Syntheses and characterisation of novel cyclodextrin vinyl derivatives from cyclodextrin-nitrophenol-derivatives

Mass Spectrometry of Esterified Cyclodextrins

Cyclodextrins are cyclic oligosaccharides that have received special attention due to their cavity-based structural architecture that imbues them with outstanding properties, primarily related to their capacity to host various guest molecules, from low-molecular-mass compounds to polymers. Cyclodextrin derivatization has been always accompanied by the development of characterization methods, able to unfold complicated structures with increasing precision. One of the important leaps forward is represented by mass spectrometry techniques with soft ionization, mainly matrix-assisted laser desorption/ionization (MALDI) and electrospray ionization (ESI). In this context, esterified cyclodextrins (ECDs) benefited also from the formidable input of structural knowledge, thus allowing the understanding of the structural impact of reaction parameters on the obtained products, especially for the ring-opening oligomerization of cyclic esters. The current review envisages the common mass spectrometry approaches such as direct MALDI MS or ESI MS analysis, hyphenated liquid chromatography-mass spectrometry, and tandem mass spectrometry, employed for unraveling the structural features and particular processes associated with ECDs. Thus, the accurate description of complex architectures, advances in the gas phase fragmentation processes, assessment of secondary reactions, and reaction kinetics are discussed in addition to typical molecular mass measurements.

Mono-6-Substituted Cyclodextrins-Synthesis and Applications

Cyclodextrins are well known supramolecular hosts used in a wide range of applications. Monosubstitution of native cyclodextrins in the position C-6 of a glucose unit represents the simplest method how to achieve covalent binding of a well-defined host unit into the more complicated systems. These derivatives are relatively easy to prepare; that is why the number of publications describing their preparations exceeds 1400, and the reported synthetic methods are often very similar. Nevertheless, it might be very demanding to decide which of the published methods is the best one for the intended purpose. In the review, we aim to present only the most useful and well-described methods for preparing different types of mono-6-substituted derivatives. We also discuss the common problems encountered during their syntheses and suggest their optimal solutions.

Thermoresponsive chiral stationary phase functionalized with the copolymer of β-cyclodextrin and N-isopropylacrylamide for high performance liquid chromatography

A novel chiral stationary phase (CSP) was prepared through the reaction of surface-initiated atom transfer radical polymerization (ATRP) by the copolymerization of thermoresponsive N-isopropylacrylamide (NIPAM) and β-cyclodextrin (β-CD) on the silica beads for high performance liquid chromatography (HPLC). X-ray photoelectron spectroscopy (XPS), elemental analysis (EA), Fourier transform infrared spectrometry (FT-IR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) were applied to characterize the surface property of modified silica. Thermoresponsive modulation for the effect on enantioselectivity were investigated with chiral reagents including 1-phenyl-1-propanol, styrene oxide, 2-phenylpropionic acid and commercial chiral drugs comprising ibuprofen and labetalol hydrochloride. The column efficiency was evaluated by chromatographic parameters including retention factor (k), selective factor (α), resolution (R_s), plate number (N) and peak tailing factor (T_f). The results showed that five chiral solutes could be separated on the prepared smart column. And the selectivity of these compounds could be modulated by regulating the column temperature. It was contributed to the thermoresponsive NIPAM assisting β-CD to separate these chiral compounds. These results indicated that the thermoresponsive CSP would be a potential tool for separation of hydrophilic and hydrophobic chiral drugs and this paper provided a novel method for chiral separation in the future.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: an update for 2009-2010

This review is the sixth update of the original article published in 1999 on the application of MALDI mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2010. General aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, arrays and fragmentation are covered in the first part of the review and applications to various structural typed constitutes the remainder. The main groups of compound that are discussed in this section are oligo and polysaccharides, glycoproteins, glycolipids, glycosides and biopharmaceuticals. Many of these applications are presented in tabular form. Also discussed are medical and industrial applications of the technique, studies of enzyme reactions and applications to chemical synthesis.

Applications of isothermal titration calorimetry in pure and applied research--survey of the literature from 2010

Isothermal titration calorimetry (ITC) is a biophysical technique for measuring the formation and dissociation of molecular complexes and has become an invaluable tool in many branches of science from cell biology to food chemistry. By measuring the heat absorbed or released during bond formation, ITC provides accurate, rapid, and label-free measurement of the thermodynamics of molecular interactions. In this review, we survey the recent literature reporting the use of ITC and have highlighted a number of interesting studies that provide a flavour of the diverse systems to which ITC can be applied. These include measurements of protein-protein and protein-membrane interactions required for macromolecular assembly, analysis of enzyme kinetics, experimental validation of molecular dynamics simulations, and even in manufacturing applications such as food science. Some highlights include studies of the biological complex formed by Staphylococcus aureus enterotoxin C3 and the murine T-cell receptor, the mechanism of membrane association of the Parkinson's disease-associated protein α-synuclein, and the role of non-specific tannin-protein interactions in the quality of different beverages. Recent developments in automation are overcoming limitations on throughput imposed by previous manual procedures and promise to greatly extend usefulness of ITC in the future. We also attempt to impart some practical advice for getting the most out of ITC data for those researchers less familiar with the method.