6’-Fluoro[4.3.0]bicyclo nucleic acid: synthesis, biophysical properties and molecular dynamics simulations

• Sibylle Frei,
• Andrei Istrate and
• Christian J. Leumann

Beilstein J. Org. Chem. 2018, 14, 3088–3097, doi:10.3762/bjoc.14.288

• structure, giving evidence of mixed A/B-type helices. Molecular modeling To gain more information on the structural features of the 6’F-bc4,3 modification, we performed molecular dynamics simulations of the modified duplexes. We first calculated the potential energy profile versus pseudorotation phase angle

N-Acylated amino acid methyl esters from marine Roseobacter group bacteria

• Hilke Bruns,
• Lisa Ziesche,
• Nargis Khakin Taniwal,
• Laura Wolter,
• Thorsten Brinkhoff,
• Jennifer Herrmann,
• Rolf Müller and
• Stefan Schulz

Beilstein J. Org. Chem. 2018, 14, 2964–2973, doi:10.3762/bjoc.14.276

• spectra often reveal key structural features. Furthermore, the availability of large cross-platform databases useful for dereplication allows focussing on new compounds. We are interested in natural compounds from Roseobacter group bacteria, an abundant class of marine bacteria occurring in diverse

Protein–protein interactions in bacteria: a promising and challenging avenue towards the discovery of new antibiotics

• Laura Carro

Beilstein J. Org. Chem. 2018, 14, 2881–2896, doi:10.3762/bjoc.14.267

• interface in both Gram-negative and Gram-positive microorganisms. In order to encourage prospective drug discovery endeavours in this field, this study focuses on four examples of bacterial PPIs for which inhibitors with promising activities have been reported. For each of the targets the structural

• features of the ligands, the discovery strategy, the characterization assay, the biological activity, and, if applicable, the SAR are discussed. Review Protein–protein interactions Due to the fact that protein–protein interactions (PPIs) play a pivotal role in many cellular processes, they have

The influence of the cationic carbenes on the initiation kinetics of ruthenium-based metathesis catalysts; a DFT study

• Magdalena Jawiczuk,
• Angelika Janaszkiewicz and
• Bartosz Trzaskowski

Beilstein J. Org. Chem. 2018, 14, 2872–2880, doi:10.3762/bjoc.14.266

• carbenes are asymmetric [55][56]. Unfortunately the subtle Wanzlick equilibrium between many saturated carbenes may easily shift to either the dimeric or monomeric form with a small structural change and it is not a trivial task to predict the more stable form of the carbene based solely on its structural

• features. Since all investigated carbenes are asymmetric we considered the possibility of formation of two different dimers, marked A (symmetric) and B (asymmetric), respectively (Table 1). Results obtained for carbenes 1 and 2 suggest a strong preference for both systems to dimerize, with a slightly lower

Microwave-assisted synthesis of biologically relevant steroidal 17-exo-pyrazol-5'-ones from a norpregnene precursor by a side-chain elongation/heterocyclization sequence

• Gergő Mótyán,
• László Mérai,
• Márton Attila Kiss,
• Zsuzsanna Schelz,
• Izabella Sinka,
• István Zupkó and
• Éva Frank

Beilstein J. Org. Chem. 2018, 14, 2589–2596, doi:10.3762/bjoc.14.236

• the sterane framework; (iii) a hydroxy or keto group at C-3 and (iv) the presence of a C16–C17 double bond, which facilitates the inhibitory effect but is not an essential requirement. Some 17-heterocycle-substituted androstanes, even those that lack the structural features described above, are also

Synthesis of a leopolic acid-inspired tetramic acid with antimicrobial activity against multidrug-resistant bacteria

• Luce Mattio,
• Loana Musso,
• Leonardo Scaglioni,
• Andrea Pinto,
• Piera Anna Martino and
• Sabrina Dallavalle

Beilstein J. Org. Chem. 2018, 14, 2482–2487, doi:10.3762/bjoc.14.224

• the plant Juniperus excelsa [3][4]. Leopolic acid A is endowed with antibacterial activity against Staphylococcus aureus and Staphylococcus pseudintermedius with a MIC of 16 μg/mL, and against Escherichia coli with a MIC of 128 µg/mL [3][4]. In terms of structural features, this compound contains a 4

• acid A analogue containing the tetramic acid moiety in place of the 2,3-pyrrolidinone ring (compound 1), while maintaining unchanged all the other structural features of the natural compound. The advantage of this substitution should be a higher stability of the heterocyclic ring, hopefully coupled

Synergistic approach to polycycles through Suzuki–Miyaura cross coupling and metathesis as key steps

• Sambasivarao Kotha,
• Milind Meshram and
• Chandravathi Chakkapalli

Beilstein J. Org. Chem. 2018, 14, 2468–2481, doi:10.3762/bjoc.14.223

• -dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) to generate nitronaphthalene 15 (60%, Scheme 2). Due to their useful biological activity and intricate structural features of angucyclines such as 16–19 (Figure 2), several approaches have been reported for their assembly. In this context, de Koning and co

Determining the predominant tautomeric structure of iodine-based group-transfer reagents by ¹⁷O NMR spectroscopy

• Nico Santschi,
• Cody Ross Pitts,
• Benson J. Jelier and
• René Verel

Beilstein J. Org. Chem. 2018, 14, 2289–2294, doi:10.3762/bjoc.14.203

• solution. After calibration, the approach described herein likely provides a more general and direct method to distinguish between cyclic and acyclic structural features based on a single experimental 17O NMR spectrum and a computationally-derived isotropic shift value. Furthermore, we apply this

Coordination-driven self-assembly of discrete Ru₆–Pt₆ prismatic cages

• Aderonke Ajibola Adeyemo and
• Partha Sarathi Mukherjee

Beilstein J. Org. Chem. 2018, 14, 2242–2249, doi:10.3762/bjoc.14.199

• All efforts to obtain single crystals of the prismatic cages were unsuccessful so far. Thus the structures of 3a and 3b were optimized to get insights into their structural features. The tritopic platinum(II) metalloligand was optimized using the B3LYP method while the heterometallic cage structures

Evaluation of dispersion type metal···π arene interaction in arylbismuth compounds – an experimental and theoretical study

• Ana-Maria Preda,
• Małgorzata Krasowska,
• Lydia Wrobel,
• Philipp Kitschke,
• Phil C. Andrews,
• Jonathan G. MacLellan,
• Lutz Mertens,
• Marcus Korb,
• Tobias Rüffer,
• Heinrich Lang,
• Alexander A. Auer and
• Michael Mehring

Beilstein J. Org. Chem. 2018, 14, 2125–2145, doi:10.3762/bjoc.14.187

• , Professur Anorganische Chemie, 09107 Chemnitz, Germany 10.3762/bjoc.14.187 Abstract The dispersion type Bi···π arene interaction is one of the important structural features in the assembly process of arylbismuth compounds. Several triarylbismuth compounds and polymorphs are discussed and compared based on

• interactions between different structural features balance in order to stabilize molecular arrangements present in the crystal structure. Furthermore, the computational results allow to group this class of compounds into the range of heavy main group element compounds which have been characterized as

• interactions (Bi···π, π···π or C–H···π) is observed and thus leads to different structural features in the solid state (Table 1). Here the question arises how important and how large these interactions are and whether any type of interaction is dominating. For this reason computational studies have been

Water-soluble SNS cationic palladium(II) complexes and their Suzuki–Miyaura cross-coupling reactions in aqueous medium

• Alphonse Fiebor,
• Richard Tia,
• Banothile C. E. Makhubela and
• Henok H. Kinfe

Beilstein J. Org. Chem. 2018, 14, 1859–1870, doi:10.3762/bjoc.14.160

• nature of the backbone on the catalytic activity of the SNS pincer Pd(II) complexes. In the future, efforts to fine tune the electronic and structural features of the thiophenyl and pyridinyl groups will be carried out in order to enable the catalysts to activate aryl chlorides, possessing electron

Enzyme-free genetic copying of DNA and RNA sequences

• Marilyne Sosson and
• Clemens Richert

Beilstein J. Org. Chem. 2018, 14, 603–617, doi:10.3762/bjoc.14.47

• (kcov/khydr), when reacting with an RNA primer. It will not be trivial to find such a leaving group, as the nucleophilicity of alcohols is quite similar to that of water, so that it is difficult to utilize the chemoselectivity toward reaction partners with different softness, pKa, or other structural

• features. Copying on solid support As mentioned above, one option to avoid stalling of primer extension reactions is to perform them on solid support. For RNA, the immobilization of the primer–template duplex was achieved by employing a biotinylated capture strand that was bound to streptavidin-coated

Carbohydrate inhibitors of cholera toxin

• Vajinder Kumar and
• W. Bruce Turnbull

Beilstein J. Org. Chem. 2018, 14, 484–498, doi:10.3762/bjoc.14.34

• particular emphasis on exploiting the multivalency of the toxin to enhance activity. In this review we introduce the structural features of the toxin that have guided the design of diverse inhibitors and summarise recent developments in the field. Keywords: carbohydrate; cholera; multivalency; toxin

5-Aminopyrazole as precursor in design and synthesis of fused pyrazoloazines

• Ranjana Aggarwal and
• Suresh Kumar

Beilstein J. Org. Chem. 2018, 14, 203–242, doi:10.3762/bjoc.14.15

Aminosugar-based immunomodulator lipid A: synthetic approaches

• Alla Zamyatina

Beilstein J. Org. Chem. 2018, 14, 25–53, doi:10.3762/bjoc.14.3

• isolates obtained from bacterial cultures as well as possible contamination with other pro-inflammatory bacterial components makes it difficult to obtain unambiguous immunobiological data correlating specific structural features of lipid A with its endotoxic activity. Advanced understanding of the

• structural homologs having a variable number of the long-chain acyl residues of different chain lengths. The structural heterogeneity of lipid A preparations obtained through LPS isolation from bacterial cultures makes it difficult to get an unbiased correlation of specific structural features of lipid A and

• dependent manner via the action of an oxidase located in the outer membrane [113][114]. The unique Rhizobium lipid A lacks the structural features which are necessary for the TLR4-mediated stimulation of the innate immune system in animals. This might conceivably help bacteroids to evade the innate immune

Binding abilities of a chiral calix[4]resorcinarene: a polarimetric investigation on a complex case of study

• Marco Russo and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2017, 13, 2698–2709, doi:10.3762/bjoc.13.268

• known from the literature as NMR shift reagent able to perform chiral recognition [24][25][26][27]. Guests 1–12 were selected for their diverse structural features. We considered both neutral and ionic species, in particular aliphatic and aromatic cations of different size and hydrophobic character

• M−1). Owing to the diverse behaviours observed, a comparison between the different guests is not straightforward, and a full rationalization of the outcome of their structural features on the binding equilibrium is not simple. Nevertheless, the data allow some further interesting observations. In

Development of a fluorogenic small substrate for dipeptidyl peptidase-4

• Futa Ogawa,
• Masanori Takeda,
• Kanae Miyanaga,
• Keita Tani,
• Ryuji Yamazawa,
• Kiyoshi Ito,
• Atsushi Tarui,
• Kazuyuki Sato and
• Masaaki Omote

Beilstein J. Org. Chem. 2017, 13, 2690–2697, doi:10.3762/bjoc.13.267

• different, ideally, non-fluorescence and intensive fluorescence, respectively. On the basis of the structural features of 1, we expected that its fluorescence would disappear as a result of peptide derivatization of the amino group, because electron donation by the amino group would be attenuated and the

Pyrene–nucleobase conjugates: synthesis, oligonucleotide binding and confocal bioimaging studies

• Artur Jabłoński,
• Yannic Fritz,
• Hans-Achim Wagenknecht,
• Rafał Czerwieniec,
• Tytus Bernaś,
• Damian Trzybiński,
• Krzysztof Woźniak and
• Konrad Kowalski

Beilstein J. Org. Chem. 2017, 13, 2521–2534, doi:10.3762/bjoc.13.249

• are characterized by structural features originated from their components: a planar pyrenyl group and the heterocyclic nucleobase unit. While the pyrenyl group is known to act as intercalator [8][9], the nucleobases are known to self-assemble via a network of hydrogen bonds [16][34]. Our aim was to

Synthesis of ergostane-type brassinosteroids with modifications in ring A

• Vladimir N. Zhabinskii,
• Darya A. Osiyuk,
• Yuri V. Ermolovich,
• Natalia M. Chaschina,
• Tatsiana S. Dalidovich,
• Miroslav Strnad and
• Vladimir A. Khripach

Beilstein J. Org. Chem. 2017, 13, 2326–2331, doi:10.3762/bjoc.13.229

• -, 3-keto-, 3α- and 3β-hydroxy-, 2α-hydroxy-3-keto-) which are characteristic for biosynthetic precursors/metabolites of BS. The 2α,3α-diol function of ergostane BS was shown to be transformable into the required functionalities in only two to four standard chemical transformations. Structural features

Novel approach to hydroxy-group-containing porous organic polymers from bisphenol A

• Tao Wang,
• Yan-Chao Zhao,
• Li-Min Zhang,
• Yi Cui,
• Chang-Shan Zhang and
• Bao-Hang Han

Beilstein J. Org. Chem. 2017, 13, 2131–2137, doi:10.3762/bjoc.13.211

• Information File 1), it can be found that the 13C chemical shifts of these polymers are similar. It is reasonable considering the structural features of these polymers. Typically, taking the spectrum of PPOP-1 for example, two major resonances at 127 and 140 ppm are assigned to the unsubstituted phenyl carbon

Difunctionalization of alkenes with iodine and tert-butyl hydroperoxide (TBHP) at room temperature for the synthesis of 1-(tert-butylperoxy)-2-iodoethanes

• Hao Wang,
• Cui Chen,
• Weibing Liu and
• Zhibo Zhu

Beilstein J. Org. Chem. 2017, 13, 2023–2027, doi:10.3762/bjoc.13.200

• unique structural features, which make them available to serve as starting materials for a wide range of organic oxidations to access other oxygenated products [36]. Results and Discussion A pilot reaction setup comprised of styrene (1a, 208 mg, 2.0 mmol) in the presence of I2 (1.0 equiv), TBHP (2.0

Mechanochemical synthesis of thioureas, ureas and guanidines

• Vjekoslav Štrukil

Beilstein J. Org. Chem. 2017, 13, 1828–1849, doi:10.3762/bjoc.13.178

• , mechanochemistry has been demonstrated as an effective tool in reaction discovery, with emphasis on the reactivity differences in solution and in the solid state. These three classes of organic compounds share some structural features which are reflected in their physical and chemical properties, important for

The chemistry and biology of mycolactones

• Matthias Gehringer and
• Karl-Heinz Altmann

Beilstein J. Org. Chem. 2017, 13, 1596–1660, doi:10.3762/bjoc.13.159

• toxin. III. Total synthesis of mycolactones The fascinating biology and the challenging structural features of mycolactones have attracted significant interest from research groups worldwide with a focus on natural product synthesis. In this chapter the synthetic work on mycolactones that has been

Glycoscience@Synchrotron: Synchrotron radiation applied to structural glycoscience

• Serge Pérez and
• Daniele de Sanctis

Beilstein J. Org. Chem. 2017, 13, 1145–1167, doi:10.3762/bjoc.13.114

• , the double helices have a radial orientation, and are perpendicular to the surface of the granule. At the resolution of these ultra-structural features (10 µm) there is no discontinuity of orientation, i.e., no disclination of orientation. Between 10 µm steps, the change of the direction of the double

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

• characterization should be performed in order to fully describe such systems. We showed that understanding of molecular level structural features of such complex mixtures (free CDs, homopolymers, CD-oligoesters) have to take into consideration the mass spectrometry methods in direct correlation with the NMR