Search results for "cyclodextrins"

Fast enantiomeric separation of uniconazole and diniconazole by electrokinetic chromatography using an anionic cyclodextrin: application to the deter…

2000

The enantiomeric resolution of the fungicides uniconazole and diniconazole was performed using electrokinetic chromatography with cyclodextrins as pseudostationary phase (CD-EKC). A systematic evaluation of several chiral selectors was made. The anionic derivative carboxymethylated-gamma-cyclodextrin (CM-gamma-CD) was found to be the most appropriate for the enantioseparation of fungicides among all cyclodextrins tested. The influence of some experimental conditions such as nature and buffer pH, chiral selector concentration, and temperature on the enantiomeric separation of the compounds studied was also investigated. The use of a 50 mM phosphate buffer (pH 6.5) containing 5 mM CM-gamma-CD…

Probes for studying cholesterol binding and cell biology.

2011

Cholesterol is a multifunctional lipid in eukaryotic cells. It regulates the physical state of the phospholipid bilayer, is crucially involved in the formation of membrane microdomains, affects the activity of many membrane proteins, and is the precursor for steroid hormones and bile acids. Thus, cholesterol plays a profound role in the physiology and pathophysiology of eukaryotic cells. The cholesterol molecule has achieved evolutionary perfection to fulfill its different functions in membrane organization. Here, we review basic approaches to explore the interaction of cholesterol with proteins, with a particular focus on the high diversity of fluorescent and photoreactive cholesterol prob…

Catalytic properties of Ag-PolyaminoβCD NPs for reduction of nitroarenes

2014

The reduction of nitroarenes is a key reaction involved in the synthesis of several compounds such as drugs, pesticides or dyes. During the last years Pd and Ag NPs have been used as catalysts to carry out this reaction with NaBH4. However several mechanistic aspects of the process are still unclear; in particular there is not agreement about the kinetic order of these reactions, whether 0-th or 1-st order in the substrate[1]. The aim of this work is to use a novel catalytic systems constituted by Ag-NPs coated with different polyamino-βCDs (Figure 1)[2], to carry out the reduction of some aromatic nitrocompounds using NaBH4 as the reducing agent, and to determine the kinetic features of th…

Binding properties of mono-6-amino-beta-cyclodextrin towards p-nitroaniline derivatives: a polarimetric study

GEL FLUORESCENTI SUPRAMOLECOLARI FORMATI DA DERIVATI DELLA RIBOFLAVINA E β-CICLODESTRINE

2021

Cyclodextrins in capillary electrophoresis: Recent developments and new trends

2014

Despite the fact that extensive research in the field of separations by capillary electrophoresis (CE) has been carried out and many reviews have been published in the last years, a specific review on the use and future potential of cyclodextrins (CDs) in CE is not available. This review focuses the attention in the CD-CE topic over the January 2013-February 2014 period (not covered by previous more general CE-reviews). Recent contributions (reviews and research articles) including practical uses (e.g. solute-CD binding constant estimation and further potentials; 19% of publications), developments and applications (mainly chiral and achiral analysis; 38 and 24% of publications, respectively…

Fast-multivariate optimization of chiral separations in capillary electrophoresis: Anticipative strategies

2014

Abstract The design of experiments (DOE) is a good option for rationally limiting the number of experiments required to achieve the enantioresolution (Rs) of a chiral compound in capillary electrophoresis. In some cases, the modeled Rs after DOE analysis can be unsatisfactory, maybe because the range of the explored factors (DOE domain) was not the adequate. In these cases, anticipative strategies can be an alternative to the repetition of the process (e.g. a new DOE), to save time and money. In this work, multiple linear regression (MLR)-steepest ascent and a new anticipative strategy based on a multiple response-partial least squares model (called PLS2-prediction) are examined as post-DOE…

Olefin metathesis reactions with fluorinated substrates, catalysts, and solvents.

2014

Solubility and solvation features of native cyclodextrins in 1-ethyl-3-methylimidazolium acetate

2022

The comprehension of the mechanism entailing efficient solvation of cyclodextrins (CD) by green solvents is of great relevance to boost environmentally sustainable usages of smart supramolecular systems. Here, 1-ethyl-3- methylimidazolium acetate, an ecofriendly ionic liquid (IL), is considered as an excellent solvent for native CDs. This IL efficiently dissolves up to 40 wt.% β- and γ-CD already at ambient temperature and X-ray scattering indicates that CDs do not tend to detrimental flocculation under these drastic concentration conditions. Simu- lation techniques reveal the intimate mechanism of CD solvation by the ionic species: while the strong hydrogen bonding acceptor acetate anion i…

A new heuristic algorithm for the analysis of NMRD dispersion curves

Regression analysis of the NMRD dispersion curves obtained by the FFC-NMR relaxometric technique involves several conceptual and practical issues, which must be carefully addressed in order to gain reliable information on the system studied. Indeed, particular caution is needed when the FFC technique is applied to the investigation of complex systems such as polymeric matrixes, porous materials, food samples, and so on. In these cases, and in general whenever a rigorous approach based on a suitable physical modelization of the system is not available, data analysis must be performed by means of a “model–free” approach. Moving forward from previous literature, in the present communication we…