Band 91, Heft 9

Reductive alkylation of the carbonyl group of carbohydrates with fluorescence or ionizing labels is a prerequisite for the sensitive analysis of carbohydrates by chromatographic and mass spectrometric techniques. Herein, 1-(2-aminoethyl)-3-methyl-1 H -imidazol-3-ium tetrafluoroborate ([MIEA][BF 4 ]) was successfully synthesized using tert -butyl N -(2-bromoethyl)carbamate and N -methylimidazole as starting materials. MIEA + was then investigated as a multifunctional oligosaccharide label for glycan profiling and identification using LC-ESI-ToF and by MALDI-ToF mass spectrometry. The reductive amination of this diazole with carbohydrates was exemplified by labeling N -glycans from the model glycoproteins horseradish peroxidase, RNase B, and bovine lactoferrin. The produced MIEA + glycan profiles were comparable to the corresponding 2AB labeled glycan derivatives and showed improved ESI-MS ionization efficiency over the respective 2AB derivatives, with detection sensitivity in the low picomol to the high femtomol range.

Chemical glycosylations occupy a central importance to synthesize tailor-made oligo- and polysaccharides of functional importance. Generation of the oxocarbenium ion or the glycosyl cation is the method of choice in order to form the glycosidic bond interconnecting a glycosyl moiety with a glycosyl/aglycosyl moiety. A number of elegant methods have been devised that allow the glycosyl cation formation in a fairly stream-lined manner to a large extent. The latent-active method provides a powerful approach in the protecting group controlled glycosylations. In this context, allyl glycosides have been developed to meet the requirement of latent-active reactivities under appropriate glycosylation conditions. Radical halogenation provides a newer route of activation of allyl glycosides to an activated allylic glycoside. Such an allylic halide activation subjects the glycoside reactive under acid catalysis, leading to the conversion to a glycosyl cation and subsequent glycosylation with a number of acceptors. The complete anomeric selectivity favoring the 1,2-trans-anomeric glycosides points to the possibility of a preferred conformation of the glycosyl cation. This article discusses about advancements in the selectivity of glycosylations, followed by delineating the allylic halogenation of allyl glycoside as a glycosylation method and demonstrates synthesis of a repertoire of di- and trisaccharides, including xylosides, with varied protecting groups.

The fully characterization of tumor associated antigens (TAAs) and of tumor associated carbohydrate antigens (TACAs) have opened the avenue of cancer immunotherapy. The intrinsic poor immunogenicity of TACAs, however, spotlighted the importance of multivalent presentation of the antigen(s) to trigger an immune response. Nanoparticles are excellent scaffolds for this purpose. Here we reported on the easy glycosylation of iron-based and biocompatible dextran-based nanoparticles with 1 , a mimetic of the TnThr antigen. The multivalent presentation of 1 induced the induction of TNF-α and IL-6/IL10, respectively. The multivalent glycosylation of silica nanoparticles (GSiNPs) was also performed and saccharide loading qualitative assessed by solid state NMR. Our results offer the proof of concept that biomolecules coating can also be investigated on solid system by NMR.

Structural and chemical alterations in living tissue are reflected in electrical impedance changes. However, due to the complexity of skin structure, the relation between electrical parameters and physiological/pathological conditions is difficult to establish. The impedance dispersion reflects the clinical status of the examined skin tissue and, therefore, it is frequently used in a non-invasive evaluation of exposing skin to various factors. The method has been used to assess the effect of the fish collagen on the skin of patients suffering from the leg ulcer. Therefore, from a number of different approaches to skin electrical impedance dispersion, the one considered to be safe was selected and applied. This paper presents a short review of different technical approaches to in vivo electrical impedance measurements, as well as an analysis of the results and the effect of fish collagen locally administered on human skin.

The present study was focused on the preparation and characterization of different topical oil in water emulsions based on natural ingredients such as collagen hydrolysate and vegetable oils mixtures. As oil phases, mixtures of coconut, almond, jojoba, avocado oils (in different ratios) were used while the water phase consisted in lavender water. As emulsifier, a plant based product containing glyceryl stearate and potassium stearate was incorporated (in the concentration range 4–5 %), while as rheology modifier xanthan gum was used (in the concentration range 0.2–1 %). As preservatives, Cosgard (containing benzyl alcohol, salicylic acid, glycerol, ascorbic acid) and mixtures of two essential oils (lemon and lavender) were selected. The designed formulations were assessed by means of their physico-chemical properties (pH, viscosity, thixotropic behavior), optical microscopy analysis and sensorial characteristics. The obtained emulsions were found to present pseudoplastic and thixotropic behaviors, adequate for cosmetic skin care product formulations.

Polylactide scaffolds were prepared for the cancellous bone regeneration by the phase inversion method with freeze-extraction variant. A preliminary investigation and the optimization of the process were performed. For the obtained scaffolds, regression equations determining the effect: PLLA concentration by weight in 1,4-dioxane; volume ratio of the porophore/PLLA solution in 1,4-dioxane; and implant-forming solution pouring temperature, on the open porosity and mass absorbability were determined. The conditions in which the obtained implants were characterized by the maximal absorbability with the open porosity greater than 90 % were obtained.

Body wash cosmetics are among the most common groups of cosmetics used by consumers. Faced with strong competition in the marketplace, cosmetic manufacturers search for innovative solutions both in terms of product composition and form. An example of an innovative technology which can be used in the production of body wash cosmetics is the process of coacervation which yields a concentrated body wash product. Another important aspect which needs to be considered in the formulation of body wash cosmetics is their safety of use. It is crucial to ensure that such cosmetic products do not induce skin irritations. At present, the most widespread method of reducing the skin irritation potential of cosmetic products is the use of surfactant mixtures. The study is an attempt to evaluate the effect of using polyvinylpyrrolidone in the formulations of model body wash cosmetics in the coacervate form on the skin irritation potential and basic quality determinants of body wash products. Polyvinylpyrrolidone was found to contribute to a significant reduction in the irritant effect, and the skin irritation potential decreased in proportion to increasing molecular mass of the polymer. The application of polyvinylpyrrolidone with the different molecular weight also has an impact on improving the foaming properties of model body wash cosmetics and the stability of foam they produce.

Novel functional polymeric microcapsules, based on modified azobenzene moieties, are exhaustively investigated, both from a theoretical and experimental points of view. Theoretical calculations and several measurements demonstrate that visible light can act as a trigger for release of encapsulated material, as a consequence of trans-cis isomerization which modifies microcapsule surface topography and can induce a “squeezing” release mechanism. Interfacial polymerization of an oil-in-water emulsion is performed and leads to core-shell microcapsules which are characterized by means of atomic force microscopy (AFM), optical microscopy (OM), scanning electron microscopy (SEM) and light scattering. These analyses put into evidence that microcapsules’ size and surface morphology are strongly affected by irradiation under visible light: moreover, these changes can be reverted by sample exposure to temperatures around 50°C. This last evidence is also confirmed by NMR kinetic analyses on modified azobenzene moiety. Finally, it is shown that these smart microcapsules can be successfully used to get a controlled release of actives such as fragrancies, as a consequence of visible light irradiation, as confirmed by an olfactive panel.