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8 pages, 9 figures, 1 tables.-- Printed version published in May 2010., Current developments in active food packaging are focusing on incorporating agents into the polymeric package walls that will release or retain substances to improve the quality, safety and shelf-life of the food. Because cyclodextrins are able to form inclusion complexes with various compounds, they are of potential interest as agents to retain or scavenge substances in active packaging applications. In this study, β-cyclodextrin (βCD) was successfully immobilized in an ethylene-vinyl alcohol copolymer with a 44% molar percentage of ethylene (EVOH44) by using regular extrusion with glycerol as an adjuvant. Films with 10%, 20% and 30% of βCD were flexible and transparent. The presence of the agent slightly increased the glass-transition temperature and the crystallinity percentage of the polymer, that is to say, it induced some fragility and a nucleating effect. The water vapor, oxygen and carbon dioxide barrier properties of the materials containing βCD were determined and compared with those of the pure polymeric material. Permeability to these three permeants increased with the addition of βCD due to the presence of discontinuities in the matrix and to the internal cavity of the oligosaccharide. Also the CO2/O2 permselectivity increased with the addition of βCD. Finally, the potential effect of the composites in the food aroma was analyzed. The materials with βCD preferentially sorbed apolar compounds such as terpenes. This characteristic could be useful in active packaging applications for preferentially retaining undesired apolar food components like hexanal or cholesterol., The authors acknowledge the financial support of the Spanish Ministry of Science and Innovation, projects AGL2006-02176 and Fun-C-Food CSD2007-00063, and the C. L-d-D fellowship (FPU program).

This study analyzed the assimilation efficiency of carotenoids when they are delivered as inclusion complexes with β-cyclodextrin (CyDIC) in water. The in vitro assimilation model used was the brush border membrane vesicles (BBMV) system in which the BBMVs were incubated with CyDIC. Carotenoid suspensions in Tween were used as a reference. Regardless of the form in which the carotenoids were delivered to the BBMV preparation, a higher assimilation efficiency was observed for carotenes than for the xanthophyll lutein. At the highest donor solution concentration, supplying carotenoids in CyDIC produced a significant increase in carotenoid assimilation compared to the corresponding carotenoid suspensions in Tween. The assimilation process using CyDIC takes place by means of a dissociation process in which the carotenoids are released from the β-cyclodextrin to later be assimilated. At the highest concentration of CyDIC in the donor solution, the dissociation equilibrium will be shifted toward the free forms of the complex, thus increasing the amount of carotenoids available for assimilation. In another set of experiments, the effect of high-density lipoproteins as activity inhibitors for the receptors involved in carotenoid assimilation was analyzed. In carotenoid suspensions in Tween, with an inhibitor, a significant decrease in the assimilated quantity compared was observed with values reached without the inhibitor. Lutein presented the most significant decrease (70%). The fact that complete inhibition was not reached suggests that both simple and facilitated diffusion contributes to the assimilation process. When the donor solution composed of CyDIC and inhibitor was added, significant increases were observed in β-carotene and lycopene assimilation for all concentrations and in lutein for the highest concentration. This effect is due to the exchange between lipoprotein lipid components and CyDIC, which promotes the dissociation and liberation processes of the carotenoid, which then becomes available for assimilation., The support of the Ministerio de Educación y Ciencia (Spanish Government, Project AGL2007-61146/ALI) and the Consejería de Innovación Ciencia y Empresa (Junta de Andalucía, Project AGR-03025) is acknowledged. E.F.-G. is a research fellow of the Spanish National Research Council (I3P, a predoctoral program cofinanced by the European Social Fund). I.C.-L. is a research fellow of the Junta de Andalucía (Proyecto de Excelencia, predoctoral program cofinanced by the European Social Fund).

8 páginas, 7 figuras, 2 esquemas., It is generally recognized that the major obstacle to efficient gene delivery is cellular internalization and endosomal escape of the DNA. Recently, we have developed a modular strategy for the preparation of well-defined polycationic amphiphilic cyclodextrins (paCDs) capable of complexing and compacting DNA into homogeneous nanoparticles (< 70 nm). Since paCDs resemble both cationic polymers and cationic lipids, it is conceivable that the corresponding pDNA–paCD nanoparticles (CDplexes) might use the cell internalization and endosomal escape mechanisms described for both lipoplexes and polyplexes. To verify this hypothesis, we have now investigated the uptake and transfection efficiencies of CDplexes in the presence of several inhibitors of endocytosis, namely chlorpromazine, genistein, dynasore and methylated β-cyclodextrin (MbCD). Our data show that CDplexes obtained from paCD 1, which ranks among the most efficient paCD gene vectors reported up to date, are internalized by both clathrin-dependent (CDE) and clathrin-independent endocytosis (CIE), both processes being cholesterol- and dynamin-dependent. We observed that the largest fraction of gene complexes is taken up via CDE, but this fraction is less relevant for transfection. The smaller fraction that is internalized via the CIE pathway is predominantly responsible for successful transfection., This work was supported by the Spanish Ministerio de Innovación y Ciencia (MICINN, contract numbers CTQ2006-15515-C02-01/BQU and CTQ2007-61180/PPQ) and the Junta de Andalucía (P06-FQM-01601 and P07-FQM-2774). ADM is grateful to the CSIC for a pre-doctoral fellowship. DV is a doctoral fellow of the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT), Belgium. We gratefully acknowledge the European Commission for funding through the Integrated 6th Framework Programme MediTrans and the Lab of Pharmaceutical Biotechnology (Ghent University) of Prof. D. Deforce for the access to their flow cytometer.

We describe the methods used in our laboratory for the analysis of single nucleic acid molecules with protein nanopores. The technical section is preceded by a review of the variety of experiments that can be done with protein nanopores. The end goal of much of this work is single-molecule DNA sequencing, although sequencing is not discussed explicitly here. The technical section covers the equipment required for nucleic acid analysis, the preparation and storage of the necessary materials, and aspects of signal processing and data analysis. Book subtitle: SUPER-RESOLUTION, PARTICLE TRACKING, MULTIPARAMETER, AND FORCE BASED METHODS ispartof: METHODS IN ENZYMOLOGY, VOL 475: SINGLE MOLECULE TOOLS, PT B pages:591-623 ispartof: Methods in Enzymology vol:474 pages:591-623 ispartof: location:United States status: published

International audience; alpha-Cyclodextrins (alpha-CDs) have the ability to form inclusion complexes with poly(ethylene oxide) (PEO) polymer chains. These pseudo-polyrotaxanes (PPRs) can be obtained by quenching an alpha-CD/PEO mixture in water from 70 degrees C down to a lower temperature (typically in the range from 5 to 30 degrees C) thanks to favorable interactions between alpha-CD cavities and PEO chains. Moreover, starting from a liquid alpha-CD/PEO mixture at a total mass fraction of 15% w/w at 70 degrees C, the formation of PPRs with time at a lower temperature induces a white physical gel with time, and phase separation is observed. We established that PPR molecules are exclusively found in the precipitated phase although unthreaded alpha-CD molecules and unthreaded PEO chains are in the liquid phase. At 30 degrees C, the physical gel formation is much slower than at 5 degrees C. At 30 degrees C, we established that, in a first step, alpha-CDs thread onto PEO chains, forming PPR molecules which are not in good solvent conditions in water. At a higher length scale, rapid aggregation of the PPR molecules occurs, and threaded alpha-CD-based nanocylinders form (cylinder length L 5.7 nm and cylinder radius R = 4.7 nm). At a higher length scale, alpha-CD-based nanocylinders associate in a Gaussian way, engendering the formation of precipitated domains which are responsible for the high turbidity of the studied system. At the end of this first step (i.e., after 20 min), the system still remains liquid and the PPRs are totally formed. Then, in a second step (i.e., after 150 min), the system undergoes its reorganization characterized by a compacity increase of the precipitated domains and forms a physical gel. We found that PPRs are totally formed after 20 min at 30 degrees C and that the system stays in a nongel state up to 150 min. This opens new perspectives regarding the PPR chemical modification: between these two characteristic times, we can easily envisage an efficient chemical modification of the PPR molecules in water, as for instance,in end-capping reaction leading to the synthesis of polyrotaxanes.

An emerging area of biosensors is based on the use of structures provided by recent advances of Nanotechnology such as nanowires, nanotubes and nanopores. Among them, the integration of natural nanopores such as ion channels with electronics is a promising approach to develop rapid, sensitive and reliable biosensors able to detect low concentration of target molecules or DNA sequencing. This paper presents a compact and low-cost system able to readout, process and record current in the pA range, provided by biological or synthetic nanopores. The approach is based on the idea that by processing the outputs of a large amount of single- molecule nanosensors would result in a significant increase of resolution and signal-to-noise ratio. The approach consists of an electronic interface able to detect current-based array of nanosensors, where the management of very large amount of data is critical for the readout process. As working example, we acquired the single molecule signals derived from non-covalent bindings between single α-hemolysin pores, embedded into an artificial lipid bilayer, and β-cyclodextrin molecules. The system embeds the electronic readout with the microfluidic where is placed the nanosensor array. The electronic interface is a 0.5mm2 current amplifier based on an array of ΣΔ converters. Then the high rate data streams are processed and downsampled by a DSP that communicates with a PC via a USB interface for data processing and storage.

Coffee brew is rich in chlorogenic and cinnamic acids, potent antioxidants. Its interaction with beta-cyclodextrin leads to formation of inclusion complexes which affect the physicochemical properties of the guest molecule. We investigated spectral changes in coffee-originated phenols, chlorogenic (CHA) and caffeic (CA) acids, due to complexation with beta-cyclodextrin (betaCD) in aqueous solutions and studied thermodynamic properties of the complexes formed. The spectroscopic data (absorption and fluorescence) were used for deducing the position of both phenols inside the beta-cyclodextrin cavity, as well as to calculate the binding constants of the complexes. The obtained data indicate the formation of a 1:1 complex between betaCD and CHA or CA. The temperature-dependence of the latter allowed the calculation of thermodynamic parameters (Δ H , Δ S and Δ G ) of the complexation. The negative values of all the thermodynamic parameters indicated that the formation of these inclusion complexes was an enthalpy-driven process in which a crucial role is played by weak van der Waals forces and hydrogen bonds. Molecular modelling confirmed experimental observations that, in aqueous phase, betaCD–CHA and –CA complexes are stable and energetically favourable, and additionally provided information regarding conformation and interaction between atoms forming the complexes. The experimental data were used to characterise the molecular mechanism of the complexation.

International audience; The UV-spectra of pure caffeine were measured and two quite differentiated hyper- or hypo-chromic effects were observed as concentration was increased. The first one was explained as due to caffeine-water molecule interaction and the second as originating from dimer formation and staking of caffeine molecules. The effects of sucrose and beta-cyclodextrin on the hydration and the self-association of caffeine were also examined by UV spectroscopy. Sucrose was found to enhance the self-association of caffeine molecules by attracting and structuring water molecules around itself. The caffeine-caffeine hydrophobic interactions were promoted in such hydrophilic environment and so was the stacking. The molecular aggregation leads to reducing the electronic mobility and so is the case for the mesomeric effect in the heterogeneous cycle. This could explain the hypo-chromic phenomenon observed when sucrose concentration was increased. beta-Cyclodextrin shows a distinct behaviour because of its ability to form inclusion complexes with various hydrophobic guest molecules. This ability enhances the solubility of caffeine molecules throughout the inclusion interactions and prevents the caffeine self-association.

The photophysical and spectroscopic characterization of four new dimeric bis(BF2)-2,2 '-bidipyrrins (BisBODIPYs) recently synthesized and characterized (Chem. Eur. J., 2008, 14, 2976-2983) has been undertaken along with that of the component BODIPY monomers. The monomers display the typical photophysical properties of this family; (i) narrow and intense single absorption band in the visible range at 530 nm; (ii) intense, solvent independent emission (Phi(fl) ca. 1); (iii) narrow emission band with a 200-400 cm(-1) Stokes shifted emission, independent of solvent polarity; (iv) no absorption features for the singlet excited state; (v) very little triplet yield and no ability to sensitize singlet oxygen. The absorption spectra of the corresponding new dimers exhibit split band maxima in the visible range at about 490 and 560 nm, corresponding to an exciton splitting of ca. 2600 cm(-1). The luminescence in toluene is strong (Phi(fl) ca. 0.7, tau = 3.4 ns), broad and Stokes shifted by ca. 2200 cm(-1), but both luminescence yield and Stokes shift are solvent polarity dependent; F. < 0.1, tau < 1 ns and the Stokes shift is close to 2700 cm(-1) in acetonitrile. Solvent viscosity does not appear to play an important role and freezing of the solvents to 77 K in a solid matrix cancels the differences in luminescence parameters. Singlet and triplet excited state absorbance was measured in toluene and acetonitrile and the ability of these new dyes to sensitize singlet oxygen was examined. The nature and dynamics of the excited state is discussed in comparison with the monomers properties and with some intra- or inter-molecular BODIPY dimers reported in the literature. Potential applications of these new dyes with respect to BODIPYs are pointed out on the basis of their spectroscopic and photophysical properties.

Orientador: Inez Valeria Pagotto Yoshida Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica Resumo: No presente trabalho obteve-se híbridos de siloxano e b-ciclodextrina (b-CD). Baseando-se na comprovada reatividade das ciclodextrinas frente a grupos isocianatos, sintetizou-se um híbrido de b-ciclodextrina e siloxano, pela reação da b-ciclodextrina com g-isocianatopropiltrietoxissilano (IPTS), formando uma ligação uretana entre o silano e a b-ciclodextrina. O alcoxissilano, posteriormente hidrolisado, deu origem a um material resinoso do tipo polissilsesquioxano (PSS) modificado por b-ciclodextrina. O mesmo alcoxissilano foi também submetido à condensação com poli(dimetilsiloxano) contendo ¿Si(CH3)2-OH em finais de cadeia, dando origem a uma rede polimérica, também de aspecto resinoso, contendo nos nós de reticulação a b-cyclodextrin. Os materiais obtidos foram caracterizados estruturalmente por espectro infravermelho (IV), ressonância magnética nuclear de C (RMN C) e de Si (RMN Si) e análise por difração de raios X (DRX). O comportamento térmico dos materiais foi analisado por termogravimetria (TGA). A capacidade formadora de complexos de inclusão das ciclodextrinas inseridas no polímero PSS-b-CD foi avaliada pela inclusão de fenolftaleína, monitorada por espectrofotometria na região UV-vis e a difusão de água pelo material foi avaliada por ensaios de intumescimento. A morfologia dos filmes dos materiais preparados foi analisada por microscopia eletrônica de varredura (SEM). Abstract: In this study, hybrid polymers derived from siloxane and b-cyclodextrin (b-CD) were obtained, by reaction of b-CD with g-isocianatepropyltriethoxysilane (IPTS), forming a urethane bond between these components. The resulting alkoxysilane was hydrolyzed generating b-CD-modified polysilsesquioxane resin (b-CD-PSS). The alkoxysilane was also submitted to condensation with poly(dimethylsiloxane) with ¿ Si(CH3)2-OH end groups, giving rise to a resinous polymeric network. These materials were characterized by infrared spectrum, C and Si nuclear magnetic resonance and X ray diffraction. The thermal behavior was analyzed by thermogravimetry. The capability of b-CD grafted in the siloxane polymers to form inclusion complexes was evaluated by the formation of b-CD-phenolphthalein, by UV-vis sectra. The ability of water diffusion into b-CD-PSS film was evaluated by swelling measurement. b-CD modified siloxanes were able to form films and their morphologies were evaluated by scanning electron microscopy. Mestrado Química Inorgânica Mestre em Química

Second-order rate constants and isobaric activation parameters for the intermolecular Diels-Alder reactions of cyclopentadiene with alkyl vinyl ketones (2a,b) and 5-substituted-1,4-naphthoquinones (3a-c) as well as for the intramolecular Diels-Alder reaction of N-furfuryl-N-methylmaleamic acid (4) were determined in water, monohydric alcohols, and highly aqueous solutions containing monohydric alcohols and other organic cosolvents. The intermolecular as well as the intramolecular Diels-Alder reaction are characterized by large rate accelerations upon going from an organic solvent to water as the reaction medium. A model for solvation effects on rate constants for Diels-Alder reactions in aqueous solutions is developed. The typical, huge rate enhancements for Diels-Alder reactions in water and in highly aqueous binary mixtures are significantly sensitive to substituent effects and are discussed in terms of enforced pairwise hydrophobic interactions between diene and dienophile.

1 - Article; The solid state structures of the complexes between antiseptic chlorhexidine and three anionic calix[4] arene derivatives are described. Each of the three calixarenes shows typical self-organisation in the solid-state that will further impose a specific complexation of the active molecule in the co-crystal.

The field of application of solid-state NMR to the study of supramolecular systems is growing rapidly, with many research groups involved in the development of techniques for the study of crystalline and amorphous phases. This Feature Article aims to provide an overview of the recent contributions of our research group to this field, paying particular attention to the study of the weak interactions such as hydrogen bonds in supramolecular systems through solid-state NMR investigations. The structure and dynamic behaviour of selected host-guest systems will be also discussed.

Synthesis, antioxidant properties and resistance to carnosinase hydrolysis of histidine-containing dipeptides are reported in this study. Carnosine (beta-alanyl-l-histidine), homocarnosine (gamma-aminobutyryl-l-histidine) and anserine (beta-alanyl-3-methyl-l-histidine) were covalently derivatized with beta-cyclodextrin to form different OH- or NH-bound conjugates. Mass spectroscopic and (1)H NMR data were used to determine the structure and the purity of the various beta-cyclodextrin derivatives. The inhibitory effect towards oxidation of human LDL induced by Cu(2+) ions, was estimated by measuring malondialdehyde formation as a function of increasing concentrations of these newly synthesized compounds (the beta-cyclodextrin-anserine conjugated in 3 had the highest antioxidant effect). All derivatives had higher antioxidant effects than those of the corresponding free histidine-containing dipeptides. Resistance to rat brain carnosinase hydrolysis of the most active derivatives indicated that these compounds are good candidates for further studies in more complex cellular and animal models. Their possible applications for remedies in neurodegenerative disorders, such as Alzheimer's and Parkinson's diseases, are discussed.

Purpose Lipid rafts are cholesterol enriched microdomains that colocalize signaling pathways involved in cell proliferation, metastasis, and angiogenesis. We examined the effect of methyl-β-cyclodextrin (MβCD)-mediated cholesterol extraction on the proliferation, adhesion, invasion, and angiogenesis of triple negative breast cancer (TNBC) cells. Methods We measured cholesterol and estimated cell toxicity. Detergent resistant membrane (DRM) and non-DRM fractions were separated using the OptiPrep gradient method. Cell cycles stages were analyzed by flow cytometry, apoptosis was assessed using the TdT-mediated dUTP nick end-labeling assay, and metastasis was determined using a Matrigel invasion assay. Neo-vessel pattern and levels of angiogenic modulators were determined using an in vitro angiogenesis assay and an angiogenesis array, respectively. Results The present study found that the cholesterol-depleting agent MβCD, efficiently depleted membrane cholesterol and caused concentration dependent (0.1-0.5 mM) cytotoxicity compared to nystatin and filipin III in TNBC cell lines, MDA-MB 231 and MDA-MB 468. A reduced proportion of caveolin-1 found in DRM fractions indicated a cholesterol extraction-induced disruption of lipid raft integrity. MβCD inhibited 52% of MDA-MB 231 cell adhesion on fibronectin and 56% of MDA-MB 468 cell adhesion on vitronectin, while invasiveness of these cells was decreased by 48% and 52% respectively, following MβCD treatment (48 hours). MβCD also caused cell cycle arrest at the G2M phase and apoptosis in MDA-MB 231 cells (25% and 58% cells, respectively) and in MDA-MB 468 cells (30% and 38% cells, respectively). We found that MβCD treated cells caused a 52% and 58% depletion of neovessel formation in both MDA-MB 231 and MDA-MB 468 cell lines, respectively. This study also demonstrated that MβCD treatment caused a respective 2.6- and 2.5-fold depletion of tyrosine protein kinase receptor (TEK) receptor tyrosine kinase levels in both TNBC cell lines. Conclusion MβCD-induced cholesterol removal enhances alterations in lipid raft integrity, which reduces TNBC cell survival.

Three host-guest systems have been characterized using surface tension (sigma), calorimetry, and molecular dynamics simulations (MD). The hosts were three native cyclodextrins (CD) and the guest the non-ionic carbohydrate surfactant octyl-beta-d-glucopyranoside. It is shown that, for any host-guest system, a rough screening of the most probable complex stoichiometries can be obtained in a model free form, using only calorimetric data. The sigma data were analyzed using a model that includes a newly proposed adsorption isotherm. The equilibrium constants for several stoichiometries were simultaneously obtained through fitting the sigma data. For alpha- and beta-CD, the predominant species is 1:1 and to a lesser extent 2:1, disregarding the existence of the 1:2. For gamma-CD, the 1:2 species dominates, the other two being also present. In an attempt to confirm these results, 10 ns MD simulations for each CD were performed using seven different starting conformations. The MD stable conformations agree with the results found from the experimental data. In one case, the spontaneous dissociation-formation of a complex was observed. Analysis of the trajectories indicates that hydrophobic interactions are primarily responsible for the formation and stability of the inclusion complexes. For the 2:1 species, intermolecular H-bonds between CD molecules result in a tight packed structure where their original truncated cone shape is lost in favor of a cylindrical geometry. Together, the results clearly demonstrate that the often used assumption of considering only a 1:1 species is inappropriate.

The phenanthroline systems are frequently employed in complexometric reactions. Their complex compounds are used in wide range of research, from quantitative analytical chemistry to study of reactions in living organisms. Because of their conjugate bonds they show strong absorption signals in IR and UV spectrum and therefore are suitable for spectroscopic study. There are nitrogen atoms present in the structure so they act as weak base. The system 5, 6-phenanthroline-trichloroacetic acid (5, 6-PHEN-TCA) was investigated by IR and UV spectrometry in dichloromethane solutions (CH2Cl2). Carboxyl peaks around 1700 cm− 1 were primarily monitored, while UV spectra showed changes of 5, 6-PHEN peaks, depending in what ratio were acid and base. It was found that TCA exists in the monomeric and dimeric forms and that monomeric form interacts with 5, 6-PHEN by forming complex. When an acid is in excess (ratio 5, 6-PHEN:TCA = 1:2 ; 1:4) there si significant change in color of solution of 5, 6-PHEN. Protonation of 5, 6-PHEN was verified with X-ray structure analysis. 5, 6-PHEN:TCA = 1:2 complex is actually a salt in which a cation is 5, 6-PHEN with one nitrogen atom protonated while an anion is trichloroacetat. The other molecule of TCA is undissociated.

A detailed characterization of a host-guest supramolecular copolymer, formed by adamantane and beta-cyclodextrin dimers (Ad(2) and beta CD2, respectively) in aqueous solution, has been carried out by combining small-angle X-ray scattering and light scattering experiments with molecular dynamics (MD) and Monte Carlo (MC) simulations. First, the solutions of the monomers were studied by a straightforward analysis of the scattering data. Afterward, the complex given by Ad(2) and two beta-cyclodextrin molecules was investigated by correlating scattering results and MD simulations, to characterize the host-guest linkage. Finally, a detailed interpretation of the polymer scattering data was achieved by MC simulations. These simulations were performed on a single supramolecular aggregate and, in view of its peculiar shape, the complete polymer structure was considered without resorting to more general but simplified chain models. The comparison between simulations with and without excluded volume interaction points out that, at our ionic strength (sodium azide 150 mM), the polymer is close to the theta condition. Fits by reverse MC methods show that the polymer presents a shrunk conformation in solution, but it does not close in stable cyclic structures, as generally hypothesized for this kind of small oligomer. However, a polymerization degree of about 8 (4 Ad(2) and 4 beta CD2) was estimated which does not show any concentration dependence.

Raman spectroscopy has been applied to the study of interactions involved in the formation of inclusion complexes between cyclodextrins and indomethacin. Raman spectra of free molecules and of their inclusion complexes have been recorded in the energy ranges 10-50 and 100-3500 cm(-1), and significant energy shifts, intensity variations and broadening have been observed due to complexation. The experimental data have been interpreted by comparison with the results of numerical simulation.

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2007, Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2007, Bu çalışmanın amacı mayonezin, fonksiyonel özelliklerini koruyarak, fakat düşük kolesterol ve yağ içerikli ve fonksiyonel bir ürün haline getirilmesidir. Bu çalışmada, sıvı yumurta sarısında bulunan kolesterol, β-siklodekstrin kullanılarak ayrılmış ve bu ürün düşük kolesterollü ve düşük yağlı mayonez üretiminde kullanılmıştır. Üretilen mayonezin formülasyonundaki farklı yumurta sarısı ve ksantan gam seviyelerinin ürünün kompozisyon, renk, kolesterol miktarı ile fizikokimyasal ve reolojik özellikleri üzerine etkileri incelenmiştir. Formülasyonda ksantan gam %0,4 ve %0,7 oranlarında, yumurta sarısı ise %4, %6 ve %7,5 oranlarında yer almıştır. Sonuç olarak, düşük kolesterollü sıvı yumurta sarısında bulunan kolesterol %83 oranında azaltılmıştır. Düşük kolesterollü yumurta sarısının çiğ yumurta sarısı ve pastörize yumurta sarısına göre daha yüksek karbonhidrat (%2,2) içeriğine, daha yüksek kırmızılık değeri ile düşük parlaklık ve sarılık değerlerine sahip olduğu tespit edilmiştir. Buna göre mayonezin sabit ksantan gam miktarlarında (%0,5) artan yumurta sarısı miktarı ile parlaklık ve sarılık değerlerinde azalma kaydedilmiş ancak kırmızılık değerinde bir artış belirlenmiştir. Bu durum gam miktarının %0,7’ye çıkarılması halinde durum tersine dönmüştür. Ayrıca düşük kolesterollü ve düşük yağlı mayonezin tüm formülasyonlarının düşük yağlı mayoneze göre daha az yağ ve kolesterol içeriğine ve daha yüksek protein içerdiği belirlenmiştir. Tüm mayonezlerin tiksotropik akış davranışına sahip olduğu ve Herschel-Bulkley modeline uygunluğu belirlenmiştir., The goal of this study is to transform mayonnaise into a product containing low cholesterol and fat by keeping its functional properties. In this study, the cholesterol inside liquid egg yolk was removed by the use of β-cyclodextrin, and this material was used for the production of mayonnaise with reduced cholesterol and fat. The different xanthan gum and egg yolk levels in the formulation of the produced mayonnaise has been examined to see their effects on composition, color, cholesterol level, physicochemical and rheological properties of mayonnaise. In the formulation; we observe 0.4 % and 0.7 % xanthan gum and 4 %, 6 % and 7.5 % egg yolk. The result is; the rate of cholesterol in low cholesterol egg yolk has been reduced 83 %. We see that; in comparison with raw and pasteurized egg yolk, cholesterol reduced egg yolk has higher carbohydrate (2.2 %), higher a value, and lower L and b values. In accordance with this finding, we see that keeping the amount of xanthan gum fixed (0.5 %) and increasing the amount of egg yolk has resulted with reduced L and b values while no change occurred in a value. This situation changed when increasing the amount of xanthan gum, 0.7 %. Besides, all the formulations of less cholesterol and less fatted mayonnaise has less fat and cholesterol levels and higher protein levels in comparison with low fat Mayonnaise. All the mayonnaises conforms Heschel-Bulkley model and have thixotropic flow behavior., Yüksek Lisans, M.Sc.

Assessments of the risk connected to the contamination of soils and sediments should rely on a multidisciplinary approach based on both chemical and biological techniques (i.e., the sum of exposure and effects assessment). The dioxin-responsive, chemical-activated luciferase expression (DR-CALUX) bioassay is widely applied for evaluation of the toxicity of sediments after an exhaustive extraction of the contaminants, and results are used for risk assessment purposes. Approaches based on total extraction of contaminants do not take into account the importance of bioavailability and aging processes, thus leading to possible overestimations of risk. In the present work, an approach based on nonexhaustive extraction techniques in combination with an in vitro reporter gene assay was tested on sediment samples contaminated with dioxins, polycyclic aromatic hydrocarbons, polychlorinated biphenyls (PCBs), and other xenobiotics. Tenax and hydroxypropyl-beta-cyclodextrin (HPCD) extractions over time were carried out to determine the bioavailable fractions, whereas the residual fractions were determined by means of a microwave-assisted exhaustive extraction. For both fractions, contaminant concentrations were quantified by gas chromatography-mass spectrophotometry, and the toxic potency was determined by the DR-CALUX assay. Assessments of bioavailable fractions of PCBs by Tenax and HPCD gave comparable results and showed that after several years of aging, a considerable fraction (38-70% of the total content for different PCBs) is still available and ecotoxicologically relevant. Coupling of nonexhaustive extraction and bioanalyses leads to a more realistic and, generally, much lower estimated risk for the toxicity of the extracts as compared to commonly adopted exhaustive techniques.

Solutions composed of alpha-cyclodextrin (alpha-CD), water, and various methylpyridines, in particular, 4-methylpyridine (4MP), undergo reversible liquid-solid transitions upon heating, the crystalline solid phases undergoing further phase transformations at higher temperatures. This unusual behavior has been characterized by an ensemble of measurements, including solubility, differential scanning calorimetry, quasielastic neutron scattering, as well as x-ray powder diffraction. For the alpha-CD/4MP system five crystalline phases have been identified. The unit cell parameters and corresponding changes with temperature indicate a scenario for the crystallization process. A simple model is proposed that mimics the observed disorder-order transition. (c) 2006 American Institute of Physics.

A detailed NMR (¹H , COSY, ROESY) spectroscopic study of complexation of enalapril maleate with beta-cyclodextrin was carried out. The ¹H NMR spectrum of enalapril maleate confirmed the existence of cis-trans equilibrium in solution, possibly due to hindered rotation along the amide bond. The cis-trans ratio remained almost the same in the presence of beta-cyclodextrin but in one case it was found significantly different which suggests a catalytic role of beta-cyclodextrin in the isomerization. ¹H NMR titration studies confirmed the formation of an enalapril-beta-cyclodextrin inclusion complex as evidenced by chemical shift variations in the proton resonances of both the host and the guest. The stoichiometry of the complex was determined to be 2:1 (guest: host). The mode of penetration of the guest into the beta-cyclodextrin cavity as well as the structure of the complex were established using ROESY spectroscopy.

A new family of supramolecular systems based on a synthetic polyaminoacid and cyclic oligosaccharides such as beta-cyclodextrins (beta-CDs) was synthesised. The pharmaceutical potential of these systems arises from the proper combination between the complexing properties of cyclodextrins and the particular pharmacokinetic profile that can be obtained by using macromolecular conjugates with a biocompatible backbone. Five supramolecular conjugates were synthesised by using alpha,beta-polyaspartylhydrazide (PAHy) as a polymeric component and various amounts of two P-CD derivatives. In particular, by reaction of PAHy with beta-CD monoaldehyde, samples named as A(1), A(2) and A(3), bearing, respectively, 4.0, 7.5 and 10.7 mol% of beta-CDs were obtained. The reaction of PAHy with 6-[aminoethyl(4'-carboxybutanamide)]-beta-CD afforded samples named as B-1 and B-2, bearing, respectively, 1.8 and 2.6 mol% of beta-CDs linked to the polymer. The occurrence of the conjugation reactions as well as the evaluation of the amount of oligosaccharides conjugated to the polymeric backbone were confirmed by FT-IR, H-1 NMR, DSC, SEC analyses and viscosimetric measurements. Molecular weight values obtained by SEC analysis were in good agreement with the theoretical increase of molecular weight of PAHy due to the beta-CD moieties linked to the polymeric backbone. Fluorescence studies on the conjugate A(3) evidenced an interaction of a probe molecule with beta-CDs linked to PAHy greater than that found with beta-CDs alone and even in both cases the formation of a 1:1 host-guest complex occurs.

Vibrational properties of inclusion complexes with cyclodextrins are studied by means of Raman spectroscopy and numerical simulation. In particular, Raman spectra of the non-steroidal, anti-inflammatory drug indomethacin undergo notable changes in the energy range between 1600 and 1700 cm$^{-1}$ when inclusion complexes with cyclodextrins are formed. By using both \emph{ab initio} quantum chemical calculations and molecular dynamics, we studied how to relate such changes to the geometry of the inclusion process, disentangling single-molecule effects, from changes in the solid state structure or dimerization processes., Comment: 14 file figures

The methodology for the inclusion of tebuconazole in beta-cyclodextrin, spectroscopic characterization of the inclusion complex and its activity for the control of a major soilborne disease of wheat caused by Fusarium culmorum are reported. Controlled release measured by chemical shift of the diagnostic proton H3 and H5 of beta-cyclodextrin confirmed stability of the complex at the solid state and in aqueous solution. Greenhouse and field experiments were conducted on durum wheat (Triticum durum, cv Prometeo) sown in substrate or in soil artificially infested with a virulent strain of F. culmorum. The inclusion complex beta-cyclodextrin - tebuconazole, applied as seed dressing in combination or not with carboxymethylcellulose, reduced the disease inctidence caused by F. culmorum and improved grain yield, showing effects that were generally comparable to those observed upon application of a commercial formulation of tebuconazole.In the field experiment, only seed treatment with the inclusion complex beta-cyclodextrin - tebuconazole allowed an yield that was not different from that obtained from the uninoculated control. These results prove that by the use of the betaCD-TBC complex it is possible to control the release of tebuconazole without compromising its effectiveness.

Extending our investigations on environment protection by agrochemicals diffusion and accumulation, newly formed inclusion combinations of rimsulfuron into zeolite-NaY (Z-NaY) and beta-cyclodextrin (beta-CD) were studied and compared. The reactivity of the included herbicide under UV-irradiation and in the dark was assessed. Many guest/ host ratios were tested: the best results were found using 3 g (6.953 mmol) of rimsulfuron per kilogram of zeolite, with 80% inclusion success (5.562 mmol kg-(1)), and a 1: 2 molar ratio, 190 g of rimsulfuron per kilogram of beta-CD with 58% inclusion success. The herbicide Z-NaY-combined underwent rapid and effective (halflive 2-7 h) degradation either catalytically or photochemically, giving rise to different identified by-products. On the contrary, beta-CD was able to protect rimsulfuron totally both in the dark and under 24-h direct UV irradiation. On the basis of the obtained results, a different utilization of the two inclusion materials has been suggested.

Membranes and detergent-resistant membrane fractions isolated from human epidermoid carcinoma A431 cells after treatment with methyl-beta-cyclodextrin, a compound commonly used in pharmaceutical applications and in manipulation of membrane cholesterol content, display thermotropic transitions at about 15 degrees C and above 37 degrees C, respectively, when analyzed by differential scanning calorimetry. The transitions, absent in untreated cells, were reversible upon cycling through heating and cooling scans, and attributable to lipid components of the membranes, possibly sphingolipids. These results suggest that, after treatment with methyl-beta-cyclodextrin, membranes may show thermotropic transitions, an unusual feature for cellular bilayers, which is likely to influence biological functions.

The interaction between the anionic 5,10,15,20-tetrakis(4-sulfonatophenyl)-21H,23H-porphyrin (TPPS) and cationic vesicles formed by heptakis(2-omega-amino-O-oligo(ethylene oxide)-6-hexylthio)-beta-cyclodextrin (SC6CDNH2) has been investigated in detail through a combination of elastic light scattering (ELS), quasi-elastic light scattering (QELS), zeta potential measurements, and time-resolved fluorescence anisotropy. ELS experiments provided the first structural characterization of these cationic vesicles both in the absence and in the presence of TPPS porphyrin, modeling the system as a spherical particle described by a single thin shell form factor. The structure of mixed hetero-aggregates is modulated by charge and size of the two components as function of different porphyrin/cyclodextrin (CD) molar ratios. At the limiting molar ratio studied, the absolute value of zeta potential (/zeta/ = 12.5 mV) seems to be a reference value for the formation of stable colloidal CD vesicular aggregates at thermodynamic equilibrium. New insights on the structure of these heterotopic colloids have been obtained by analysis of rotational correlation times at different molar ratios exploiting time-resolved fluorescence anisotropy experiments. At high porphyrin loads, the anisotropy decays behave as monoexponentials and the rotational correlation times (1-2 ns) together with the r(0) values close to zero suggest the presence of small amounts of TPPS embedded in a hydrophobic environment either in monomeric or in aggregated form. At the lower porphyrin/CD molar ratios, the anisotropy decays exhibit a double-exponential behavior showing a predominant component with a slow rotational correlation time (20-25 ns) and limiting anisotropy values of approximately 0.15. This component has been assigned to molecules that are more stabilized onto the CD vesicles, that is, porphyrins embedded into the oligo-ethylene "wall" of the CD vesicles. Scanning near-field optical microscopy of the samples evaporated on glass surfaces gave further insights on the morphology and optical properties of these systems, confirming the embedding of TPPS on the vesicles and evidencing the role of the solvent.