Synthesis of new p-tert-butylcalix[4]arene-based polyammonium triazolyl amphiphiles and their binding with nucleoside phosphates

• Vladimir A. Burilov,
• Guzaliya A. Fatikhova,
• Mariya N. Dokuchaeva,
• Ramil I. Nugmanov,
• Diana A. Mironova,
• Pavel V. Dorovatovskii,
• Victor N. Khrustalev,
• Svetlana E. Solovieva and
• Igor S. Antipin

Beilstein J. Org. Chem. 2018, 14, 1980–1993, doi:10.3762/bjoc.14.173

• /bjoc.14.173 Abstract The synthesis of new calix[4]arenes adopting a cone stereoisomeric form bearing two or four azide fragments on the upper rim and water-soluble triazolyl amphiphilic receptors with two or four polyammonium headgroups via copper-catalyzed azide–alkyne cycloaddition reaction has been

• ]. Calixarenes are easily functionalized at both their upper and lower rims with various stereoisomers obtainable; the initial macrocycles can be synthesized in a simple manner, they are not toxic, etc. [17][18][19][20][21][22]. Amphiphilic calixarenes are particularly interesting because they can be regarded as

• high affinity to ATP [26]. Herein we report the synthesis of new amphiphilic water-soluble calix[4]arene derivatives with cone conformation containing two or four polyammonium groups on the upper rim by using a click chemistry approach and the results of binding studies toward nucleotides in aqueous

An amphiphilic pseudo[1]catenane: neutral guest-induced clouding point change

• Tomoki Ogoshi,
• Tomohiro Akutsu and
• Tada-aki Yamagishi

Beilstein J. Org. Chem. 2018, 14, 1937–1943, doi:10.3762/bjoc.14.167

• /hydrophilic ratio in a molecule largely affects its assembled properties in aqueous media. In this study, we synthesized a new bicyclic compound which could dynamically change its hydrophobic/hydrophilic ratio by chemical stimulus. The bicyclic compound consisted of amphiphilic pillar[5]arene and hydrophobic

• aggregation of the hydrophobic alkyl chain rings, which induced insolubilization of the bicyclic compound in aqueous media at 20 °C and a decrease in its clouding point. Keywords: amphiphilic molecules; host–guest complexes; lower critical solution temperature; pillar[n]arenes; pseudo[1]catenane

• –guest chemistry [5][6][7]. The molecules consist of a non-ionic amphiphilic part containing tri(ethylene oxide) moieties, and a hydrophobic part consisting of a pillar[n]arene core (Figure 1a; 1, n = 5; 2, n = 6). Pillar[n]arenes, which were first reported by our group [11], were used as the macrocyclic

Design, synthesis and structure of novel G-2 melamine-based dendrimers incorporating 4-(n-octyloxy)aniline as a peripheral unit

• Cristina Morar,
• Pedro Lameiras,
• Attila Bende,
• Gabriel Katona,
• Emese Gál and
• Mircea Darabantu

Beilstein J. Org. Chem. 2018, 14, 1704–1722, doi:10.3762/bjoc.14.145

• Background: 4-(n-Octyloxy)aniline is a known component in the elaboration of organic materials with mesogenic properties such as N-substituted Schiff bases, perylene bisimide assemblies with a number of 2-amino-4,6-bis[4-(n-octyloxy)phenylamino]-s-triazines, amphiphilic azobenzene-containing linear-dendritic

• (ethynyl)-s-triazine and various icosanyloxyphenylazides) with liquid crystalline and luminescent properties [22]. On the other hand, mesogenic supramolecular perylene bisimide assemblies with a number of 2-amino-4,6-bis[(4-alkoxy)phenylamino]-s-triazines [23], amphiphilic azobenzene-containing linear

Nanoreactors for green catalysis

• M. Teresa De Martino,
• Loai K. E. A. Abdelmohsen,
• Floris P. J. T. Rutjes and
• Jan C. M. van Hest

Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61

• section we will discuss the utility of some of the well-established catalytic nanoreactors towards green(er) chemistry [62]. 2.1. Micelles Micelles are supramolecular architectures that are assembled of amphiphilic molecules [41]. Above the critical micellar concentration (CMC), surfactants with the

• effect for hydrophobic substrates, which ensures higher reaction rates than those performed in bulk [63]. Besides, the structure of any micellar catalytic environment is governed by the arrangement of the amphiphilic molecules, creating, in many cases, a regioselective environment (Figure 1) that affects

• is occurring in the lipophilic pocket and not in water. The authors also demonstrated the ability of the PQS system to be recycled up to 10 times without loss in its catalytic activity. Catalytic micelles were also prepared by O’Reilly et al. when a novel amphiphilic Sulfur–Carbon–Sulfur (SCS) pincer

Aminosugar-based immunomodulator lipid A: synthetic approaches

• Alla Zamyatina

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

• cytokines, chemokines, prostaglandins and reactive oxygen species which manifest an acute inflammatory response to infection. The “endotoxic principle” of LPS resides in its amphiphilic membrane-bound fragment glycophospholipid lipid A which directly binds to the TLR4·MD-2 receptor complex. The lipid A

• -hydrophobic labeling reagents for amphiphilic glycoconjugates such as lipid A. 1.4. Synthesis of Helicobacter pylori Kdo-lipid A substructures A Helicobacter pylori infection of the gastric mucosa causes chronic gastritis in humans and plays a pivotal role in the progression and pathogenesis of peptic ulcer

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

• occurring in host–guest complex formation processes involving calixarenes in general. This can be particularly useful, even because CAP and structurally related ligands might find various interesting applications, due to their amphiphilic character, chirality and coordination ability towards metal cations

Phosphonic acid: preparation and applications

• Charlotte M. Sevrain,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2017, 13, 2186–2213, doi:10.3762/bjoc.13.219

• phosphonic acid function and its ability to be ionized in water render this group attractive to design the polar head group of anionic amphiphilic compounds [25][26] or polymeric-based amphiphilic derivatives [27]. This type of compound was used as surfactant to stabilize colloidal solutions of nanocrystals

• using bromotrimethylsilane followed by methanolysis. This two-step methodology (1. BrSiMe3; 2. MeOH or H2O) was also applied to prepare macromolecules functionalized with phosphonic acid functional groups. For instance, a cyclodextrine derivative (compound 60 [177], Figure 19), amphiphilic compounds

Superstructures with cyclodextrins: Chemistry and applications IV

• Gerhard Wenz

Beilstein J. Org. Chem. 2017, 13, 2157–2159, doi:10.3762/bjoc.13.215

• , buckminsterfullerene C60 was covalently linked to two γ-CD rings [14]. This conjugate is highly soluble in water because it forms a sandwich-like self-complex, which makes it particularly useful as a sensitizer for singlet oxygen 1O2 generation [14]. Amphiphilic CD derivatives with oligoethylene oxide side chains form

• ]. The group of Ravoo also conjugated arylazopyrazoles to amphiphilic cyclodextrin derivatives that form vesicles triggered by light [17]. A star-shaped polycationic CD derivative with many breakable, intrinsic, disulfide linkages forms nanoparticles with messenger RNA and drugs and is particularly

Chemical systems, chemical contiguity and the emergence of life

• Terrence P. Kee and
• Pierre-Alain Monnard

Beilstein J. Org. Chem. 2017, 13, 1551–1563, doi:10.3762/bjoc.13.155

• association with the interface of chemical systems. For instance, the activity of an RNA polymerase ribozyme was improved when the various RNA compounds of the system (the ribozyme, the template/primer) were derivatized with amphiphilic moieties and co-associated within micelle structures [69]. Although no

• ]. Such vesicles with associated ribozymes could eventually prove to be novel functional chemical systems. The production of fatty acids from non-amphiphilic picolylesters performed using a photochemical reaction involving a ruthenium tris(bipyridine), functioning as photosensitizer and redox catalyst

• -existing structures [94][95] has been experimentally exploited either by adding more amphiphiles at a pace that prevents the de novo formation of novel structures [17] or by adding amphiphile precursors that had to be converted within the structures into amphiphilic molecules themselves [83][96][97

2-Methyl-2,4-pentanediol (MPD) boosts as detergent-substitute the performance of ß-barrel hybrid catalyst for phenylacetylene polymerization

• Julia Kinzel,
• Daniel F. Sauer,
• Marco Bocola,
• Marcus Arlt,
• Tayebeh Mirzaei Garakani,
• Andreas Thiel,
• Klaus Beckerle,
• Tino Polen,
• Jun Okuda and
• Ulrich Schwaneberg

Beilstein J. Org. Chem. 2017, 13, 1498–1506, doi:10.3762/bjoc.13.148

• rhodium-based biohybrid catalyst. Unlike commonly used detergents such as sodium dodecyl sulfate or polyethylene polyethyleneglycol, MPD does not form micelles in solution. Molecular dynamics simulations revealed the effect and position of stabilizing MPD molecules. The advantage of the amphiphilic MPD

• over micelle-forming detergents is demonstrated in the polymerization of phenylacetylene, showing a ten-fold increase in yield and increased molecular weights. Keywords: amphiphilic molecule 2-methyl-2,4-pentanediol; hybrid catalyst; phenylacetylene polymerization; refolding agents; transmembrane

• hydrophobic micelle core. Recently, the small amphiphilic alcohol 2-methyl-2,4-pentanediol (MPD) was shown to successfully stabilize membrane proteins and enable characterization of protein modifications [33][34]. Polymerization of phenylacetylene in the presence of MPD molecules as refolding agent was

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

• offers another example of difficulty in terms of single crystal growth. Glycolipids (or lipo-oligosaccharides) comprise a carbohydrate moiety covalently linked to a lipid that confers on them an amphiphilic character, which makes them reluctant to crystallize. One member of the family is tricolorin A (L

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

• function associated to this view is that the cell separates between an inside and an outside. In 1935, James Danielli proposed with Hugh Davson that this embodiment was achieved by formation of a bilayer made of amphiphilic lipid molecules [11]. This process is entropy-driven (life belongs to physics, it

Correlation of surface pressure and hue of planarizable push–pull chromophores at the air/water interface

• Frederik Neuhaus,
• Fabio Zobi,
• Gerald Brezesinski,
• Marta Dal Molin,
• Stefan Matile and
• Andreas Zumbuehl

Beilstein J. Org. Chem. 2017, 13, 1099–1105, doi:10.3762/bjoc.13.109

• is a structural similarity between the flipper probes and cholesterol with both molecules being amphiphilic and flat. This called for a closer look at the influence of both molecules on phospholipid membrane organization (see Figure 4). For DPPC, the first-order phase transition between the

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

• thio-amphiphilic linker to impart improved solubility and flexibility to the glycosyl-ligand. UV–vis spectroscopy and dynamic light scattering measurements have been exploited to detect at low picomolar concentrations lactose-AuNP, mannose-AuNP and GlcNAc-AuNP interactions with their cognate lectins

• peanut agglutinin [25]. In this case, the glycosyl residue is not coated on the gold surface by means of a thiol moiety but exploiting the strain-promoted azide–alkyne cycloaddition (SPAAC) to covalently link an azido galactoside on a lipid cyclooctyne. In this manner, the amphiphilic glyco-lipid can be

Aggregation behaviour of a single-chain, phenylene-modified bolalipid and its miscibility with classical phospholipids

• Simon Drescher,
• Vasil M. Garamus,
• Christopher J. Garvey,
• Annette Meister and
• Alfred Blume

Beilstein J. Org. Chem. 2017, 13, 995–1007, doi:10.3762/bjoc.13.99

• behaviour; nanofibres; self-assembly; Introduction Bolalipids are amphiphilic molecules consisting of two hydrophilic headgroups attached to both ends of a long hydrocarbon spacer [1]. The hydrophobic spacer is composed of either a single alkyl chain or two chains connected via a glycerol moiety. These

• DPPC/DHPC systems [49], or for mixtures of phospholipids with other amphiphilic substances, e.g., in PEG-stabilized bilayer systems [50][51], for phospholipids with membrane scaffold proteins [52][53] or in combination with copolymers [54][55], or for DPPC in mixture with a T-shaped amphiphile [56

Lipids: fatty acids and derivatives, polyketides and isoprenoids

• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2017, 13, 793–794, doi:10.3762/bjoc.13.78

• , sphingolipids and glycolipids. Lipids also constitute important post-translational protein modifications in lipoproteins. The amphiphilic nature of compounds such as phospholipids with a polar headgroup and a long apolar chain results in the spontaneous formation of lipid bilayers in aqueous environments. This

Conjecture and hypothesis: The importance of reality checks

• David Deamer

Beilstein J. Org. Chem. 2017, 13, 620–624, doi:10.3762/bjoc.13.60

• ]. There are several advantages to using evaporation in this regard. First, simply concentrating potential reactants adds significant free energy to a system that can be used to drive condensation reactions [23]. Furthermore, if amphiphilic compounds are present they can organize and concentrate reactants

• metabolism and polymerization. Products of reactions should accumulate within the site rather than dispersing into the bulk phase environment. Biologically relevant polymers are synthesized with chain lengths sufficient to act as catalysts or incorporate genetic information. If amphiphilic compounds are

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

• complexes with various biomolecules including lipids, carbohydrates, proteins and nucleic acids. In this section, some biomolecule/CD inclusion complexes are presented. i) Complexation of lipids and consequences Lipids are hydrophobic or amphiphilic molecules very diverse, including, among other fats, waxes

• , sterols, fat-soluble vitamins, phospholipids, mono-, di- and triglycerides, etc. Their amphiphilic nature causes the molecules of certain lipids to organize into liposomes when they are in aqueous medium. This property allows the formation of biological membranes. Indeed, cells and organelles membranes

• prenols, which are produced from condensation of isoprene units [54]. These compounds can be easily included inside the CDs because they are hydrophobic or amphiphilic molecules. As mentioned earlier, and as it will become exceeding clear throughout the following sections, the majority of research

A self-assembled cyclodextrin nanocarrier for photoreactive squaraine

• Ulrike Kauscher and
• Bart Jan Ravoo

Beilstein J. Org. Chem. 2016, 12, 2535–2542, doi:10.3762/bjoc.12.248

• significant potential for photodynamic therapy. Herein we report that squaraines can be immobilized on a self-assembled nanocarrier composed of amphiphilic cyclodextrins to enhance their photochemical activity. To this end, a squaraine was equipped with two adamantane moieties that act as anchors for the

• -assembled from amphiphilic cyclodextrin [27]. Given their negligible toxicity cyclodextrins have been utilized as carriers in a number of studies [28][29]. Amphiphilic cyclodextrins substituted with hydrophobic alkyl groups on the primary side and hydrophilic oligo(ethylene glycol) units on the secondary

• . Amphiphilic β-cyclodextrins substituted with 7 dodecylsulfide groups on the primary side and 7 oligo(ethylene glycol) units on the secondary side were obtained via a straightforward three step synthesis as described [27][30]. A thin film of these amphiphiles was obtained by evaporation of a chloroform

Efficient mechanochemical synthesis of regioselective persubstituted cyclodextrins

• Laszlo Jicsinszky,
• Marina Caporaso,
• Katia Martina,
• Emanuela Calcio Gaudino and
• Giancarlo Cravotto

Beilstein J. Org. Chem. 2016, 12, 2364–2371, doi:10.3762/bjoc.12.230

• -CD derivatives are used in siRNA delivery and gene therapy [6]. The alkyl chain, usually C10–C16, makes the product very amphiphilic, which means that it is difficult to purify not only from possible byproducts but also from the reagents. Additionally, sulfur-containing organic compounds can form

Mutagenic activity of quaternary ammonium salt derivatives of carbohydrates

• Barbara Dmochowska,
• Karol Sikora,
• Anna Woziwodzka,
• Jacek Piosik and
• Beata Podgórska

Beilstein J. Org. Chem. 2016, 12, 1434–1439, doi:10.3762/bjoc.12.138

• or aromatic). Mostly, one of the aliphatic or aromatic residues possesses hydrophobic properties, whereas the nitrogen group is hydrophilic. The QAS molecules have a typical head/tail structure determining their amphiphilic character [5]. QASs find application in many fields of everyday life, and

From N-vinylpyrrolidone anions to modified paraffin-like oligomers via double alkylation with 1,8-dibromooctane: access to covalent networks and oligomeric amines for dye attachment

• Daniela Obels,
• Melanie Lievenbrück and
• Helmut Ritter

Beilstein J. Org. Chem. 2016, 12, 1395–1400, doi:10.3762/bjoc.12.133

• thermo- [18] or/and pH [19] responsive polymers. Besides classical alkylation reactions, Reinecke et al. performed ring-opening reactions to insert functional groups and aromatic side chains [20][21]. Furthermore, they investigated the formation of homogeneous [22] and amphiphilic [23] N-VP networks

Synthesis of a deuterated probe for the confocal Raman microscopy imaging of squalenoyl nanomedicines

• Eric Buchy,
• Branko Vukosavljevic,
• Maike Windbergs,
• Dunja Sobot,
• Camille Dejean,
• Simona Mura,
• Patrick Couvreur and
• Didier Desmaële

Beilstein J. Org. Chem. 2016, 12, 1127–1135, doi:10.3762/bjoc.12.109

• , the use of fluorescent probes requires the covalent binding of large dye molecules (bodipy, cyanine, rhodamine etc, ...) to the drug conjugate, thus potentially modifying its physicochemical profile as well as the in vivo fate and the pharmacological activity. A simple encapsulation of an amphiphilic

Stimuli-responsive HBPS-g-PDMAEMA and its application as nanocarrier in loading hydrophobic molecules

• Yongsheng Chen,
• Li Wang,
• Haojie Yu,
• Zain-Ul-Abdin,
• Ruoli Sun,
• Guanghui Jing,
• Rongbai Tong and
• Zheng Deng

Beilstein J. Org. Chem. 2016, 12, 939–949, doi:10.3762/bjoc.12.92

• aggregates were capable to encapsulate small hydrophobic molecules. These newly prepared HBPS-g-PDMAEMA nanocarriers might be used in, e.g., medicine or catalysis. Keywords: amphiphilic polymer; hyperbranched polystyrene; phase transition; poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA); stimuli

• -responsive nanocarriers; Introduction Stimuli-responsive polymers have attracted much attention due to their broad applications including drug controlled release [1][2][3][4][5], sensing [6][7] and 4D printing [8][9]. Nanocarriers prepared from amphiphilic stimuli-responsive polymers are promising

• blocking hydrophilic PDMAEMA chains on a hydrophobic chain. These amphiphilic polymers may aggregate in water to form nanoparticles having stimuli-responsive properties. Different hydrophobic segments with different microstructures give the aggregates adjustable properties that can be used for various

Aggregation behavior of amphiphilic cyclodextrins in a nonpolar solvent: evidence of large-scale structures by atomistic molecular dynamics simulations and solution studies

• Giuseppina Raffaini,
• Fabio Ganazzoli and
• Antonino Mazzaglia

Beilstein J. Org. Chem. 2016, 12, 73–80, doi:10.3762/bjoc.12.8

• nanoaggregates even in apolar solvents. Keywords: aggregation; amphiphilic cyclodextrins; molecular dynamics; nanoparticles; self-assembly; simulations; Introduction Amphiphilic cyclodextrins (aCD) are a class of molecules highly investigated for their self-assembly properties and inherent potential

• . Furthermore, as the technique is highly sensitive to the aggregates presence, it was not possible to exclude the presence of even nanometric-sized clusters apart from the bigger aggregates [13]. Conclusion Amphiphilic cyclodextrins (aCD) are almost invariably investigated in a water environment for their

• scattering investigations show that, indeed also in a nonpolar solvent such as dichloromethane, these amphiphilic cyclodextrins give rise to quite well defined aggregates, or nanostructures, having a hydrodynamic radius of about 80 nm and a relatively modest polydispersity. This result obtained with a