Aqueous semisynthesis of C-glycoside glycamines from agarose

• Juliana C. Cunico Dallagnol,
• Alexandre Orsato,
• Diogo R. B. Ducatti,
• Miguel D. Noseda,
• Maria Eugênia R. Duarte and
• Alan G. Gonçalves

Beilstein J. Org. Chem. 2017, 13, 1222–1229, doi:10.3762/bjoc.13.121

• recently envisaged that its substituted C-threofuranose ring could serve as an excellent scaffold to build muscarine analogues [11]. Cholinergic agents targeting muscarinic acetylcholine receptors (mAChRs) have historically served for diverse applications in medicine [12][13] and recently regained interest

From chemical metabolism to life: the origin of the genetic coding process

• Antoine Danchin

Beilstein J. Org. Chem. 2017, 13, 1119–1135, doi:10.3762/bjoc.13.111

• their environment. For example, there are receptors for taste with exquisite recognition of specific molecules, sugars for example. The sweet taste is triggered by a lock-and-key process in which sugars fit within a specific cavity of the receptor. This interaction can be mimicked by compounds that have

G-Protein coupled receptors: answers from simulations

• Timothy Clark

Beilstein J. Org. Chem. 2017, 13, 1071–1078, doi:10.3762/bjoc.13.106

• the modes of action of G-protein coupled receptors (GPCRs). In this field, MD simulations are unusually important as, because of the difficult experimental situation, they often offer the only opportunity to determine structural and mechanistic features in atomistic detail. Modern combinations of soft

• with what is already available, it reuses successful designs again and again in slightly modified forms. This is the case for the most common means of communicating across cell walls in eukaryotes, G-protein coupled receptors (GPCRs). GPCRs span the cell membrane and generally complex switching ligands

• G-Protein Coupled Receptor” [2]. Their functions are myriad, from olfactory and visual receptors to pure signaling systems that govern cell function. Malfunction of GPCRs is prevalent in human diseases, so that approximately half (estimates vary between 30 and 60%) of marketed drugs target GPCRs

Glyco-gold nanoparticles: synthesis and applications

• Federica Compostella,
• Olimpia Pitirollo,
• Alessandro Silvestri and
• Laura Polito

Beilstein J. Org. Chem. 2017, 13, 1008–1021, doi:10.3762/bjoc.13.100

• containing mannose-binding receptors) [46] and thyroglobulin in serum [47] and to study the internalization pathway in dendritic cells, employing confocal laser microscopy (CLSM) and flow cytometry [48]. Moreover, even techniques based on light scattering, like dark field microscopy (DFM), resulted

• glucose and galactose moieties multi-displayed on gold surface acted as target for asialoglycoprotein receptors, over-expressed on liver cancer cells, delivering selectively the anticancer drug Au(I). In search of novel antimicrobial antigens, chitosan-streptomycin GAuNPs (CA NPs), i.e., carbohydrate

• mice, the authors demonstrated that GAuNPs selectively targeted overexpressed glucose receptors (GLUT1) and accumulated in the damaged lung, while PEGylated AuNPs did not show any relevant accumulation in the inflammation site. Moreover, another study on the synthesis of glucose-functionalized AuNPs

A strategic approach to [6,6]-bicyclic lactones: application towards the CD fragment of DHβE

• Tue Heesgaard Jepsen,
• Emil Glibstrup,
• François Crestey,
• Anders A. Jensen and
• Jesper Langgaard Kristensen

Beilstein J. Org. Chem. 2017, 13, 988–994, doi:10.3762/bjoc.13.98

• pharmacological evaluations support the notion that the key pharmacophores of DHβE are located in the A and B rings. Keywords: DhβE; Mizoroki–Heck cross-coupling reaction; 6π-electrocyclization; [6,6]-bicyclic lactone; vinyl halide; Introduction The neuronal nicotinic acetylcholine receptors (nAChRs) have been

Pd- and Cu-catalyzed approaches in the syntheses of new cholane aminoanthraquinone pincer-like ligands

• Nikolay V. Lukashev,
• Gennadii A. Grabovyi,
• Dmitry A. Erzunov,
• Alexey V. Kazantsev,
• Gennadij V. Latyshev,
• Alexei D. Averin and
• Irina P. Beletskaya.

Beilstein J. Org. Chem. 2017, 13, 564–570, doi:10.3762/bjoc.13.55

• multiple steps and is tedious, and the macrocyclization step generally provides low to moderate yields. Moreover, subsequent modification of these molecules for tuning their solubility or binding ability is often difficult. Consequently, the idea of molecular pockets or jellyfish resembling receptors with

• transport of anions through lipid membranes [19][20][21][22]. Some of similar pincer compounds can be used as receptors for organic molecules; e.g., polyamino derivatives based on cholane skeleton can form complexes with amino acids [23] and pincer-like conjugates of deoxycholic acid and aminopyrene can

• jellyfish resembling receptors (b) [11][16]. UV–vis spectra of 5c (50 μM solution in MeCN) before and after the addition of 5 equiv of metal perchlorates. Example of Pd-catalyzed amination for modification of bile acid derivatives. Synthesis of 24-aminocholanols. Synthesis of 24-arylaminocholanols by Cu

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

• activity [12]. Remarkable, however, is the inactivity of the (2R)-isosarcophytoxide (11) up to 2% of dry pellet mass, a mere stereoisomer of the active metabolite 10. Such a dependence on stereochemistry may result from a specific interaction with taste receptors in C. solandri lips, oral cavity and

• pharyngeal part. The importance of stereochemistry for taste response was shown in studies using alanine as a ligand for taste receptors from fish [61][62]. Investigations on the effects of cembranoid diterpenes on receptors are published, e.g., nicotinic receptors by Ferchmin et al. [63]. An important

Synthesis of 1-indanones with a broad range of biological activity

• Marika Turek,
• Dorota Szczęsna,
• Marek Koprowski and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48

• ]. Next, the latter was converted to 4,6-dibromo-5-hydroxy-1-indanone in the presence of a Lewis acid and then transformed to 5-hydroxy-1-indanone as a result of debromination. Adrenergic receptors are metabotropic receptors located on cell membranes and stimulated by catecholamines, especially adrenaline

Spectral and DFT studies of anion bound organic receptors: Time dependent studies and logic gate applications

• Srikala Pangannaya,
• Neethu Padinchare Purayil,
• Shweta Dabhi,
• Venu Mankad,
• Prafulla K. Jha,
• Satyam Shinde and
• Darshak R. Trivedi

Beilstein J. Org. Chem. 2017, 13, 222–238, doi:10.3762/bjoc.13.25

• Krishnakumarsinhji Bhavnagar University, Bhavnagar 364001, India Department of Physics, Faculty of Science, The M.S. University of Baroda, Vadodara 390002, India School of Technology, Pandit Deendayal Petroleum University, Gandhinagar 382007, Gujarat, India 10.3762/bjoc.13.25 Abstract New colorimetric receptors R1

• and R2 with varied positional substitution of a cyano and nitro signaling unit having a hydroxy functionality as the hydrogen bond donor site have been designed, synthesized and characterized by FTIR, 1H NMR spectroscopy and mass spectrometry. The receptors R1 and R2 exhibit prominent visual response

• . Keywords: colorimetric sensor; DFT; molecular logic gates; rate constant; substituent effect; Introduction The development of new organic receptors for the detection of anions is of key interest to supramolecular chemists owing to the biological and environmental importance of anions [1][2][3][4][5][6][7

Synthesis of acylhydrazino-peptomers, a new class of peptidomimetics, by consecutive Ugi and hydrazino-Ugi reactions

• Angélica de Fátima S. Barreto,
• Veronica Alves dos Santos and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2016, 12, 2865–2872, doi:10.3762/bjoc.12.285

• cancer therapeutics for being an antagonist of the vascular endothelial growth factor receptor 2 [13]; peptoid 2 is a ligand of the protooncogene Crk [14]; and peptoids 3 and 4 showed a high affinity for the α1-adrenergic and μ-specific opiate receptors [15], respectively (Figure 2). Unlike peptides, in

• effect on the physical properties of a peptide as well as on its structural characteristics. The semicarbazide constraints tend to facilitate interactions with protein receptors due to turn geometry within the azapeptide. As a result, their stability over enzymes and chemical degradation may be enhanced

New approaches to organocatalysis based on C–H and C–X bonding for electrophilic substrate activation

• Pavel Nagorny and
• Zhankui Sun

Beilstein J. Org. Chem. 2016, 12, 2834–2848, doi:10.3762/bjoc.12.283

• acceptors and also act as electron-withdrawing substituents when attached to other aromatic rings thus enhancing benzene’s ring C–H hydrogen bonding [29][30][31]. Recent studies by the Flood group and the Craig group suggested that receptors containing arylated 1,2,3-triazoles could form stable

• supramolecular complexes with anions [32][33][34]. The stability of such complexes correlated with the number of C–H bonds that could be formed by the receptor, and strong binding comparable to the more traditional X–H bonding based hydrogen bond donors was observed for the receptors forming 5–9 hydrogen bonds

O-Alkylated heavy atom carbohydrate probes for protein X-ray crystallography: Studies towards the synthesis of methyl 2-O-methyl-L-selenofucopyranoside

• Roman Sommer,
• Dirk Hauck,
• Annabelle Varrot,
• Anne Imberty,
• Markus Künzler and
• Alexander Titz

Beilstein J. Org. Chem. 2016, 12, 2828–2833, doi:10.3762/bjoc.12.282

• are used as reactive glycosyl donors in the syntheses of oligosaccharides. In addition, such heavy atom analogs of natural glycosides are useful tools for structure determination of their lectin receptors using X-ray crystallography. Some lectins, e.g., members of the tectonin family, only bind to

• isolated after Zemplén deprotection in 99% yield and a ratio of α/β = 5:1. Conclusion Unsubstituted seleno glycosides are used for structure determination of complexes with protein receptors. The synthesis of O-methylated analogs has been not reported to date, despite their importance for many lectins. The

Symmetry-based approach to oligostilbenoids: Rapid entry to viniferifuran, shoreaphenol, malibatol A, and diptoindonesin G

• Youngeun Jung,
• Dileep Kumar Singh and
• Ikyon Kim

Beilstein J. Org. Chem. 2016, 12, 2689–2693, doi:10.3762/bjoc.12.266

• estrogen receptors (ER) has been discovered, thereby suggesting it as a promising drug lead for the treatment of breast cancer [18]. Our continuing interest in this area led us to design an alternative approach to oligostilbenoids. As shown in Scheme 1, our idea stemmed from recognition of the symmetry

Interactions between cyclodextrins and cellular components: Towards greener medical applications?

• Loïc Leclercq

Beilstein J. Org. Chem. 2016, 12, 2644–2662, doi:10.3762/bjoc.12.261

• of pentapeptides to α- and β-CD [88]. The two peptides used in this study were: Tyr-Ile-Gly-Ser-Arg (YIGSR) and Tyr-Gly-Gly-Phe-Leu (YGGFL). The former interacts specifically with the integrin receptors on specific neuronal cells whereas the latter is known to bind to brain receptor sites. From

• times sweeter than sucrose. Thaumatin has been shown to bind to G-protein-coupled receptors (GPCRs) which are transmembrane proteins, responsible for signal transduction. Therefore, the interaction of CDs with thaumatin could be used to modify the interaction of thaumatin with GPCRs and to modify its

• ) through interactions with several receptors and ABCA1 for HDL and ApoA-I, respectively. However, the process, which leads to an aberrant accumulation of cholesterol in artery walls forming atherosclerotic plaques, is complex. Thus the alteration of RCT as well as the expression and the functionality of

From supramolecular chemistry to the nucleosome: studies in biomolecular recognition

• Marcey L. Waters

Beilstein J. Org. Chem. 2016, 12, 1863–1869, doi:10.3762/bjoc.12.175

• -translational modifications such as trimethyllysine are antibodies, but antibodies have significant limitations in this context, as they are too sequence specific. Thus, we aimed to develop synthetic receptors that would mimic the binding pockets of proteins to recognize trimethyllysine, but not the surrounding

• sequence. This turned out to be an ideal problem to address using DCC, and we have now developed a number of synthetic receptors for methylated lysine and arginine that have applications as sensors for these modifications (Figure 6). Lessons learned As a child, my parents said that I “marched to my own

• interests. (a) Cyclophane receptors from Dennis Dougherty’s group in the late ‘80’s and early ‘90’s that demonstrated cation–π interactions [2]. (b) Cyclophane receptors from the Diederich group in the late ‘80’s and early ‘90’s that demonstrated the “nonclassical hydrophobic effect” [3]. (c) The Hunter

Amidofluorene-appended lower rim 1,3-diconjugate of calix[4]arene: synthesis, characterization and highly selective sensor for Cu²⁺

• Rahman Hosseinzadeh,
• Mohammad Nemati,
• Reza Zadmard and
• Maryam Mohadjerani

Beilstein J. Org. Chem. 2016, 12, 1749–1757, doi:10.3762/bjoc.12.163

• environmental pollutant or an essential trace element in human body – is a great challenge and the development of synthetic receptors based on organic ligands for the detection of Cu2+ seems to be necessary [13]. Accordingly, during the last decades, synthesis and modification of chemosensors based on

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

• multistep synthesis of cannabinergic lactones from dimethylheptylresorcinol. Two regioisomeric cannabinergic lactones were obtained, one of which possessed pronounced affinity towards the CB1 receptor and lower affinities for mCB2 and hCB2 receptors [228]. Oxidation with H2O2–acid systems: With in situ

Organic chemistry meets polymers, nanoscience, therapeutics and diagnostics

• Vincent M. Rotello

Beilstein J. Org. Chem. 2016, 12, 1638–1646, doi:10.3762/bjoc.12.161

• external regulation [4]. I also took on a brutal project, focused on the synthesis of water-soluble analogs of Kemp's triacid. This project was a massive effort, with a huge number of reactions required to optimize the initial steps. We did, however, obtain the desired receptors and observe some

Creating molecular macrocycles for anion recognition

• Amar H. Flood

Beilstein J. Org. Chem. 2016, 12, 611–627, doi:10.3762/bjoc.12.60

• . Keywords: anion receptors macrocycles self-assembly surface architectures switches; Review “Well, maybe it started that way. As a dream, but doesn’t everything. Those buildings. These lights. This whole city. Somebody had to dream about it first. And maybe that is what I did. I dreamed about coming here

• program the outsides of macrocycles to direct 3D packing. Crescent receptors Crescent receptors, while not as elegant as macrocycles, are succinct models for testing ideas. Over the years (Figure 18), we have tested intramolecular hydrogen bonding for preorganization (19) [38], new CH hydrogen bonding

• crescents linked together into oligomers with interesting dynamic shapes. Foldameric anion receptors Complementing our creation and study of macrocycles is work on foldamers (Figure 19). With their flexibility, foldamers are excellent “character foils” to rigid macrocycles. As a class of compounds

Recent advances in N-heterocyclic carbene (NHC)-catalysed benzoin reactions

• Rajeev S. Menon,
• Akkattu T. Biju and
• Vijay Nair

Beilstein J. Org. Chem. 2016, 12, 444–461, doi:10.3762/bjoc.12.47

• 36. The aldehydes function as the acyl donor and the imines behave as the receptors (Scheme 21). Addition of NHC to the highly electrophilic N-Boc imines leads to the formation of corresponding aza-Breslow intermediates; however, it is reversible under the reaction conditions. Importantly, the

Effective in silico prediction of new oxazolidinone antibiotics: force field simulations of the antibiotic–ribosome complex supervised by experiment and electronic structure methods

• Jörg Grunenberg and
• Giuseppe Licari

Beilstein J. Org. Chem. 2016, 12, 415–428, doi:10.3762/bjoc.12.45

• pocket for the oxazolidinone ring is characterized by universally conserved 23S-rRNA nucleotides, leading to very similar ligand-bound conformations in different bacterial ribosomes [23]. From a theoretical point of view, the simulation of recognition processes employing nucleotide-based receptors is

Self and directed assembly: people and molecules

• Tony D. James

Beilstein J. Org. Chem. 2016, 12, 391–405, doi:10.3762/bjoc.12.42

• group were developing carbohydrate receptors from what looked like simple molecules requiring just one or two steps to synthesize. Therefore, while working with the late Takaaki Harada, we developed a simple colorimetric system able to “read-out” the chirality of sugars. The system we developed used the

• these collaborative research projects with Japan, myself and Seiji Shinkai as team leaders were awarded a Daiwa-Adrian Prize in 2013 [36] for “Chemonostics: Using chemical receptors in the development of simple diagnostic devices for age-related diseases” with a team including Steven Bull (University of

• /boronic acid moiety as the acceptor (the reverse is true for normal a-PET systems). Therefore, d-PET systems have a significant advantage over the a-PET systems at acidic pH, since background emission for these sensors is much lower. This is particularly important given that we were developing receptors

Art, auto-mechanics, and supramolecular chemistry. A merging of hobbies and career

• Eric V. Anslyn

Beilstein J. Org. Chem. 2016, 12, 362–376, doi:10.3762/bjoc.12.40

• the creation of synthetic receptors and self-assembly. For synthetic ease, the receptors and assemblies routinely possess a high degree of symmetry, which lends them an aspect of aesthetic beauty. Pictures of electron orbitals similarly can be seen as akin to works of art. This similarity was an early

• responses from a suite of receptors and creates patterns for diagnostic purposes that are beyond what can be achieved by the separate components alone. In fact, we are currently working to push this even further creating multicomponent cascades of reactions yielding a final result that the individual

• group created some of the earliest reported monosaccharide receptors (4) that exploited hydrogen bonding based recognition in chloroform [39][40]. The receptor designs from Hamilton (5) [41] and Thummel (6) [42] at around the same period of time clearly influenced my own designs. This was approximately

Enabling technologies and green processes in cyclodextrin chemistry

• Giancarlo Cravotto,
• Marina Caporaso,
• Laszlo Jicsinszky and
• Katia Martina

Beilstein J. Org. Chem. 2016, 12, 278–294, doi:10.3762/bjoc.12.30

• versatile receptors for molecular recognition and building blocks for functional materials. Due to the binding of two adjacent CD units, bridged bis-CDs display high binding abilities and molecular selectivities compared to native and monosubstituted CDs. A well-organized pseudo-cavity may be provided by

Bright molecules for sensing, computing and imaging: a tale of two once-troubled cities

• A. Prasanna de Silva

Beilstein J. Org. Chem. 2015, 11, 2774–2784, doi:10.3762/bjoc.11.298

• concentration, knocks out a PET pathway from its corresponding receptor to the lumophore. Even a single PET pathway disables emission. Selective receptors were the key. It is perhaps worth noting that a simple expansion of the 'lumophore–spacer–receptor’ system, with the attachment of an additional spacer and