared to the pseudodipeptide 1. To the best of our knowledge, this is the first report on the formation of oxazolone peptides from TSFAA that induces a γ-turn and demonstrate ion transport activity. Results and Discussion At first, ᴅ-glucose was

Isolation and biosynthesis of an unsaturated fatty acid with unusual methylation pattern from a coral-associated bacterium Microbulbifer sp.

• Amit Raj Sharma,
• Enjuro Harunari,
• Tao Zhou,
• Agus Trianto and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2019, 15, 2327–2332, doi:10.3762/bjoc.15.225

• mL of marine broth 2216 (Difco) as a seed culture. The seed culture was incubated at 30 °C on a rotary shaker at 200 rpm for 2 days. Three mL of seed culture was inoculated into twenty-five 500 mL K-1 flasks each containing 100 mL of A11M production medium, which consists of glucose 0.2%, soluble

Archangelolide: A sesquiterpene lactone with immunobiological potential from Laserpitium archangelica

• Silvie Rimpelová,
• Michal Jurášek,
• Lucie Peterková,
• Jiří Bejček,
• Vojtěch Spiwok,
• Miloš Majdl,
• Michal Jirásko,
• Miloš Buděšínský,
• Juraj Harmatha,
• Eva Kmoníčková,
• Pavel Drašar and
• Tomáš Ruml

Beilstein J. Org. Chem. 2019, 15, 1933–1944, doi:10.3762/bjoc.15.189

• ) and, the cells were incubated for another 24, 48 and 72 h. Next, the medium was removed and the cells were incubated with 5 µL of WST-1 dissolved in 100 µL of high glucose DMEM without phenol red with 10% FBS for 2 h. Then, the absorbance was measured. Cells incubated with a vehicle (DMSO) in medium

Synthesis of a [6]rotaxane with singly threaded γ-cyclodextrins as a single stereoisomer

• Jason Yin Hei Man and
• Ho Yu Au-Yeung

Beilstein J. Org. Chem. 2019, 15, 1829–1837, doi:10.3762/bjoc.15.177

• -CD), seven (β-CD) and eight (γ-CD) glucose units are important molecular hosts that show binding to a wide range of compounds and find applications in different fields including food and pharmaceutical industries [1][2][3][4][5]. CDs are of cone shape with two different openings: a narrower primary

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

• protocol also provided a concise route for the synthesis of the antiulcer drug zolimidine in 95% yield. A three-component coupling reaction (3-CCR) for the synthesis of N-fused pyridines was reported by Balijapalli and Iyer [40]. The reaction was catalyzed by CuO/CuAl2O4 and ᴅ-glucose. The reaction had

• been tried with various Cu(I)- and Cu(II)-based catalysts but the use of a mixed nano-CuO/CuAl2O4 and ᴅ-glucose system has resulted in appreciable yields. This three-component one-pot reaction involved 2-AP, phenylacetylene and substituted benzaldehydes as the starting substrates (Scheme 34). The

Synthesis of 9-O-arylated berberines via copper-catalyzed C_Ar–O coupling reactions

• Qiaoqiao Teng,
• Xinhui Zhu,
• Qianqian Guo,
• Weihua Jiang,
• Jiang Liu and
• Qi Meng

Beilstein J. Org. Chem. 2019, 15, 1575–1580, doi:10.3762/bjoc.15.161

• elaborate motifs such as heterocycles [10][11][12], glucose [13], nitric oxide [14], and the multidrug-resistance pump inhibitor 5-nitro-2-phenylindole (INF55) [15] have been covalently attached to BBR, further widening its pharmacological spectrum. Aromatic rings are another family of substituents having

2,3-Dibutoxynaphthalene-based tetralactam macrocycles for recognizing precious metal chloride complexes

• Li-Li Wang,
• Yi-Kuan Tu,
• Huan Yao and
• Wei Jiang

Beilstein J. Org. Chem. 2019, 15, 1460–1467, doi:10.3762/bjoc.15.146

• recognition of glucose in water [21][22][23]. However, the aromatic sidewalls of these tetralactams are currently limited to benzene, anthracene and their derivatives (Scheme 1). The extension of the sidewalls to naphthalenes should be an important supplement to the previous works, and may even lead to

Anomeric sugar boronic acid analogues as potential agents for boron neutron capture therapy

• Daniela Imperio,
• Erika Del Grosso,
• Silvia Fallarini,
• Grazia Lombardi and
• Luigi Panza

Beilstein J. Org. Chem. 2019, 15, 1355–1359, doi:10.3762/bjoc.15.135

• boron-containing carbohydrate derivatives for BNCT has received special attention because of the sugar-preferential uptake by tumor cells [3]. Tumor cells perform glycolysis at a faster rate than their noncancerous tissue counterparts, so increasing the glucose consumption with respect to healthy cells

• . Galactose and fructose also allow tumor growth in the absence of glucose. Boronic acid derivatives have gained interest in the last years in different fields such as the development of enzyme inhibitors, drug delivery polymers, saccharide sensors and as boron carriers for BNCT, e.g., amino acid derivatives

Genomics-inspired discovery of massiliachelin, an agrochelin epimer from Massilia sp. NR 4-1

• Jan Diettrich,
• Hirokazu Kage and
• Markus Nett

Beilstein J. Org. Chem. 2019, 15, 1298–1303, doi:10.3762/bjoc.15.128

• (0.5 g/L yeast extract, 0.5 g/L proteose peptone, 0.5 g/L casamino acids, 0.5 g/L glucose, 0.5 g/L soluble starch, 0.3 g/L sodium pyruvate, 0.3 g/L K2HPO4 and 0.05 g/L MgSO4·7H2O, pH 7.2). The cultures were shaken at 160 rpm and 30 °C. After seven days of cultivation the fermentation broth was

Steroid diversification by multicomponent reactions

• Leslie Reguera,
• Cecilia I. Attorresi,
• Javier A. Ramírez and
• Daniel G. Rivera

Beilstein J. Org. Chem. 2019, 15, 1236–1256, doi:10.3762/bjoc.15.121

• conjugation [62][63]. Cytotoxic spirostan saponins were chosen as model compounds for the preparation of Ugi-derived analogues, such as 55 and 56 suitable for biological evaluation [62]. Besides the glucose unit, other trisaccharidic moieties (e.g., β-chacotrioside) could also be conjugated to functionalized

Molecular recognition using tetralactam macrocycles with parallel aromatic sidewalls

• Dong-Hao Li and
• Bradley D. Smith

Beilstein J. Org. Chem. 2019, 15, 1086–1095, doi:10.3762/bjoc.15.105

• -Bu). a) Chemical structure of β-D-glucopyranose and the solid-state structure of its complexes with macrocycle B (X = CH). b) Schematic view of tetralactam B encapsulating glucose (R = O) or glucosammonium (R = NH2+) with stabilizing secondary interactions provided by back-folding of a peripherally

Stereo- and regioselective hydroboration of 1-exo-methylene pyranoses: discovery of aryltriazolylmethyl C-galactopyranosides as selective galectin-1 inhibitors

• Alexander Dahlqvist,
• Axel Furevi,
• Niklas Warlin,
• Hakon Leffler and
• Ulf J. Nilsson

Beilstein J. Org. Chem. 2019, 15, 1046–1060, doi:10.3762/bjoc.15.102

• excellent diastereoselectivities (1:19 and 1:99 α:β ratio, respectively). Hydroboration of the glucose enol ether 6 afforded a mixture of both diastereomers (1:2.3 α:β ratio) in good yield (43% β and 18% α isolated yields, respectively). Identification of the diastereomers was accomplished by NOESY

• -interacting glucose unit in methyl β-lactoside (12) and at the same time induces a significantly better selectivity than that of methyl β-lactoside (12). Taken together, the 4-fluorophenyltriazole 1b represents the most potent mono-galactoside-derived galectin-1 inhibitor, albeit with an apparently lower

• ]. Hence, one monosaccharide moiety, glucose/N-acetylglucosamine of the common disaccharide ligands lactose/N-acetyllactosamine has effectively been replaced with an aryltriazole motif, which is chemically wholly dissimilar and more selective. This opens a route towards galectin inhibitors with improved

New terpenoids from the fermentation broth of the edible mushroom Cyclocybe aegerita

• Frank Surup,
• Florian Hennicke,
• Nadine Sella,
• Maria Stroot,
• Steffen Bernecker,
• Sebastian Pfütze,
• Marc Stadler and
• Martin Rühl

Beilstein J. Org. Chem. 2019, 15, 1000–1007, doi:10.3762/bjoc.15.98

• ) 5.00 g/L, D(+)-sucrose (Carl Roth GmbH & Co, Karlsruhe, Germany) 4.00 g/L, D-mannitol (AppliChem GmbH, ITW Company, Darmstadt, Germany) 4.00 g/L, D-glucose monohydrate (Cargill Holding Germany GmbH, Krefeld, Germany) 1.50 g/L, CaCO3 (Carl Roth GmbH & Co KG, Karlsruhe, Germany) 1.50 g/L, lactalbumin

• Drive Systems) at 23 °C. After one week of incubation the glucose concentration in the medium was tested daily. If no more free glucose could be found in the medium, the cultivation was extracted. Extraction The mycelium was separated from the fermentation broth with the help of a fluted filter. The

Towards the preparation of synthetic outer membrane vesicle models with micromolar affinity to wheat germ agglutinin using a dialkyl thioglycoside

• Dimitri Fayolle,
• Nathalie Berthet,
• Bastien Doumeche,
• Olivier Renaudet,
• Peter Strazewski and
• Michele Fiore

Beilstein J. Org. Chem. 2019, 15, 937–946, doi:10.3762/bjoc.15.90

• , DCM UMR 5250, F-38000 Grenoble, France 10.3762/bjoc.15.90 Abstract A series of alkyl thioglycosides and alkyl thiodiglycosides bearing glucose and N-acetylglucosamine residues were prepared by thiol–ene coupling in moderate to good yields (40–85%). Their binding ability towards wheat germ agglutinin

• GlcNAc monomer displays only 35 mM (Table 1). Compounds 4 and 7 bearing one and two glucose residues served as negative controls as WGA has no affinity towards glucose. This result clearly shows the high potential of the lipophilic n-alkyl thioglycoconjugates for lectine binding. In particular, compound

• to prevent the binding to primary sites. Conclusion A series of glucose and N-acetyl glucosamine-based thioglycolipids were synthesized for the first time by using thiol–ene coupling in the absence of protecting groups and in good yields. Monosaccharides where selected on the basis of similar

New α- and β-cyclodextrin derivatives with cinchona alkaloids used in asymmetric organocatalytic reactions

• Iveta Chena Tichá,
• Simona Hybelbauerová and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2019, 15, 830–839, doi:10.3762/bjoc.15.80

• part of the spectrum consists of the CD region (5.50–3.20 ppm) with H-1 atoms of unsubstituted glucose units (4.80 ppm) and H-1I (5.03 ppm) for the substituted glucose. The signals of the H-2, H-3, H-4 and H-6 atoms of unsubstituted units are observed at around 4.00–3.00 ppm; on the other hand, the

• identified in the region around 2.00–1.20 ppm. Subsequently, 13C NMR, DEPT-edited HSQC and HMBC spectra also confirmed the substitution on the primary rim of the CD skeleton (Figure 4). The C-6 atom of the substituted glucose unit is correlated with the hydrogen signal of the triazole ring (50.41 ppm of C-6I

• alkaloid attachment to the CD skeleton through the triazole by 2D NMR measurements. This thorough investigation revealed no triple bond and a new triazole hydrogen signal while correlating carbon C6 of the substituted glucose unit with the triazole. Therefore, the prepared CD derivatives are substituted on

Synthesis of functionalized diazocines for application as building blocks in photo- and mechanoresponsive materials

• Widukind Moormann,
• Daniel Langbehn and
• Rainer Herges

Beilstein J. Org. Chem. 2019, 15, 727–732, doi:10.3762/bjoc.15.68

• hydrazine is quite stable towards reduction to the diamine, and can easily be reoxidized to the azo compound using CuCl2/O2. The yields are higher and more reproducible using the above reduction/reoxidation scheme. Previously applied reducing agents include Ba(OH)2/Zn [27], glucose/NaOH [20], Pb/NEt3/HCOOH

Homo- and hetero-difunctionalized β-cyclodextrins: Short direct synthesis in gram scale and analysis of regiochemistry

• Gábor Benkovics,
• Mihály Bálint,
• Éva Fenyvesi,
• Erzsébet Varga,
• Szabolcs Béni,
• Konstantina Yannakopoulou and
• Milo Malanga

Beilstein J. Org. Chem. 2019, 15, 710–720, doi:10.3762/bjoc.15.66

• react only with the more distant glucose units, therefore only AC and AD disubstitution takes place. The detailed study of the reaction mechanisms is out of the scope of this paper, however, the different mechanisms and reaction intermediates are likely responsible for the distinct outcome of the two

• on adjacent glucose units is not favored. The inspection of the reversed-phase HPLC chromatograms of reactions 1–3 (Figure 2) reveals that the individual diazido-β-CD regioisomers have significant retention time differences if water/acetonitrile gradient elution is applied. These differences can be

Influence of per-O-sulfation upon the conformational behaviour of common furanosides

• Alexey G. Gerbst,
• Vadim B. Krylov,
• Dmitry A. Argunov,
• Maksim I. Petruk,
• Arsenii S. Solovev,
• Andrey S. Dmitrenok and
• Nikolay E. Nifantiev

Beilstein J. Org. Chem. 2019, 15, 685–694, doi:10.3762/bjoc.15.63

• drastic changes of the ring conformation occurred while sometimes only the conformation of the exocyclic C4–C5 linkage changed. Herein we describe a combined quantum chemical and NMR conformational investigation of three common monosaccharide furanosides as their propyl glycosides: α-mannose, β-glucose

Synthesis of the aglycon of scorzodihydrostilbenes B and D

• Katja Weimann and
• Manfred Braun

Beilstein J. Org. Chem. 2019, 15, 610–616, doi:10.3762/bjoc.15.56

• -D-glucose pentaacetate in the presence of an excess of boron trifluoride etherate [20], a regioselective reaction occurred at the phenolic group in ortho-position to the alkyl side chain to give mono-glycosylated product 12. Chelation of the carbonyl and the neighboring phenolic group by the Lewis

• equipped with a stirring bar and a connection to the combined nitrogen/vacuum line. The flask was charged with dihydrostilbene 9 (330 mg, 1.04 mmol) and β-glucose pentaacetate (814 mg, 2.08 mmol) and closed with a septum. The air in the flask was replaced by nitrogen. Then, dichloromethane (4 mL) and boron

Low-budget 3D-printed equipment for continuous flow reactions

• Jochen M. Neumaier,
• Amiera Madani,
• Thomas Klein and
• Thomas Ziegler

Beilstein J. Org. Chem. 2019, 15, 558–566, doi:10.3762/bjoc.15.50

• reactions as a proof of concept for our hardware and for reactor setup. We first started with the optimization of the synthesis of the commonly used glycosyl donor acetobromo-α-D-glucose 2 under flow conditions. To the best of our knowledge, the preparation of glycosyl bromides under continuous flow

• conditions has not been published so far. For the synthesis of acetobromo glucose we used the reactor R3 (Figure 2) with a total volume of 1.5 mL. We first studied various solvents, reaction times, equivalents of HBr and temperatures for the optimization of the reaction. The best conditions are shown in

• withstood the harsh acidic conditions. Work-up of the reaction mixture and isolation of acetobromo glucose 2 was done by passing the reaction mixture through a CSTR device and two syringes for phase separation [34][35]. The procedure can easily get scaled up and provides for a convenient method for