Host–guest interactions between p-sulfonatocalix[4]arene and p-sulfonatothiacalix[4]arene and group IA, IIA and f-block metal cations: a DFT/SMD study

• Valya K. Nikolova,
• Cristina V. Kirkova,
• Silvia E. Angelova and
• Todor M. Dudev

Beilstein J. Org. Chem. 2019, 15, 1321–1330, doi:10.3762/bjoc.15.131

• cations (La3+) a supramolecular approach with explicit solvent treatment has been applied in the study of the effect of metal hydration on the complexation process. The La3+ binding to the p-sulfonatocalix[4]arene host molecule (now in the metal’s second coordination shell) is still exergonic as evidenced

• calixarenes (with the same repeating units). The sulfur functionalities are stated to provide better metal complexation [3]. Unmodified calixarenes and thiacalixarenes are sparingly soluble, have chemical and thermal stability and act as host molecules as they possess cavities, but their inclusion properties

• of p-sulfonatocalix[4]arene and some inorganic and organic cations in aqueous solution [32]. The predicted ΔG value (relative Gibbs energy) of the complexation between the host calixarene molecule and hydrated La3+ cation (with an average coordination number of water molecules in the first hydration

Bambusuril analogs based on alternating glycoluril and xylylene units

• Tomáš Lízal and
• Vladimír Šindelář

Beilstein J. Org. Chem. 2019, 15, 1268–1274, doi:10.3762/bjoc.15.124

• Tomas Lizal Vladimir Sindelar Department of Chemistry and RECETOX, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic 10.3762/bjoc.15.124 Abstract The glycoluril monomer is a popular building block in supramolecular chemistry as it is used for the synthesis of versatile host molecules

N-doped carbon dots covalently functionalized with pillar[5]arenes for Fe³⁺ sensing

• Jia Gao,
• Ming-Xue Wu,
• Dihua Dai,
• Zhi Cai,
• Yue Wang,
• Wenhui Fang,
• Yan Wang and
• Ying-Wei Yang

Beilstein J. Org. Chem. 2019, 15, 1262–1267, doi:10.3762/bjoc.15.123

• , symmetrical structures, superior host–guest properties, supramolecular assembly characteristics, and versatile functionalities [11][15][16]. Carboxylatopillar[5]arene (CP[5]) is one of the most popular functional pillarenes that has been exploited in many research areas, especially in sensing and detection

Phylogenomic analyses and distribution of terpene synthases among Streptomyces

• Lara Martín-Sánchez,
• Kumar Saurabh Singh,
• Mariana Avalos,
• Gilles P. van Wezel,
• Jeroen S. Dickschat and
• Paolina Garbeva

Beilstein J. Org. Chem. 2019, 15, 1181–1193, doi:10.3762/bjoc.15.115

• growth-promoting bacterium that provides salt tolerance to the halophytic plant Limonium sinense (Plumbaginaceae) [17]. The absence of a geosmin synthase in this bacterium leads us to hypothesise that the role of geosmin may be complemented by the plant host. The only other plant endophyte among the 93

Precious metal-free molecular machines for solar thermal energy storage

• Meglena I. Kandinska,
• Snejana M. Kitova,
• Vladimira S. Videva,
• Stanimir S. Stoyanov,
• Stanislava B. Yordanova,
• Stanislav B. Baluschev,
• Silvia E. Angelova and
• Aleksey A. Vasilev

Beilstein J. Org. Chem. 2019, 15, 1096–1106, doi:10.3762/bjoc.15.106

• fluorescent measurements was used allowing recording of the absorbance spectra during the laser irradiation in the perpendicular direction and immediately after the stop of irradiation. Computational details Equilibrium geometries and intermolecular interaction energies for the host–guest assemblies between

• solvent effect induced by the acetonitrile solvent environment, the equilibrium geometries of the host–guest constituents and complexes were reoptimized considering the PCM (polarizable continuum model) solvent model [31]. The so-called basis set superposition error (BSSE) was not taken into account for

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

• enables them to be effective hosts for a wide range of guest molecules including organic biscarbonyl derivatives, near-infrared dyes, acenes, precious metal halide complexes, trimethylammonium ion-pairs, and saccharides. Keywords: fluorescent dye; host–guest chemistry; hydrogen bonding; hydrophobic

• effect; macrocycles; rotaxane; supramolecular; Review 1. Introduction A large fraction of host–guest chemistry research uses macrocyclic compounds as the host molecules [1][2]. There are several reasons for this circumstance. Macrocycles are often relatively easy to synthesize and they have inherently

• the structure of an effective macrocyclic host must include polar functional groups. In water, association is often driven by the hydrophobic effect which means the interior cavity of an effective macrocyclic host should have sections with non-polar surfaces [3]. A macrocyclic host molecule with an

Fabrication, characterization and adsorption properties of cucurbit[7]uril-functionalized polycaprolactone electrospun nanofibrous membranes

• Changzhong Chen,
• Fengbo Liu,
• Xiongzhi Zhang,
• Zhiyong Zhao and
• Simin Liu

Beilstein J. Org. Chem. 2019, 15, 992–999, doi:10.3762/bjoc.15.97

• engineering [6], energy storage [7], biosensors [8], catalysis [9], and environmental engineering [10]. Various supramolecular host molecules such as cyclodextrins (CDs), calix[n]arenes, and pillar[n]arenes can form host–guest inclusion complexes (ICs) with numerous compounds due to their unique cavity

• present in the molecular structure. Combined with merits of host molecules and electrospun nanofibers, the supramolecular host functionalized nanofibers have been widely reported in recent years as efficient molecular filters and absorbent for the removal of hazardous chemicals or polluting substances. A

• [20] and supramolecular polymer nanofibers based on pillar[5]arene [21] also were prepared by the electrospinning technique. Cucurbit[n]urils (CB[n]s, n = 5–8, 10) are a family of pumpkin-shaped cyclic host molecules containing a hydrophobic cavity surrounded by two identical hydrophilic portals [22

Halogen bonding and host–guest chemistry between N-alkylammonium resorcinarene halides, diiodoperfluorobutane and neutral guests

• Fangfang Pan,
• Mohadeseh Dashti,
• Michael R. Reynolds,
• Kari Rissanen,
• John F. Trant and
• Ngong Kodiah Beyeh

Beilstein J. Org. Chem. 2019, 15, 947–954, doi:10.3762/bjoc.15.91

• , Finland Oakland University, Department of Chemistry, 146 Library Drive, Rochester, Michigan, 48309-4479, USA 10.3762/bjoc.15.91 Abstract Single crystal X-ray structures of halogen-bonded assemblies formed between host N-hexylammonium resorcinarene bromide (1) or N-cyclohexylammonium resorcinarene

• guest inclusion in solution. Keywords: capsule; dimeric assemblies; halogen bonding; host–guest chemistry; resorcinarene salts; X-ray crystallography; Introduction The construction of specific supramolecular assemblies based on the directional non-covalent bonding has been a central goal of

• guests, and the length of the alkyl chain [30][31]. In our previous report, the basic conformation of the host N-hexylammonium resorcinarene bromide (Hex-NARBr) was driven by the incorporation of a 1,4-dioxane guest molecule [32], and the inter-cavitand bridging of DIOFB. The relatively long N

Mechanochemistry of supramolecules

• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2019, 15, 881–900, doi:10.3762/bjoc.15.86

• subcomponent self-assembly of a rigid aromatic linear bisamine, pyridine-2-carboxaldehyde and Fe(II) resulting in the tetrahedral [M4L6]4− cage 25 in water reported by Nitschke [82] was a milestone of supramolecular tetrahedral complex chemistry (Figure 14). The authors have thoroughly explored the host–guest

• (Figure 21a). However, 1,8-dipyridylnaphthalene was used as hydrogen-bond acceptor for the [2 + 2] cycloaddition of fumaric acid derivatives (Figure 21b). In 2017 Purse and co-workers reported the host–guest chemistry of pyrogallo[4]arene (39) hexamers under mechano-milling conditions [94]. A hexameric

• capsule 40 formed through hydrogen-bonding and the cavity was found to be able to encapsulate different organic molecules such as alkanes, acids, amines, etc. The encapsulation of a [2.2]paracyclophane in the cage was achieved by ball milling at 30 Hz (Figure 22) and the host–guest product 40 was verified

Photochemical generation of the 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radical from caged nitroxides by near-infrared two-photon irradiation and its cytocidal effect on lung cancer cells

• Ayato Yamada,
• Manabu Abe,
• Yoshinobu Nishimura,
• Shoji Ishizaka,
• Masashi Namba,
• Taku Nakashima,
• Kiyofumi Shimoji and
• Noboru Hattori

Beilstein J. Org. Chem. 2019, 15, 863–873, doi:10.3762/bjoc.15.84

• described above, nitroxides are not toxic to normal host cells and exhibit toxicity only to tumor cells. Thus, nitroxides are ideal candidates as anticancer therapeutic agents. Based on this knowledge, the cytocidal effect of the radical released from compound 2a on lung cancer cells was tested in vitro, in

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

• complexes [2]. CD derivatives have been increasingly applied in catalysis and biomimetic reactions [3][4] thanks to host–guest interactions and to the non-toxic, chiral skeleton of CDs. More specifically, CDs applied in reactions involving metal catalysis [5], organocatalysis [6] and artificial enzymes [7

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

• -difunctionalization; regioselectivity; Introduction Cyclodextrins (CDs) are cyclic oligomers of α-D-glucopyranose (Figure 1 illustrates the heptamer, β-CD) that have attracted worldwide interest in various fields of applied supramolecular chemistry due to their ability to form host–guest inclusion complexes [1]. A

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

• prey–predator relationship, the common symbiotic organisms in the algae and the soft corals might be the source of these metabolites. In fact, many investigations have proved that [23] numerous natural products are actually produced by microbes and/or microbial interactions with the “host from whence

Polyaminoazide mixtures for the synthesis of pH-responsive calixarene nanosponges

• Antonella Di Vincenzo,
• Antonio Palumbo Piccionello,
• Alberto Spinella,
• Delia Chillura Martino,
• Marco Russo and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2019, 15, 633–641, doi:10.3762/bjoc.15.59

• nanosponge materials with tunable properties. Nanosponges (NSs) [7][8][9][10][11][12][13][14] are hyper-cross-linked polymers or copolymers obtained by reacting supramolecular host species as the monomer units with suitable reticulating agents. Of course, the structural, physical and chemical features of the

• obtained material critically depend on the host monomer and the linker used, on their molar ratio and, in the case of copolymers, on the molar ratio between the parent comonomers. Therefore, by a proper choice of the components, tunability in the properties of the materials obtained can be achieved. In

Design and synthesis of multivalent α-1,2-trimannose-linked bioerodible microparticles for applications in immune response studies of Leishmania major infection

• Chelsea L. Rintelmann,
• Tara Grinnage-Pulley,
• Kathleen Ross,
• Daniel E. K. Kabotso,
• Angela Toepp,
• Anne Cowell,
• Christine Petersen,
• Balaji Narasimhan and
• Nicola Pohl

Beilstein J. Org. Chem. 2019, 15, 623–632, doi:10.3762/bjoc.15.58

• recognition by pathogen-recognition receptors during L. major-induced leishmaniasis. Keywords: adjuvant; carbohydrates; L. major; microparticle; PAMP; Introduction Recognition of parasite cell surface molecules by host immune cells initiates the first step in the immune response [1][2]. The host’s immune

• system recognizes parasite surface glycoconjugates, or pathogen-associated molecular patterns (PAMPs), to build an immune response against the parasite and impede disease progression. Antigen presenting cells (APCs) recognize these PAMPs as pathogenic as compared to host glycans making these moieties

• ). The World Health Organization estimates that this neglected tropical disease causes between 1–2 million new cases annually [4]. Leishmaniasis manifests into three different forms, cutaneous, mucosal, or visceral, depending on parasite species, host immune system and location of infection [5

Back to the future: Why we need enzymology to build a synthetic metabolism of the future

• Tobias J. Erb

Beilstein J. Org. Chem. 2019, 15, 551–557, doi:10.3762/bjoc.15.49

• respect to their complexity (Figure 1), these classical metabolic engineering approaches can be classified as level 1 efforts, i.e., the optimization of a natural pathway in a native organism, or level 2 efforts, i.e., the transplantation or reconstruction of a natural pathway in a new host organism [11

• avoided some problems upfront [58]. Yet, it needs to be mentioned that even if complex synthetic metabolic networks can be realized in vitro, this does not mean that these metabolic networks can be easily transplanted into living cells. The introduction of new reactions and metabolites into a host cell is

• expected to create interactions with the native metabolic and regulatory network of the host. Again, promiscuity poses a major challenge. Even though the metabolites and reactions might be completely non-native to the cell, these intermediates might be still drained due to unwanted side reactions or create

Aqueous olefin metathesis: recent developments and applications

• Valerio Sabatino and
• Thomas R. Ward

Beilstein J. Org. Chem. 2019, 15, 445–468, doi:10.3762/bjoc.15.39

• (Figure 1c) through host–guest interactions [61]. Chung and co-workers used a PEG-tethered adamantyl ligand for various metathesis reactions in water and DCM [62]. The authors showed that the catalyst can be easily removed by generating a host–guest complex between silica-grafted β-cyclodextrin and the

• through host–guest interaction with silica-gel-supported β-cyclodextrin. Selection of artificial metathases reported by Ward and co-workers (ArM 1 based on biotin–(strept)avidin technology and ArM 2 based on dative anchoring to hCAII). Artificial metathase based on covalent anchoring approach. α

Chemical structure of cichorinotoxin, a cyclic lipodepsipeptide that is produced by Pseudomonas cichorii and causes varnish spots on lettuce

• Hidekazu Komatsu,
• Takashi Shirakawa,
• Takeo Uchiyama and
• Tsutomu Hoshino

Beilstein J. Org. Chem. 2019, 15, 299–309, doi:10.3762/bjoc.15.27

• Pseudomonas cichorii causes varnish spots on lettuce. Varnish spots, also called midrib rot or bacterial rot [1][2][3][4], are dark brown and can induce necrotic lesions [1][2][3][4][5][6][7]. P. cichorii, isolated by us, infects a wide range of host plants, including monocot and dicot species (e.g

Fabrication of supramolecular cyclodextrin–fullerene nonwovens by electrospinning

• Hiroaki Yoshida,
• Ken Kikuta and
• Toshiyuki Kida

Beilstein J. Org. Chem. 2019, 15, 89–95, doi:10.3762/bjoc.15.10

• supramolecular fiber materials composed of cyclodextrin (CD)–fullerene inclusion complexes by electrospinning. Similar to the molecular state of fullerenes in solution, the resulting fibers include molecularly-dispersed fullerenes. We believe such a concept could be expanded to diverse host–guest complexes

• functionalize such fibers is to use host–guest inclusion complexes in CD electrospinning. To date, Uyar and Celebioglu have reported electrospinning of two different inclusion complexes: hydroxypropyl-β-CD (HP-β-CD)–tricosan [16] and HP-β-CD–azobenzene inclusion complexes [17]. Although such complexes are

• abilities for free radical scavengers and solar cell applications [18][19][20]. A serious issue for practical applications of fullerenes is the poor solubility in most solvents. Various methods to improve the solubility have been demonstrated by coating the surface with surfactants or host molecules and

Lectins of Mycobacterium tuberculosis – rarely studied proteins

• Katharina Kolbe,
• Sri Kumar Veleti,
• Norbert Reiling and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2019, 15, 1–15, doi:10.3762/bjoc.15.1

• biology and identify new drug targets and anti-Mtb strategies. Mtb bacteria are mainly transmitted by inhalation of aerosolized droplets released from infected patients by coughing. The infection process is initiated by contact between inhaled bacteria and host cells within the alveolar airspace. The main

• invasion of host cells is a complex process, which is initiated by interactions between host and bacterial cell surface structures. As shown in previous studies, host cells can bind to mycobacterial cell wall carbohydrates via a class of surface-localized or secreted proteins known as lectins, and these

• -SIGN) [28][29], the dendritic cell-specific C-type lectins (Dectin-1, Dectin-2) [30][31], the macrophage inducible C-type lectin (Mincle) [32][33][34], the macrophage C-type lectin (MCL) [35][36], and the mannose receptor (MR) [37][38] (Figure 1). Since the importance of host lectins in Mtb infection

Repurposing the anticancer drug cisplatin with the aim of developing novel Pseudomonas aeruginosa infection control agents

• Mingjun Yuan,
• Song Lin Chua,
• Yang Liu,
• Daniela I. Drautz-Moses,
• Joey Kuok Hoong Yam,
• Thet Tun Aung,
• Roger W. Beuerman,
• May Margarette Santillan Salido,
• Stephan C. Schuster,
• Choon-Hong Tan,
• Michael Givskov,
• Liang Yang and
• Thomas E. Nielsen

Beilstein J. Org. Chem. 2018, 14, 3059–3069, doi:10.3762/bjoc.14.284

• induced expression of ptrB, a repressor of T3SS by cisplatin treatment (Supporting Information File 1, Table S3). The T3SS is one of the major virulence mechanisms employed by P. aeruginosa and other microbial pathogens to impair the host immune systems during infection [36][37]. T3SS activity of P

• . aeruginosa was correlated with acute cytotoxicity to host epithelial cells and immune cells such as macrophages and neutrophils [38]. As we demonstrated that cisplatin treatment was able to reduce the T3SS of P. aeruginosa, we further tested the ability of cisplatin in attenuating the acute cytotoxicity of P

MoO₃ on zeolites MCM-22, MCM-56 and 2D-MFI as catalysts for 1-octene metathesis

• Hynek Balcar,
• Martin Kubů,
• Naděžda Žilková and
• Mariya Shamzhy

Beilstein J. Org. Chem. 2018, 14, 2931–2939, doi:10.3762/bjoc.14.272

• cups as we assume host MoOx species. Although MCM-56(13) as 2D zeolite consists of very thin layers, these layers may be curled and packed, which prevents the access of substrate molecules to the most of 12MR cups (for MCM-56(13) morphology see Supporting Information File 1, Figure S8). This may

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

• are other strategies that are being explored towards the discovery of new antibiotics with novel mechanisms of action such as for example inhibitors of host–pathogen interactions and of the type 3 secretion system (T3SS) in Gram-negative bacteria, nonetheless, the specific targets remain unknown or

Enhanced single-isomer separation and pseudoenantiomer resolution of new primary rim heterobifunctionalized α-cyclodextrin derivatives

• Iveta Tichá,
• Gábor Benkovics,
• Milo Malanga and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2018, 14, 2829–2837, doi:10.3762/bjoc.14.261

• ; heterobifunctionalized alpha-cyclodextrin; homobifunctionalized alpha-cyclodextrin; regioisomers; regioselectivity; Introduction Cyclodextrins, cyclic cone-shaped oligosaccharides [1], have long attracted interest for their properties in host–guest complexes both in research and in pharmaceutical and food industry

Synthesis of pyrrolidine-based hamamelitannin analogues as quorum sensing inhibitors in Staphylococcus aureus

• Jakob Bouton,
• Kristof Van Hecke,
• Reuven Rasooly and
• Serge Van Calenbergh

Beilstein J. Org. Chem. 2018, 14, 2822–2828, doi:10.3762/bjoc.14.260

• hypothesized that by “disarming” the pathogen, rather than inhibiting its growth, selective pressure for resistance development will be much lower. Furthermore, reduction of bacterial virulence directly protects the host, and at the same time renders the bacteria more susceptible towards the host defense