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In present study, monodisperse photoresponsive hollow-shell structured molecularly imprinted polymers (PHSMIPs) were fabricated based on surface imprinting technique and first proposed for selective recognition and adsorption of α-cyclodextrin (α-CD) from complex samples. The structure and the binding properties of PHSMIPs and photoresponsive surface molecularly imprinted polymers (PSMIPs) were compared. Results showed the average diameter of PHSMIPs were about 480 nm with an approximately 40 nm shell. PHSMIPs possessed BET surface areas of 273.4 m 2 /g, the pore volume of 0.333 cm 3 /g, and average pore diameters of 4.3 nm. PHSMIPs displayed higher binding capacity, better recognition ability, and faster mass transfer rate toward α-CD than PSMIPs. Furthermore, PHSMIPs was successfully used in the separation of α-CD in real reaction solution, indicating potential application for purification and selective extraction of α-CD from complex environment., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Biogenic amines (BAs) play significant roles in indicating human health or food quality. Aiming to simultaneously determine three structures (aliphatic, aromatic and heterocyclic) of underivatized BAs, we explored a simple and rapid capillary electrophoresis (CE) method only coupled with conventional UV detector for the separation of thirteen key BAs. The strategy is to choose a UV absorbing probe as co-ion in the background electrolyte (BGE), and different BAs could be characterized by positive or negative peaks according to the fact that their UV absorptivity coefficients at a certain wavelength are better or worse than that of the UV absorbing probe. After the detailed investigation of critical parameters as pH, the concentration of Imidazole (Im) and α-cyclodextrin (α-CD), the optimized BGE consisted of 12.0mmol/L Im as the UV probe and 10.0mmol/L α-CD as the additive (at pH 4.50 adjusted with acetic acid). With such condition, the targets of thirteen BAs were baseline separated in 9.0min and appeared at nine positive peaks and four negative peaks at 200nm. The obtained LODs and LOQs (S/N=3 or 10) were in the range of 0.36-3.67 and 1.2-12.2μmol/L, respectively. The interday RSDs of migration time and peak area were less than 0.7% and 4.7% (n=6), respectively. To the best of our knowledge, this is the first report on separating diverse structures of BAs by using Im as UV absorbing probe. The thirteen BAs were simultaneously detected by direct and indirect UV detection in a CE process. To verify the applicability, this method was used to analyze BAs in commercial beer samples. The recoveries of all BAs except carnosine (not identified by the interference) ranged from 70.4 to 119.6%, and four aliphatic and aromatic amines were satisfactorily identified and quantified., (Copyright © 2016 Elsevier B.V. All rights reserved.)

To expand the applications of glow discharge microplasma into biological analysis, an innovative ambient ion source for mass spectrometry, microplasma probe desorption/ionization mass spectrometry (MPPDI-MS), has been developed and demonstrated. Electrodes and a sampling tube were creatively combined using a stainless steel syringe needle, and efficient methods of introduction for biological samples in solid, liquid, and gaseous phases like phospholipid and amino acids were specially designed. Based on the active species generated by glow discharge plasma, simplified protonated spectra were obtained without extra solvent spray assistance. The method is easy to operate and versatile and especially has the ability to distinguish the isomeric compounds of ketone and aldehyde. Quantitative results of this method for different biological samples in different phases were also performed well. It was proved that with further improvement, this sensitive and selective analysis using MPPDI-MS with minimal invasiveness will be an ingenious tool in disease diagnosis and single-cell detections in the future.

This article describes a straightforward gas-liquid microfluidic approach to generate uniform-sized chitosan microcapsules containing CdS quantum dots (QDs). CdS QDs are encapsulated into the liquid-core of the microcapsules. The sizes of the microcapsules can be conveniently controlled by gas flow rate. QDs-chitosan microcapsules show good fluorescent stability in water, and exhibit fluorescent responses to chemical environmental stimuli. α-Cyclodextrin (α-CD) causes the microcapsules to deform and even collapse. More interestingly, α-CD induces obvious changes on the fluorescent color of the microcapsules. However, β-cyclodextrin (β-CD) has little influence on the shape and fluorescent color of the microcapsules. Based on the results of scanning electron microscopy, the possible mechanism about the effects of α-CD on the chitosan microcapsules is analyzed. These stimuli-responsive microcapsules are low-cost and easy to be prepared by gas-liquid microfluidic technique, and can be applied as a potential micro-detector to chemicals, such as CDs., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Unlabelled: Although α-, β-, and γ-cyclodextrins (CDs) have been widely used to improve the color of different fruit juices, a comparative study of the effect of these natural CDs on other properties that also influence pear juice quality, such as odor and aroma, have not been reported yet. In this study, the comparative effect of the addition of α-, β-, and γ-cyclodextrin, the only CDs authorized to be used in the food industry by U.S. Food and Drug Administration (FDA) and European Union, on the pear juice quality was evaluated for the first time. Several instrumental and sensory properties of this fruit juice, such as color, volatile composition, odor, and aroma have been evaluated in the absence and presence of α-, β-, and γ-CD. A study of the aroma profile of pear juice showed that esters, aldehydes, alcohols, and terpenes were the most important chemical families. However, the addition of α-, β-, and γ-CD had different effects on both the concentration of individual volatile compounds and their chemical grouping. Furthermore, a trained sensory panel was used to evaluate color, overall odor, overall aroma, and overall quality of pear juice in the presence or absence of CDs., Practical Application: After comparing the effects of the addition of α-, β-, and γ-CD on pear juice, our final recommendation is to add α-CD (the natural CD formed by 6 units of glucose) to pear juice because it will significantly increase the global quality of the juice by reducing its browning but without producing a significant reduction in the aroma quality., (© 2011 Institute of Food Technologists®)

The inclusion complex formation of aspartame (guest) and various cyclodextrins (host) were examined using 1H NMR titration and capillary electrophoresis. Initially the protonation constants of aspartame were determined by NMR-pH titration with in situ pH measurement to yield log K1=7.83 and log K2=2.96. Based on these values the stability of the complexes formed by aspartame and 21 different cyclodextrins (CDs) were studied at pH 2.5, pH 5.2 and pH 9.0 values where aspartame exists predominantly in monocationic, zwitterionic and monoanionic form, respectively. The host cyclodextrin derivatives differed in various sidechains, degree of substitution, charge and purity so that the effect of these properties could be examined systematically. Concerning size, the seven-membered beta-cyclodextrin and its derivatives have been found to be the most suitable host molecules for complexation. Highest stability was observed for the acetylated derivative with a degree of substitution of 7. The purity of the CD enhanced the complexation while the degree of substitution did not provide obvious consequences. Finally, geometric aspects of the inclusion complex were assessed by 2D ROESY NMR and molecular modelling which proved that the guest's aromatic ring enters the wider end of the host cavity.

Water-soluble supramolecular inclusion complexes of alpha-, beta-, and gamma-cyclodextrin-bicapped C60 (CD/C60) have been investigated for their photoinduced DNA cleavage activities, with the aim to assess the potential health risks of this class of compounds and to understand the effect of host cyclodextrins having different cavity dimensions. Factors such as incubation temperature, irradiation time, and concentration of NADH or CDs/ C60 supramolecular inclusion complexes have been examined. The results show that alpha-, beta-, and gamma-CDs/C60 are all able to cleave double-stranded DNA under visible light irradiation in the presence of NADH. However, a difference in the photoinduced DNA cleavage efficiency is observed, where the cleavage efficiency increases in the order of alpha-, beta-, and gamma-CD/C60. The difference is attributed to the different aggregation behavior of the inclusion complexes in aqueous solution, which is correlated to the cavity dimension of the host cyclodextrin molecules.

9-Aminoacridine was established as a matrix for the detection of neutral oligosaccharides in negative ion mode matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry. Sodium iodide proved to be a useful additive inducing formation of stable iodide adducts of the analytes, in particular for oligosaccharides with a degree of polymerisation (DP) of three and higher. Lower oligomers (DP <3) and monosaccharides show more stable adducts with chloride ions. After optimisation of the sample preparation procedure, limits of quantitation were determined for alpha-cyclodextrin and cellopentaose at 7 and 13 pmol, respectively, with a linear detector response over two concentration orders. The iodide additive could be successfully employed on MALDI-TOF mass spectrometers with vacuum and atmospheric pressure ion sources. The value of the new method to solve biological problems has been demonstrated by the analysis of a mixture of beta-glucane elicitors isolated from the cell walls of Phytophthora sojae.

Ferulic acid (FA) is a highly effective antioxidant and photo-protective agent, already approved in Japan as a sunscreen, but it is poorly suited for cosmetic application because of its low physicochemical stability. We prepared the inclusion complex of FA with alpha-cyclodextrin by co-precipitation from an aqueous solution, and used (1)H NMR and molecular dynamics to investigate the most probable structure of the inclusion complex. In rotating frame nuclear Overhouser effect spectroscopy (ROESY) experiments FA penetrated the alpha-CD hydrophobic cavity with the alpha,beta-unsaturated part of the molecule and some of its aromatic skeleton. In proton chemical shift measurements of FA and alpha-cyclodextrins we determined the stoichiometry of the association complex (1:1) by Job's method, and its stability constant (K(1:1) 1162+/-140 M(-1)) and described the molecular dynamics of the complex on the basis of theoretical studies. Encapsulation with alpha-cyclodextrin improves (i) the chemical stability of FA against UVB stress (10 MED [Minimal Erythemal Dose: 1 MED=25 mJ/cm(2) for skin phototype II: 30]), since no degradation products are formed after irradiation, and (ii) the bioavailability of FA on the skin, slowing its delivery (Strainer cell model).

This paper describes a new infrared (IR) sensing method for rapidly determining the enantiomeric compositions of chiral compounds through the use of a chirality-selective compound immobilized on the surface of the evanescent-wave sensing elements. alpha-Cyclodextrin (alpha-CD) was selected as this agent and it was immobilized on a zinc selenide sensing element to allow different analytical signals to be generated for each compound of a pair of enantiomers. Theoretical working equations were developed to monitor the response of the ATR-IR spectroscopic sensor during this process. The difference between the formation constants of enantiomers was crucial to the sensitivity when determining the enantiomeric compositions. Control of the pH of the solution could be used to effectively increase the difference between these formation constants. Based on the static sensing system with optimal conditions, the ratio of the values of the signals of the two enantiomers was <0.4. A linear relationship between the analytical signals and the mole fraction of the enantiomers was obtained under conditions in which the concentration of the chiral compound was sufficiently low. Based on the detected time profiles, this sensing method had a fast response: the detection time could be <10min. With a flow-cell configuration, the time to finish one determination can be shorter than 10min with similar sensitivity and accuracy as in static sensing system.

Cyclodextrins, especially random methylated betaCD (RAMEB) and hydroxypropyl betaCD (HPbetaCD), are becoming common enhancing additives in the bioremediation of soils formerly contaminated by hydrocarbons and/or other poorly bioavailable organic pollutants. Therefore, their degradation in the soil, particularly the most persistent RAMEB, has been of great concern. Like oil contaminants, these additives should be biodegradable via an environmentally safe technology. Hence, in this paper, the biodegradability of eight different cyclodextrins (CDs) in four different soils was examined under various treatment conditions in laboratory and pilot scale field experiments. This paper is the first report on the potential biological fate of CDs studied under a large variety of environmental conditions and in different soil ecosystems. Data on the potential relationship between CD biodegradation and the biological removal of hydrocarbons in the CD-amended contaminated soils are also given. All CDs were found to be more or less biodegradable; even the most persistent RAMEB was depleted from soils under favourable conditions. In the field experiments, the depletion of RAMEB to about 40% of its initial level was observed for a period of 2 years in hydrocarbon-contaminated soils of high organic matter and cell concentration.

The interaction of norflurazon with alpha- and gamma-cyclodextrins (CDs) yielded the formation of inclusion complexes at a 1:1 stoichiometric ratio in solution and in the solid state. Apparent stability constants of 50.7+/-1.6 and 37+/-1.7 M(-1) and an increase in herbicide solubility by up to five and fourfold for alpha- and gamma-CD, respectively, were determined from the phase solubility diagrams at 25 degrees C in water. Three processing methods (kneading, spray-drying and vacuum evaporation) were used to prepare norflurazon-CD solid inclusion complexes, which were characterised by infrared spectroscopy, differential scanning calorimetry and scanning electron microscopy. A high increase in the norflurazon dissolution rate was obtained with all the solid complexes with gamma-CD, but when alpha-CD was used, only the solid system obtained after the vacuum evaporation process showed a higher dissolution rate. This finding is a first step in the development of new, environmentally sound formulations of norflurazon (NFL), due to the capacity for increasing its dissolution rate and hydrosolubility, and thus diminishing the use of organic solvents. On the other hand, the effect of alpha- and gamma-cyclodextrin on the solubility of norflurazon in solution was also considered as a way of modifying its behaviour in the soil environment. Desorption studies of NFL from soils in the presence of alpha- and gamma-cyclodextrin were carried out using a batch equilibration method. The results obtained showed that alpha- and gamma-cyclodextrin greatly increased the removal of norflurazon previously adsorbed, proving the potential use of these CDs for in situ remediation of pesticide-contaminated soils.

Inclusion complexes (ICs) between alpha-cyclodextrin (alpha-CD) and three kinds of biodegradable aliphatic polyesters with different sequence lengths of the monomeric repeating units poly(3-hydroxypropionate) [P(3HP)], poly(4-hydroxybutyrate) [P(4HB)] and poly(epsilon-caprolactone)(PCL) were prepared by mixing a solution of alpha-CD with that of the polymer, followed by stirring. The ICs were obtained as insoluble precipitates and characterized by FT-IR, WAXD and DSC. All measurements showed that the polymer chains of all three kinds of polyester were included into the alpha-CD cavity and formed ICs with different stoichiometries. WAXD patterns and thermal analysis indicated that these ICs possessed a channel structure and the crystallization of the polyester chains was suppressed upon inclusion into the alpha-CD cavity.

The third, concluding member of the family of single-isomer, fully sulfated alpha-cyclodextrins, the sodium salt of hexakis(2,3-di-O-methyl-6-O-sulfo)-alpha-cyclodextrin (HxDMS), has been synthesized on the kilogram scale, completing the nine-member array of the single-isomer, 6-O-sulfo CDs now available. HxDMS was tested for the capillary electrophoretic (CE) resolution of the enantiomers of nonelectrolyte, weak acid and weak base analytes contained in our CD screening kit. HxDMS complexed differently with many of the analytes tested than either its larger-ring analogs, heptakis(2,3-di-O-methyl-6-O-sulfo)-beta-CD (HDMS) and octakis(2,3-di-O-methyl-6-O-sulfo)-gamma-CD (ODMS) or its same-ring, but differently substituted analogs, hexakis(6-O-sulfo)-alpha-CD (HxS) and hexakis(2,3-di-O-acetyl-6-O-sulfo)-alpha-CD (HxDAS). For all analytes, the effective mobilities and separation selectivities as a function of the background electrolyte concentration of HxDMS followed the trends that were found for the other single-isomer, 6-O-sulfo CDs.

Inclusion complexes of some flavonols (3-hydroxyflavone, morin and quercetin) have been obtained with alpha- and beta-cyclodextrins, by the co-evaporation method. Different analytical techniques (DSC, XRPD, FT-IR, 1H-NMR, UV-Vis) have been employed for a throughout investigation of the structural characteristics of such supramolecular aggregates, which exhibited distinct spectroscopic features and properties from both "guest" and "host" molecules. The stoichiometric ratios and stability constants describing the extent of formation of the complexes have been determined by phase-solubility studies; in all cases type-AL diagrams have been obtained (soluble 1:1 complexes). The effect of molecular encapsulation on the flavonols antioxidant activity has been afterwards evaluated, by means of different biological assays (Bathophenanthroline test; Comet assay; Lipid peroxidation). Complexation with cyclodextrins further improved the antioxidant activity, increasing drugs solubility in the biological moiety.