Search

An injectable polysaccharide supramolecular hydrogel was successfully fabricated from opened D -glucopyranosyl β-cyclodextrin with four aldehyde groups (ACD) cross-linked with biomacromolecule chitosan (CS), which was not only beneficial to the clustering-triggered emission of CS with high quantum yield (32.25%), but also could co-assemble with a first stage acceptor triphenylamine derivative (TPA) and encapsulate Cyanine 5 (Cy5) or Nile blue (NiB) achieving supramolecular cascade energy transfer from the cross-linked polymer to the dyes, leading to fluorescence emission at 673 nm or 680 nm, and could be further applied in cell imaging. [ABSTRACT FROM AUTHOR]

Dynamic systems of cyclodextrins (CDs) enabled by a native cyclodextrin glucanotransferase (CGTase) can incorporate unnatural glucopyranose-derived building blocks, expanding the applicability of enzyme-mediated dynamic combinatorial chemistry by using synthetically modified substrates. Starting dynamic combinatorial libraries from CDs with a single 6-modified glucopyranose results in a dynamic mixture of CDs containing several modified glucopyranoses. The relative concentrations of modified α, β or γ-CDs can be controlled by the addition of templates, providing a novel way to access modified CDs. [ABSTRACT FROM AUTHOR]

Strong interactions between the host cyclodextrin and the threading guest polymer were introduced by selective modifications to the polymer of a polybutadine-based polyrotaxane. The changes in the intercomponent interactions influenced the mobility of the threading polymer that was confined in the glassy host framework, resulting in different mechanical properties. [ABSTRACT FROM AUTHOR]

A series of macrocyclic compounds, including crown ether, cyclodextrin, cucurbituril and pillararene, bound to various specific organic/inorganic/biological guest molecules and ions through various non-covalent interactions, can not only make a single system multifunctional but also endow the system with intelligence, especially for luminescent materials. Due to their excellent luminescence properties, such as long-lived excited states, sharp linear emission bands and large Stokes shift, lanthanides have shown great advantages in luminescence, and have been more and more applied in the design of advanced functional luminescent materials. Based on reported research, we summarize the progress of lanthanide luminescent materials based on different macrocyclic compounds from ion or molecule recognition to functional nano-supramolecular assembly of the lanthanide–macrocycle supramolecular system including photo-reaction mediated switch of lanthanide luminescent molecules, multicolor luminescence, ion detection and cell imaging of rare-earth up-conversion of macrocyclic supramolecular assembly. Finally, we put forward the prospects of future development of lanthanide luminescent macrocyclic supramolecular materials. [ABSTRACT FROM AUTHOR]

Biodegradable supramolecular micelles were prepared exploiting the host–guest interaction of cyclodextrin and adamantane. Cyclodextrin-initiated polypeptides acted as the hydrophilic corona, whereas adamantane-terminated polycaprolactones served as the hydrophobic core. [ABSTRACT FROM AUTHOR]

Inspired by the way templates have been used to drive dynamic combinatorial libraries by molecular recognition, we exploited the photo-responsive host-guest interaction of an azo-based photoswitch with permethylated cyclodextrin to reversibly manipulate the dynamic covalent interaction of a phenyl boronic acid and D -fructose by irradiation with light. [ABSTRACT FROM AUTHOR]

Myoglobin (Mb) is considered as the optimal system for capturing molecular oxygen (O2) in aqueous solution under natural conditions. Therefore, the preparation of artificial systems that mimic the function of Mb is a long-standing and challenging objective. Various sophisticated iron porphyrins have been designed and synthesized to realize O2 biding at their axial positions. Although all of these compounds reversibly bind O2 in absolute organic solvents, no stable O2 adducts were obtained in aqueous solution. The reason for this is the immediate autoxidation of O2 adducts by water molecules. To achieve O2 binding in aqueous solution, the iron center of the porphyrin must be placed in a hydrophobic environment, wherefrom a water molecule is strictly excluded. Another essential requirement for a Mb model is the preparation of an electron-donative axial ligand that plays the role of proximal histidine (His). As an artificial O2 receptor that satisfies these challenging requirements, a supramolecule termed "hemoCD1" has been constructed. HemoCD1, a 1 : 1 inclusion complex of 5,10,15,20-tetrakis(4-sulfonatophenyl)porphinatoiron(II) (FeIITPPS) with a per-O-methylated β-cyclodextrin dimer bearing a pyridine linker (Py3CD), reversibly binds O2 in aqueous solution at neutral pH and ambient temperature. The electronic spectra as well as the functions of hemoCD1 are analogous to those of Mb or its tetramer, hemoglobin (Hb). This is the first example of an artificial Hb/Mb biomimetic model capable of function in aqueous solution. Such a study on hemoCD1 as a Hb/Mb model has expanded research objectives to (1) syntheses of hemoCD1 analogues having distinct characteristics, (2) modeling enzymatic reactions of peroxidase, heme oxygenase, and cytochrome c oxidase in water, (3) development of fully synthetic artificial oxygen carriers (AOCs) utilized in animal blood, and (4) selective binding and removal of toxic small molecules, such as carbon monoxide (CO) and cyanide (CN−) in living organisms. [ABSTRACT FROM AUTHOR]

Although cyclodextrins (CDs) have been used as additives to small molecule surfactants, there are only a few examples of this cyclic oligosaccharide being used as a surfactant template. Herein, we present a novel ionic β-CD derivative that shows significant surface activity and stabilizes oil-in-water emulsions prepared with hexadecane as a model oil. The macrocyclic surfactant strongly reduces the oil–water surface tension with increasing concentration and shows a critical micelle concentration (CMC) around 5 mM. We demonstrate the stability of the oil-in-water emulsions and verify the possibility to address the emulsion droplet surface using molecular recognition of the β-CD cavity at the oil–water interface. [ABSTRACT FROM AUTHOR]

A facile synthetic method is developed to afford cyclodextrin-derived polymer networks that exhibit high selectivity in capturing certain organic compounds in water. The sustainable and scalable synthesis, together with the highly robust adsorption performance enables efficient removal and/or separation of organic molecules from aqueous solution in a continuous flow system. [ABSTRACT FROM AUTHOR]

A supramolecular photosensitizer was constructed using a tetra-adamantane-functionalized porphyrin and a dimer of permethyl-β-cyclodextrin through host–guest interaction and self-assembly. The porphyrin/cyclodextrin alternating structure of supramolecular photosensitizers not only enhances the water solubility of the photosensitizers, but also effectively inhibits the aggregation-induced quenching of porphyrin photosensitizers. [ABSTRACT FROM AUTHOR]

In this study, we have constructed a binary supramolecular nanoassembly composed of α-cyclodextrin-modified hyaluronic acid and an azobenzene-modified diphenylalanine derivative with a positively charged imidazole group. This nanoassembly can bind with siRNA through electrostatic interactions and efficiently delivered them into cancer cells and inhibited their growth. [ABSTRACT FROM AUTHOR]

Surface modification of poly(N-vinyl-2-pyrrolidone)-stabilized gold clusters (1.8 ± 0.6 nm) with aminated cyclodextrins induced aerobic oxidative kinetic resolution of racemic secondary alcohols (krel = 1.2). [ABSTRACT FROM AUTHOR]

A plug and socket approach for tightening polyelectrolyte multilayers is introduced based on the use pendant β-cyclodextrin groups. Prototypical multilayers derived from poly(sodium 4-styrene sulfonate) and β-cyclodextrin-containing poly(4-vinylbenzyltrimethylammonium chloride) are described. Evidence for tightened multilayers has been obtained from gas permeation, swelling and quartz crystal microbalance with dissipation (QCM-D) measurements. [ABSTRACT FROM AUTHOR]

Two porous polymers were synthesized from tetraphenylethylene (TPE) crosslinked β-cyclodextrins (β-CD) and sulfonatocalix[4]arene (SC4A). Owing to the FRET process from the TPE to the encapsulated fluorophores, these polymers provide universal platforms for the fabrication of photo-luminescence tunable organic solid materials. [ABSTRACT FROM AUTHOR]

Discriminating proteins using simple methods is a highly ambitious task. Herein, we provide the first report of a cyclodextrin based supramolecular host–guest assembly, which without involving any specially designed receptor and transducer, yields a distinct fluorescence response i.e., turn-on response towards non-metalloproteins and turn-off response towards metalloproteins, and leads to their detection and discrimination. [ABSTRACT FROM AUTHOR]

A facile method to improve the stability of γ-cyclodextrin metal–organic frameworks (γ-CD-MOFs) in an aqueous environment has been developed through the incorporation of hydrophobic C60 in their matrices, and the resulting hybrid materials were exploited for drug delivery applications. [ABSTRACT FROM AUTHOR]

The synthesis of a water soluble [2]rotaxane is reported using hydrophilic secondary rim functionalised permethylated β-cyclodextrin derivatives as the axle stopper groups. The rotaxane recognises halide anions in pure water with impressive selectivity over sulfate. [ABSTRACT FROM AUTHOR]

Novel 2,3-heterodisubstituted β-cyclodextrin derivatives were designed as artificial enzymes to degrade chemical warfare agents. One of them reduced the acetylcholinesterase inhibitory potential by soman faster than its monosubstituted analog. [ABSTRACT FROM AUTHOR]

Cyclodextrin derivatives are synthesized as membrane-disrupting agents via a microwave-assisted Huisgen reaction. Their ability to permeabilize bacterial membranes depends on the amino substituents and an appropriate balance of hydrophobicity and hydrophilicity, thus enabling the preparation of derivatives with selective toxicity against bacteria. [ABSTRACT FROM AUTHOR]

Formation of a copper(II)-β-cyclodextrin (β-CD) complex in an aqueous medium allowed the regioselective introduction into the oligosaccharide of a benzyl or a bromo-allyl substituent at O-3. [ABSTRACT FROM AUTHOR]