Dynamics and interactions of ibuprofen in cyclodextrin nanosponges by solid-state NMR spectroscopy

• Monica Ferro,
• Franca Castiglione,
• Nadia Pastori,
• Carlo Punta,
• Lucio Melone,
• Walter Panzeri,
• Barbara Rossi,
• Francesco Trotta and
• Andrea Mele

Beilstein J. Org. Chem. 2017, 13, 182–194, doi:10.3762/bjoc.13.21

• condensation reaction of the OH groups of the glucopyranose units of cyclodextrins (CD) with a poly-functional cross-linking agent [3]. CDNS have been characterized, in the solid state, by a repertoire of physical methods such as solid-state 13C CP-MAS NMR, FTIR and Raman spectroscopy [4][5][6]. Moreover, in

• result is that the guest molecules are mainly confined in the pores formed by the polycondensation process rather than forming a genuine inclusion complex with the single CD units. From a practical point of view, our class of polymerized cyclodextrins can be conveniently exploited as sorbent or scaffold

Phosphated cyclodextrins as water-soluble chiral NMR solvating agents for cationic compounds

• Cira Mollings Puentes and
• Thomas J. Wenzel

Beilstein J. Org. Chem. 2017, 13, 43–53, doi:10.3762/bjoc.13.6

• Cira Mollings Puentes Thomas J. Wenzel Department of Chemistry, Bates College, Lewiston, Maine 04240 USA 10.3762/bjoc.13.6 Abstract The utility of phosphated α-, β- and γ-cyclodextrins as water-soluble chiral NMR solvating agents for cationic substrates is described. Two sets of phosphated

• cyclodextrins, one with degrees of substitution in the 2–6 range, the other with degrees of substitution in the 6–10 range, are examined. Results with 33 water-soluble cationic substrates are reported. We also explored the possibility that the addition of paramagnetic lanthanide ions such as praseodymium(III

• ) and ytterbium(III) further enhances the enantiomeric differentiation in the NMR spectra. The chiral differentiation with the phosphated cyclodextrins is compared to prior results obtained with anionic carboxymethylated cyclodextrins. There are a number of examples where a larger differentiation is

Synthesis of multi-lactose-appended β-cyclodextrin and its cholesterol-lowering effects in Niemann–Pick type C disease-like HepG2 cells

• Keiichi Motoyama,
• Rena Nishiyama,
• Yuki Maeda,
• Taishi Higashi,
• Yoichi Ishitsuka,
• Yuki Kondo,
• Tetsumi Irie,
• Takumi Era and
• Hidetoshi Arima

Beilstein J. Org. Chem. 2017, 13, 10–18, doi:10.3762/bjoc.13.2

• children, results in severe hepatosplenomegaly and neurodegeneration [3][6]. Hence, the sequestration of cholesterol is an important factor in the development of the NPC disease. Cyclodextrins (CDs) are cyclic glucose oligosaccharides used by the pharmaceutical industry to enhance solubility, stability

Versatile synthesis of end-reactive polyrotaxanes applicable to fabrication of supramolecular biomaterials

• Atsushi Tamura,
• Asato Tonegawa,
• Yoshinori Arisaka and
• Nobuhiko Yui

Beilstein J. Org. Chem. 2016, 12, 2883–2892, doi:10.3762/bjoc.12.287

• functional PRXs and can be applied to the fabrication of PRX-based supramolecular biomaterials. Keywords: azide group; biomaterials; click chemistry; cyclodextrin; polyrotaxane; Introduction Polyrotaxanes (PRXs) are a class of interlocked polymers that consist of an inclusion complex of cyclodextrins (CDs

Stabilization of nanosized titanium dioxide by cyclodextrin polymers and its photocatalytic effect on the degradation of wastewater pollutants

• Tamás Zoltán Agócs,
• István Puskás,
• Erzsébet Varga,
• Mónika Molnár and
• Éva Fenyvesi

Beilstein J. Org. Chem. 2016, 12, 2873–2882, doi:10.3762/bjoc.12.286

• nanosized titanium dioxide (nanoTiO2) applied in photodegradation-based procedures can be stabilized with cyclodextrins in order to obtain a new, more efficient photocatalyst for the purification of waters polluted by xenobiotics applying UV irradiation. During our work, on the one hand, we studied the

• 90% and rutile 10% with a specific surface area of 90–100 m2/g and mean particle size 14 nm). This dispersion (pH was about 2) was diluted to 0.02% for the experiments. The cyclodextrins characterized by the degree of substitution (DS) in the case of monomers and by the CD content in the case of

• (1%), nanoTiO2 (0.02%) and nanoTiO2 (0.02%) stabilized by CMBCD-P (1%). Half life time (min) of photodecomposition of IBR in distilled and tap water. Cyclodextrins used during the experiments. Acknowledgements The authors thank to Katalin Csabai for the size exclusion chromatography of the polymer.

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

• Loic Leclercq Univ. Lille, CNRS, ENSCL, UMR 8181 – UCCS - Equipe CÏSCO, F-59000 Lille, France 10.3762/bjoc.12.261 Abstract In the field of host–guest chemistry, some of the most widely used hosts are probably cyclodextrins (CDs). As CDs are able to increase the water solubility of numerous drugs

• reviewed as well as their interactions with isolated biomolecules leading to the formation of inclusion or exclusion complexes. Finally, some potential medical applications are highlighted throughout several examples. Keywords: cellular interactions; cyclodextrins; endogenous substances; extraction

• ; greener active ingredients; host–guest chemistry; lipids; Introduction Cyclodextrins (CDs) were discovered and identified over a century ago [1][2][3]. Between 1911 and 1935, Pringsheim and co-workers demonstrated the ability of CDs to form complexes with many organic molecules [4][5]. Since the 1970s

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

Radical polymerization by a supramolecular catalyst: cyclodextrin with a RAFT reagent

• Kohei Koyanagi,
• Yoshinori Takashima,
• Takashi Nakamura,
• Hiroyasu Yamaguchi and
• Akira Harada

Beilstein J. Org. Chem. 2016, 12, 2495–2502, doi:10.3762/bjoc.12.244

• polymerase, and λ-exonuclease demonstrate that the cylindrical cavities of enzymes can effectively recognize substrates to produce biological polymers [1][2][3][4][5][6]. Cyclodextrins (CDs) have been widely used as substrate-recognition moieties in artificial enzymes [7][8][9][10][11][12][13][14][15], which

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

• millimolar scale, they are easily scalable. Keywords: green chemistry; nucleophilic substitution; planetary ball mill; siRNA delivery intermediate; sugammadex; Introduction Cyclodextrins (CDs) are cyclic α(1→4)glucopyranosides and have been fully described in a number of publications [1][2][3]. They are

Cross-linked cyclodextrin-based material for treatment of metals and organic substances present in industrial discharge waters

• Élise Euvrard,
• Nadia Morin-Crini,
• Coline Druart,
• Justine Bugnet,
• Bernard Martel,
• Cesare Cosentino,
• Virginie Moutarlier and
• Grégorio Crini

Beilstein J. Org. Chem. 2016, 12, 1826–1838, doi:10.3762/bjoc.12.172

• cross-linked cyclodextrin-based polymer for the removal of metals and organic pollutants present in polycontaminated effluents. Cyclodextrins (CDs), synthetic substances obtained from the enzymatic degradation of starch, belong to the family of cage molecules. They present remarkable encapsulation

Superstructures with cyclodextrins: chemistry and applications III

• Gerhard Wenz and
• Eric Monflier

Beilstein J. Org. Chem. 2016, 12, 937–938, doi:10.3762/bjoc.12.91

• Gerhard Wenz Eric Monflier Saarland University, Organic Macromolecular Chemistry, Campus C4 2, 66123 Saarbrücken, Germany Université d’Artois, Unité de Catalyse et de Chimie du Solide (UCCS), CNRS, UMR 8181, Rue Jean Souvraz, SP 18, 62307 Lens, France 10.3762/bjoc.12.91 Keywords: cyclodextrins

• ; Cyclodextrins (CDs) are of increasing scientific and commercial interest because they are readily available, harmless and well-defined, forming sophisticated supramolecular structures in aqueous media. More than 2,300 publications and more than 1,200 patents appeared in 2015 in which CDs played a significant

• Symposium with 200 participants, 34 oral presentations and over 100 poster contributions took place in Kumamoto, Japan on May 14–16, 2015. The 4th European Conference on Cyclodextrins was held in Lille, France on October 6–9, 2015 and brought together 170 researchers from 29 countries across the world. This

Interactions between 4-thiothymidine and water-soluble cyclodextrins: Evidence for supramolecular structures in aqueous solutions

• Vito Rizzi,
• Sergio Matera,
• Paola Semeraro,
• Paola Fini and
• Pinalysa Cosma

Beilstein J. Org. Chem. 2016, 12, 549–563, doi:10.3762/bjoc.12.54

• Since several years the inclusion of organic compounds (guests) within the hydrophobic cavity (host) of cyclodextrins (CDs) has been the subject of many investigations. Interestingly, the formation of inclusion complexes could affect the properties of the guest molecules and, for example, the influence

• appears to be 1:1 for all examined CDs. Keywords: cyclodextrins; inclusion complex; photodynamic therapy; Introduction Since several years, supramolecular chemistry has been considered the chemistry of the intermolecular bonds inducing the association of several chemical species with the formation of

• mentioning that among different kinds of non-covalent interactions, the host–guest type is extensively discussed in literature covering a large field of applications [4]. For example, cyclodextrins (CDs), among host molecules, are reported to occupy an important place in the field of inclusion phenomena [5

New synthetic strategies for xanthene-dye-appended cyclodextrins

• Milo Malanga,
• Andras Darcsi,
• Mihaly Balint,
• Gabor Benkovics,
• Tamas Sohajda and
• Szabolcs Beni

Beilstein J. Org. Chem. 2016, 12, 537–548, doi:10.3762/bjoc.12.53

• University, Hlavova 8, 12843 Prague 2, Czech Republic 10.3762/bjoc.12.53 Abstract Xanthene dyes can be appended to cyclodextrins via an ester or amide bridge in order to switch the fluorescence on or off. This is made possible through the formation of nonfluorescent lactones or lactams as the fluorophore

• can reversibly cyclize. In this context we report a green approach for the synthesis of switchable xanthene-dye-appended cyclodextrins based on the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMT-MM). By using 6-monoamino-β-cyclodextrin and commercially available

• inexpensive dyes, we prepared rhodamine- and fluorescein-appended cyclodextrins. The compounds were characterized by NMR and IR spectroscopy and MS spectrometry, their UV–vis spectra were recorded at various pH, and their purity was determined by capillary electrophoresis. Two potential models for the

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

• fluorophores bound in the cavity of cyclodextrins to measure Keq values, our idea was to instead exploit the displacement as the sensing modality. Thus, the idea of an indicator-displacement assay (IDA) was born [58][59]. As with so many “new” ideas in chemistry, the approach had actually been used before, by

Optimized methods for preparation of 6^I-(ω-sulfanyl-alkylene-sulfanyl)-β-cyclodextrin derivatives

• Eva Bednářová,
• Simona Hybelbauerová and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2016, 12, 349–352, doi:10.3762/bjoc.12.38

• disulfides are derivatives usable for well-defined covalent attachment of cyclodextrin to gold or polydopamine-coated solid surfaces. Keywords: cyclodextrins; disulfides; monosubstituted derivatives; thiols; Introduction Cyclodextrins (CDs) [1], cyclic oligomers of α-D-glucopyranose, are used for their

• -cyclodextrins (β-CD-S-X-SH) – which can be attached to a gold surface [9][10] or a polydopamine-coated surface [11]. It has been already described that the surface coverage of self-assembled monolayers of CD derivatives on gold depends substantially on the linker between the sulfanyl group and the CD

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

• green strategies for the selective modification of cyclodextrins (CDs) is still a challenging task. Outstanding results have been achieved in recent years by means of so-called enabling technologies, such as microwaves, ultrasound and ball mills, that have become irreplaceable tools in the synthesis of

Interactions of cyclodextrins and their derivatives with toxic organophosphorus compounds

• Sophie Letort,
• Sébastien Balieu,
• William Erb,
• Géraldine Gouhier and
• François Estour

Beilstein J. Org. Chem. 2016, 12, 204–228, doi:10.3762/bjoc.12.23

• on the current use of cyclodextrins against organophosphorus compound intoxications. Organophosphorus pesticides and nerve agents play a determinant role in the inhibition of cholinesterases. The cyclic structure of cyclodextrins and their toroidal shape are perfectly suitable to design new chemical

• detect and to degrade organophosphate nerve agents [27]. In this respect, cyclodextrins (CDs) are interesting scaffolds because of their macrocyclic structure able to bind more or less selectively some organic substrates via non covalent interactions [28][29][30]. Due to their affinity for

• effect of CDs, probably due to a higher steric hindrance around the torus. Later, the effect of native cyclodextrins on the photodegradation of organophosphorus pesticides was evaluated in water containing humic acids [61]. In these conditions, the three native CDs promote the photodegradation of the

Thermal and oxidative stability of Atlantic salmon oil (Salmo salar L.) and complexation with β-cyclodextrin

• Daniel I. Hădărugă,
• Mustafa Ünlüsayin,
• Alexandra T. Gruia,
• Cristina Birău (Mitroi),
• Gerlinde Rusu and
• Nicoleta G. Hădărugă

Beilstein J. Org. Chem. 2016, 12, 179–191, doi:10.3762/bjoc.12.20

• -containing microcapsules [27][33] and spontaneous emulsification for obtaining nanoemulsions [20][31][32]. One nanoencapsulation method of fish oil components is the molecular encapsulation in cyclodextrins (CDs). The latter are natural or synthetically modified, cyclic oligosaccharides comprising 6, 7, and

Supramolecular structures based on regioisomers of cinnamyl-α-cyclodextrins – new media for capillary separation techniques

• Gabor Benkovics,
• Ondrej Hodek,
• Martina Havlikova,
• Zuzana Bosakova,
• Pavel Coufal,
• Milo Malanga,
• Eva Fenyvesi,
• Andras Darcsi,
• Szabolcs Beni and
• Jindrich Jindrich

Beilstein J. Org. Chem. 2016, 12, 97–109, doi:10.3762/bjoc.12.11

• This work focuses on the preparation and application of supramolecular structures based on mono-cinnamyl-α-cyclodextrins (Cin-α-CD). Pure regioisomers of Cin-α-CD having the cinnamyl moiety at the 2-O- or at the 3-O-position, respectively, were prepared, characterized and applied in capillary

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

• , Farmaceutiche ed Ambientali dell’Università di Messina, V. le F. Stagno d'Alcontres 31, 98166 Messina, Italy 10.3762/bjoc.12.8 Abstract Chemically modified cyclodextrins carrying both hydrophobic and hydrophilic substituents may form supramolecular aggregates or nanostructures of great interest. These systems

• with a hydrodynamic radius of the order of 80 nm and a relatively modest polydispersity, even though smaller nanometer-sized aggregates cannot be fully ruled out. Taken together, these simulation and experimental results indicate that amphiphilically modified cyclodextrins do also form large-scale

• 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

Supramolecular polymer assembly in aqueous solution arising from cyclodextrin host–guest complexation

• Jie Wang,
• Zhiqiang Qiu,
• Yiming Wang,
• Li Li,
• Xuhong Guo,
• Duc-Truc Pham,
• Stephen F. Lincoln and
• Robert K. Prud’homme

Beilstein J. Org. Chem. 2016, 12, 50–72, doi:10.3762/bjoc.12.7

• ], chemical sensors [6] and drug delivery [7][8][9]. As discussed in a range of reviews [10][11][12][13][14] and books [15][16][17][18], cyclodextrins are naturally occurring cyclic oligosaccharides which are also produced industrially through the enzymatic metabolism of starch and related compounds. The

• enzymes used are cyclodextrin glucosyltransferases which are produced by several microorganisms including Bacillus macerans and Bacillus circulans. The most common cyclodextrins are α-, β- and γ-cyclodextrin (α-, β- and γ-CD) which consist of 6, 7 and 8 α-1,4-linked D-glucopyranose subunits, respectively

• . Stabilized by intramolecular hydrogen bonds, cyclodextrins form truncated toroidal structures with different internal annular diameters but the same depth of 7.9 Å (Figure 1, Table 1) [19]. The primary hydroxy groups are located on the C6 carbons of the D-glucopyranose subunits and delineate the narrower, or

Determination of formation constants and structural characterization of cyclodextrin inclusion complexes with two phenolic isomers: carvacrol and thymol

• Miriana Kfoury,
• David Landy,
• Steven Ruellan,
• Lizette Auezova,
• Hélène Greige-Gerges and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2016, 12, 29–42, doi:10.3762/bjoc.12.5

• . However, they suffer from poor aqueous solubility and pronounced flavoring ability that limit their application in food systems. These drawbacks could be surpassed by encapsulation in cyclodextrins (CDs). Applications of their inclusion complexes with CDs were reported without investigating the inclusion

• : cyclodextrins; DOSY-NMR; formation constant; molecular modeling; solubility; Introduction Carvacrol (2-methyl-5-(1-methylethyl)phenol, 1) and thymol (5-methyl-2-(1-methylethyl)phenol, 2) are monoterpenic phenol isomers (Figure 1) produced by several aromatic plants (oregano, thyme, savory, marjoram, etc.) [1

• for loss during storage or heat treatement [16] and their relatively high flavor impact and low flavor threshold that lead to the deterioration of food organoleptic quality [4]. Encapsulation in cyclodextrins (CDs) could overcome these limitations. Indeed, CDs have the ability to increase the

Polydisperse methyl β-cyclodextrin–epichlorohydrin polymers: variable contact time ¹³C CP-MAS solid-state NMR characterization

• Isabelle Mallard,
• Davy Baudelet,
• Franca Castiglione,
• Monica Ferro,
• Walter Panzeri,
• Enzio Ragg and
• Andrea Mele

Beilstein J. Org. Chem. 2015, 11, 2785–2794, doi:10.3762/bjoc.11.299

• remove organic pollutants [6][11][12][13] and heavy metals [14] from water. The most efficient method for the synthesis of insoluble polymers is to use di- or polyfunctional linkers with monomers of cyclodextrins. Different effective crosslinkers have been reported in the literature such as

• epichlorohydrin [15][16], isocyanates [17][18], polycarboxylic acids [19][20] and anhydrides [21]. Following a slightly different approach, Trotta [18] and his group demonstrated that polymerization of cyclodextrins with a variety of synthetic equivalents of di- and tetracarboxylic acids provides an easy

Physical properties and biological activities of hesperetin and naringenin in complex with methylated β-cyclodextrin

• Waratchada Sangpheak,
• Jintawee Kicuntod,
• Roswitha Schuster,
• Thanyada Rungrotmongkol,
• Peter Wolschann,
• Nawee Kungwan,
• Helmut Viernstein,
• Monika Mueller and
• Piamsook Pongsawasdi

Beilstein J. Org. Chem. 2015, 11, 2763–2773, doi:10.3762/bjoc.11.297

• hesperetin with cyclodextrins (β-CD and DM-β-CD) were theoretically investigated by molecular dynamics simulation. The free energy values obtained suggested a more stable inclusion complex with DM-β-CD. The vdW force is the main guest–host interaction when hesperetin binds with CDs. The phase solubility

• three different cancer cell lines. The overall results suggested that solubilities and bioactivities of both flavanones were increased by complexation with methylated β-CDs. Keywords: binding energy; bioactivity; cyclodextrins; hesperetin; naringenin; Introduction Flavonoids are secondary metabolites

• physical properties and biological activities of hesperetin and naringenin through complexation with cyclodextrins. Computational tools (molecular dynamics simulation) were adopted to first predict the stability of flavanones/CDs inclusion complexes. Consequently, the experimental phase solubility and

Synthesis and photophysical characteristics of polyfluorene polyrotaxanes

• Aurica Farcas,
• Giulia Tregnago,
• Ana-Maria Resmerita,
• Pierre-Henri Aubert and
• Franco Cacialli

Beilstein J. Org. Chem. 2015, 11, 2677–2688, doi:10.3762/bjoc.11.288

• polyrotaxane compounds exhibit a granular morphology with lower dispersity and smaller roughness exponent of the film surfaces in comparison with those of the neat copolymer 3. Keywords: energy band gaps; fluorescence lifetimes; permethylated cyclodextrins; polyfluorene; polyrotaxanes; Introduction Over the

• wide variety of host molecules have the ability to encapsulate the π-conjugated backbones into their cavities based on intermolecular interactions, and thus leading to ICs. Cyclodextrins (CDs) are by far the most intensively investigated macrocyclic molecules in the synthesis of such supramolecular