Phenolic compounds from Rosemary (Rosmarinus officinalis L.) attenuate oxidative stress and reduce blood cholesterol concentrations in diet-induced hypercholesterolemic rats

Abstract Background Phenolic compounds combine antioxidant and hypocholesterolemic activities and, consequently, are expected to prevent or minimize cardiometabolic risk. Methods To evaluate the effect of an aqueous extract (AQ) and non-esterified phenolic fraction (NEPF) from rosemary on oxidative stress in diet-induced hypercholesterolemia, 48 male 4-week old Wistar rats were divided into 6 groups: 1 chow diet group (C) and 5 hypercholesterolemic diet groups, with 1 receiving water (HC), 2 receiving AQ at concentrations of 7 and 140 mg/kg body weight (AQ70 and AQ140, respectively), and 2 receiving NEPF at concentrations of 7 and 14 mg/kg body weight (NEPF7 and NEPF14, respectively) by gavage for 4 weeks. Results In vitro, both AQ and NEPF had remarkable antioxidant activity in the 2,2-diphenyl-1-picrylhydrazyl (DPPH●) assay, which was similar to BHT. In vivo, the group that received AQ at 70 mg/kg body weight had lower serum total cholesterol (−39.8%), non-HDL-c (−44.4%) and thiobarbituric acid reactive substance (TBARS) levels (−37.7%) compared with the HC group. NEPF (7 and 14 mg/kg) reduced the tissue TBARS levels and increased the activity of tissular antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase). Neither AQ nor NEPF was able to ameliorate the alterations in the hypercholesterolemic diet-induced fatty acid composition in the liver. Conclusions These data suggest that phenolic compounds from rosemary ameliorate the antioxidant defense in different tissues and attenuate oxidative stress in diet-induced hypercholesterolemic rats, whereas the serum lipid profile was improved only in rats that received the aqueous extract.

Accuracy, precision and robustness of different methods to obtain samples from silages in fermentation studies

The objective of this study was to evaluate accuracy, precision and robustness of two methods to obtain silage samples, in comparison with extraction of liquor by manual screw-press. Wet brewery residue alone or combined with soybean hulls and citrus pulp were ensiled in laboratory silos. Liquor was extracted by a manual screw-press and a 2-mL aliquot was fixed with 0.4 mL formic acid. Two 10-g silage samples from each silo were diluted in 20 mL deionized water or 17% formic acid solution (alternative methods). Aliquots obtained by the three methods were used to determine the silage contents of fermentation end-products. The accuracy of the alternative methods was evaluated by comparing mean bias of estimates obtained by manual screw-press and by alternative methods, whereas precision was assessed by the root mean square prediction error and the residual error. Robustness was determined by studying the interaction between bias and chemical components, pH, in vitro dry matter digestibility (IVDMD) and buffer capacity. The 17% formic acid method was more accurate for estimating acetic, butyric and lactic acids, although it resulted in low overestimates of propionic acid and underestimates of ethanol. The deionized water method overestimated acetic and propionic acids and slightly underestimated ethanol. The 17% formic acid method was more precise than deionized water for estimating all organic acids and ethanol. The robustness of each method with respect to variation in the silage chemical composition, IVDMD and pH is dependent on the fermentation end-product at evaluation. The robustness of the alternative methods seems to be critical at the determination of lactic acid and ethanol contents.

Bioremediation of PAHs - Limitations and soultions

Introduction 1.1 Occurrence of polycyclic aromatic hydrocarbons (PAH) in the environment Worldwide industrial and agricultural developments have released a large number of natural and synthetic hazardous compounds into the environment due to careless waste disposal, illegal waste dumping and accidental spills. As a result, there are numerous sites in the world that require cleanup of soils and groundwater. Polycyclic aromatic hydrocarbons (PAHs) are one of the major groups of these contaminants (Da Silva et al., 2003). PAHs constitute a diverse class of organic compounds consisting of two or more aromatic rings with various structural configurations (Prabhu and Phale, 2003). Being a derivative of benzene, PAHs are thermodynamically stable. In addition, these chemicals tend to adhere to particle surfaces, such as soils, because of their low water solubility and strong hydrophobicity, and this results in greater persistence under natural conditions. This persistence coupled with their potential carcinogenicity makes PAHs problematic environmental contaminants (Cerniglia, 1992; Sutherland, 1992). PAHs are widely found in high concentrations at many industrial sites, particularly those associated with petroleum, gas production and wood preserving industries (Wilson and Jones, 1993). 1.2 Remediation technologies Conventional techniques used for the remediation of soil polluted with organic contaminants include excavation of the contaminated soil and disposal to a landfill or capping - containment - of the contaminated areas of a site. These methods have some drawbacks. The first method simply moves the contamination elsewhere and may create significant risks in the excavation, handling and transport of hazardous material. Additionally, it is very difficult and increasingly expensive to find new landfill sites for the final disposal of the material. The cap and containment method is only an interim solution since the contamination remains on site, requiring monitoring and maintenance of the isolation barriers long into the future, with all the associated costs and potential liability. A better approach than these traditional methods is to completely destroy the pollutants, if possible, or transform them into harmless substances. Some technologies that have been used are high-temperature incineration and various types of chemical decomposition (for example, base-catalyzed dechlorination, UV oxidation). However, these methods have significant disadvantages, principally their technological complexity, high cost , and the lack of public acceptance. Bioremediation, on the contrast, is a promising option for the complete removal and destruction of contaminants. 1.3 Bioremediation of PAH contaminated soil & groundwater Bioremediation is the use of living organisms, primarily microorganisms, to degrade or detoxify hazardous wastes into harmless substances such as carbon dioxide, water and cell biomass Most PAHs are biodegradable unter natural conditions (Da Silva et al., 2003; Meysami and Baheri, 2003) and bioremediation for cleanup of PAH wastes has been extensively studied at both laboratory and commercial levels- It has been implemented at a number of contaminated sites, including the cleanup of the Exxon Valdez oil spill in Prince William Sound, Alaska in 1989, the Mega Borg spill off the Texas coast in 1990 and the Burgan Oil Field, Kuwait in 1994 (Purwaningsih, 2002). Different strategies for PAH bioremediation, such as in situ , ex situ or on site bioremediation were developed in recent years. In situ bioremediation is a technique that is applied to soil and groundwater at the site without removing the contaminated soil or groundwater, based on the provision of optimum conditions for microbiological contaminant breakdown.. Ex situ bioremediation of PAHs, on the other hand, is a technique applied to soil and groundwater which has been removed from the site via excavation (soil) or pumping (water). Hazardous contaminants are converted in controlled bioreactors into harmless compounds in an efficient manner. 1.4 Bioavailability of PAH in the subsurface Frequently, PAH contamination in the environment is occurs as contaminants that are sorbed onto soilparticles rather than in phase (NAPL, non aqueous phase liquids). It is known that the biodegradation rate of most PAHs sorbed onto soil is far lower than rates measured in solution cultures of microorganisms with pure solid pollutants (Alexander and Scow, 1989; Hamaker, 1972). It is generally believed that only that fraction of PAHs dissolved in the solution can be metabolized by microorganisms in soil. The amount of contaminant that can be readily taken up and degraded by microorganisms is defined as bioavailability (Bosma et al., 1997; Maier, 2000). Two phenomena have been suggested to cause the low bioavailability of PAHs in soil (Danielsson, 2000). The first one is strong adsorption of the contaminants to the soil constituents which then leads to very slow release rates of contaminants to the aqueous phase. Sorption is often well correlated with soil organic matter content (Means, 1980) and significantly reduces biodegradation (Manilal and Alexander, 1991). The second phenomenon is slow mass transfer of pollutants, such as pore diffusion in the soil aggregates or diffusion in the organic matter in the soil. The complex set of these physical, chemical and biological processes is schematically illustrated in Figure 1. As shown in Figure 1, biodegradation processes are taking place in the soil solution while diffusion processes occur in the narrow pores in and between soil aggregates (Danielsson, 2000). Seemingly contradictory studies can be found in the literature that indicate the rate and final extent of metabolism may be either lower or higher for sorbed PAHs by soil than those for pure PAHs (Van Loosdrecht et al., 1990). These contrasting results demonstrate that the bioavailability of organic contaminants sorbed onto soil is far from being well understood. Besides bioavailability, there are several other factors influencing the rate and extent of biodegradation of PAHs in soil including microbial population characteristics, physical and chemical properties of PAHs and environmental factors (temperature, moisture, pH, degree of contamination). Figure 1: Schematic diagram showing possible rate-limiting processes during bioremediation of hydrophobic organic contaminants in a contaminated soil-water system (not to scale) (Danielsson, 2000). 1.5 Increasing the bioavailability of PAH in soil Attempts to improve the biodegradation of PAHs in soil by increasing their bioavailability include the use of surfactants , solvents or solubility enhancers.. However, introduction of synthetic surfactant may result in the addition of one more pollutant. (Wang and Brusseau, 1993).A study conducted by Mulder et al. showed that the introduction of hydropropyl-ß-cyclodextrin (HPCD), a well-known PAH solubility enhancer, significantly increased the solubilization of PAHs although it did not improve the biodegradation rate of PAHs (Mulder et al., 1998), indicating that further research is required in order to develop a feasible and efficient remediation method. Enhancing the extent of PAHs mass transfer from the soil phase to the liquid might prove an efficient and environmentally low-risk alternative way of addressing the problem of slow PAH biodegradation in soil.

Effetti del chitosano su composti polifenolici in colture cellulari di vite: aspetti molecolari e metabolici

Polyphenols, including flavonoids and stilbenes, are an essential part of human diet and constitute one of the most abundant and ubiquitous group of plant secondary metabolites. The level of these compounds is inducible by stress or fungal attack, so attempts are being made to identify likely biotic and abiotic elicitors and to better understand the underlying mechanism. Resveratrol (3,5,4’-trihydroxystilbene), which belongs to the stilbene family, is a naturally occurring polyphenol, found in several fruits, vegetables and beverages including red wine. It is one of the most important plant polyphenols with proved benefic activity on animal health. In the last two decades, the potential protective effects of resveratrol against cardiovascular and neurodegenerative diseases, as well as the chemopreventive properties against cancer, have been largely investigated. The most important source of polyphenols and in particular resveratrol for human diet is grape (Vitis vinifera). Since stilbenes and flavonoids play a very important role in plant defence responses and enviromental interactions, and their effects on human health seem promising, the aim of the research of this Thesis was to study at different levels the activation and the regulation of their biosynthetic pathways after chitosan treatment. Moreover, the polyphenol production in grape cells and the optimisation of cultural conditions bioreactor scale-up, were also investigated. Cell suspensions were obtained from cv. Barbera (Vitis vinifera L.) petioles and were treated with a biotic elicitor, chitosan (50 μg/mL, dissolved in acetic acid) to promote phenylpropanoid metabolism. Chitosan is a D-glucosamine polymer from fungi cell wall and therefore mimes fungal pathogen attack. Liquid cultures have been monitored for 15 days, measuring cell number, cell viability, pH and grams of fresh weight. The endogenous and released amounts of 7 stilbenes (trans and cis isomers of resveratrol, piceid and resveratroloside, and piceatannol), gallic acid, 6 hydroxycinnamic acids (trans-cinnamic, p-coumaric, caffeic, ferulic, sinapic and chlorogenic acids), 5 catechines (catechin, epicatechin, epigallocatechin-gallate (EGCG), epigallocatechin and epicatechin-gallate) and other 5 flavonoids (chalcon, naringenin, kaempferol, quercetin and rutin) in cells and cultural medium, were measured by HPLC-DAD analysis and total anthocyanins were quantified by spectrophotometric analysis. Chitosan was effective in stimulating trans-resveratrol endogenous accumulation with a sharp peak at day 4 (exceeding acetic acid and water controls by 36% and 63%, respectively), while it did not influence the production of the cis-isomer. Compared to both water and acetic acid controls, chitosan decreased the release of both trans- and cis-resveratrol respect to controls. No effect was shown on the accumulation of single resveratrol mono-glucoside isomers, but considering their total amount, normalized for the relative water control, it was possible to evidence an increase in both accumulation and release of those compounds, in chitosan-treated cells, throughout the culture period and particularly during the second week. Many of the analysed flavonoids and hydroxycinnamic acids were not present or detectable in trace amounts. Catechin, epicatechin and epigallocatechin-gallate (EGCG) were detectable both inside the cells and in the culture media, but chitosan did not affect their amounts. On the contrary, total anthocyanins have been stimulated by chitosan and their level, from day 4 to 14, was about 2-fold higher than in both controls, confirming macroscopic observations that treated suspensions showed an intense brown-red color, from day 3 onwards. These elicitation results suggest that chitosan selectively up-regulates specific biosynthetic pathways, without modifying the general accumulation pattern of other flavonoids. Proteins have been extracted from cells at day 4 of culture (corresponding to the production peak of trans-resveratrol) and separated by bidimensional electrophoresis. The 73 proteins that showed a consistently changed amount between untreated, chitosan and acetic acid (chitosan solvent) treated cells, have been identified by mass spectrometry. Chitosan induced an increase in stilbene synthase (STS, the resveratrol biosynthetic enzyme), chalcone-flavanone isomerase (CHI, that switches the pathway from chalcones to flavones and anthocyanins), pathogenesis-related proteins 10 (PRs10, a large family of defence proteins), and a decrease in many proteins belonging to primary metabolisms. A train of six distinct spots of STS encoded by the same gene and increased by chitosan, was detected on the 2-D gels, and related to the different phosphorylation degree of STS spots. Northern blot analyses have been performed on RNA extracted from cells treated with chitosan and relative controls, using probes for STS, PAL (phenylalanine ammonia lyase, the first enzyme of the biosynthetic pathway), CHS (chalcone synthase, that shares with STS the same precursors), CHI and PR-10. The up-regulation of PAL, CHS and CHI transcript expression levels correlated with the accumulation of anthocyanins. The strong increase of different molecular weight PR-10 mRNAs, correlated with the 11 PR-10 protein spots identified in proteomic analyses. The sudden decrease in trans-resveratrol endogenous accumulation after day 4 of culture, could be simply explained by the diminished resveratrol biosynthetic activity due to the lower amount of biosynthetic enzymes. This might be indirectly demonstrated by northern blot expression analyses, that showed lower levels of phenylalanine ammonia lyase (PAL) and stilbene synthase (STS) mRNAs starting from day 4. Other possible explanations could be a resveratrol oxidation process and/or the formation of other different mono-, di-glucosides and resveratrol oligomers such as viniferins. Immunolocalisation experiments performed on grape protoplasts and the subsequent analyses by confocal microscope, showed that STS, and therefore the resveratrol synthetic site, is mostly associated to intracellular membranes close to the cytosolic side of plasma membrane and in a smaller amount is localized in the cytosol. STS seemed not to be present inside vacuole and nucleus. There were no differences in the STS intracellular localisation between the different treatments. Since it was shown that stilbenes are largely released in the culture medium and that STS is a soluble protein, a possible interaction of STS with a plasma membrane transporter responsible for the extrusion of stilbenes in the culture medium, might be hypothesized. Proteomic analyses performed on subcellular fractions identified in the microsomial fraction 5 proteins taking part in channel complexes or associated with channels, that significantly changed their amount after chitosan treatment. In soluble and membrane fractions respectively 3 and 4 STS and 6 and 3 PR-10 have been identified. Proteomic results obtained from subcellular fractions substantially confirmed previous result obtained from total cell protein extracts and added more information about protein localisation and co-localisation. The interesting results obtained on Barbera cell cultures with the aim to increase polyphenol (especially stilbenes) production, have encouraged scale up tests in 1 litre bioreactors. The first trial fermentation was performed in parallel with a normal time-course in 20 mL flasks, showing that the scale-up (bigger volume and different conditions) process influenced in a very relevant way stilbenes production. In order to optimise culture parameters such as medium sucrose amount, fermentation length and inoculum cell concentration, few other fermentations were performed. Chitosan treatments were also performed. The modification of each parameter brought relevant variations in stilbenes and catechins levels, so that the production of a certain compound (or class of compounds) could be hypothetically promoted by modulating one or more culture parameters. For example the catechin yield could be improved by increasing sucrose content and the time of fermentation. The best results in stilbene yield were obtained in a 800 mL fermentation inoculated with 10.8 grams of cells and supplemented with chitosan. The culture was fed with MS medium added with 30 g/L sucrose, 25 μg/mL rifampicin and 50 μg/mL of chitosan, and was maintained at 24°C, stirred by marine impeller at 100 rpm and supplied of air at 0.16 L/min rate. Resveratroloside was the stilbene present in the larger amount, 3-5 times more than resveratrol. Because resveratrol glucosides are similarly active and more stable than free resveratrol, their production using a bioreactor could be a great advantage in an hypothetical industrial process. In my bioreactor tests, stilbenes were mainly released in the culture medium (60-80% of the total) and this fact could be another advantage for industrial applications, because it allows recovering the products directly from the culture medium without stopping the fermentation and/or killing the cells. In my best cultural conditions, it was possible to obtain 3.95 mg/L of stilbenes at day 4 (maximum resveratrol accumulation) and 5.13 mg/L at day 14 (maximum resveratroloside production). In conclusion, chitosan effect in inducing Vitis vinifera defense mechanisms can be related to its ability to increase the intracellular content of a large spectrum of antioxidants, and in particular of resveratrol, its derivates and anthocyanins. Its effect can be observed at transcriptional, proteomic (variation of soluble and membrane protein amounts) and metabolic (polyphenols production) level. The chitosan ability to elicit specific plant matabolisms can be useful to produce large quantities of antioxidant compounds from cell culture in bioreactor.

L'infiammazione intestinale nell'animale sperimentale come modello per lo sviluppo di nuovi farmaci: ruolo della via tachichininergica nelle malattie infiammatorie intestinali

Background: Several lines of evidence showed that inflammation is associated with changes in the expression of tachykinins both in human and animal models. Tachykinins, including substance P (SP), are small peptides expressed in the extrinsic primary afferent nerve fibres and enteric neurons of the gut: they exert their action through three distinct receptors, termed NK1, NK2 and NK3. SP modulates intestinal motility and enteric secretion, acting preferentially through the NK1 receptor. SP neural network and NK1 receptor expression are increased in patients with inflammatory bowel disease, and similar changes were observed in experimental models of inflammation. The 2,4 Dinitrobenzene Sulphonic Acid (DNBS) model of colitis is useful to study innate immunity, non-specific inflammation and wound healing; it has been suggested that the transmural inflammation seen in this model resembles that found in Crohn’s disease and can therefore be used to study what cells and mediators are involved in this type of inflammation. Aim: To test the possible protective effect of the NK1 receptor antagonist SSR140333 on: 1) acute model of intestinal inflammation; 2) reactivation of DNBS-induced colitis in rats. Methods: Acute colitis was induced in male SD rats by intrarectal administration of DNBS (15 mg/rat in 50% ethanol). Reactivation of colitis was induced by intrarectal injections of DNBS on day 28 (7.5 mg/rat in 35% ethanol). Animals were sacrificed on day 6 (acute colitis) and 29 (reactivation of colitis). SSR140333 (10 mg/kg) was administered orally starting from the day before the induction of colitis for 7 days (acute colitis) or seven days before the reactivation of colitis. Colonic damage was assessed by means of macroscopic and microscopic scores, myeloperoxidase activity (MPO) and TNF-α tissue levels. Enzyme immunoassay was used to measure colonic substance P levels. Statistical analysis was performed using analysis of variance (one-way or two-way, as appropriate) with the Bonferroni’s correction for multiple comparisons. Results: DNBS administration impaired body weight gain and markedly increased all inflammatory parameters (p<0.01). Treatment with SSR140333 10 mg/kg significantly counteracted the impairment in body weight gain, decreased macroscopic and histological scores and reduced colonic myeloperoxidase activity (p<0.01). Drug treatment counteracted TNF-α tissue levels and colonic SP concentrations (acute model). Similar results were obtained administering the NK1 receptor antagonist SSR140333 (3 and 10 mg/kg) for 5 days, starting the day after the induction of colitis. Intrarectal administration of DNBS four weeks after the first DNBS administration resulted in reactivation of colitis, with increases in macroscopic and histological damage scores and increase in MPO activity. Preventive treatment with SSR140333 10 mg/kg decreased macroscopic damage score, significantly reduced microscopic damage score but did not affect MPO activity. Conclusions: Treatment with SSR140333 significantly reduced intestinal damage in acute model of intestinal inflammation in rats. The NK1 receptor antagonist SSR140333 was also able to prevent relapse in experimental colitis. These results support the hypothesis of SP involvement in intestinal inflammation and indicate that NK receptor antagonists may have a therapeutic potential in inflammatory bowel disease.

Oberflächenmodifizierungen von Siliciumoxid und Poly(ethylen-stat-norbornen) durch Blockcopolymere und an Plasmaschichten gebundene Homopolymere

In der vorliegenden Arbeit erfolgten Oberflächenmodifizierungen durch Polymere nach zwei Ansätzen. Dies war zum einen ein Ansatz, bei dem die Oberflächen mit Diblockcopolymeren versehen wurden. Diese bestanden aus einem Ankerblock, der starke Wechselwirkungen mit der Oberfläche zeigt, und einem Bojenblock, der gezielte Eigenschaften trägt. Zum anderen erfolgten Modifizierungen durch auf Plasmaschichten verankerte Homopolymere. Beide Ansätze erfolgten auf zwei Substraten von unterschiedlichen Eigenschaften. Diese waren das Siliciumoxid, für das Modifizierungen durch radikalische in-situ Oberflächenpolymerisation, und das Poly(ethylen-stat-norbornen), für das Modifizierungen durch ex-situ dargestellte Polymere gewählt wurden. Beim ersten Ansatz zur Modifizierung der Siliciumoxidoberfläche ermöglichte ein adsorbierter Poly(e-caprolacton)-Makroinitiator die Oberflächenpolymerisation hin zu oberflächenverankertem Poly(e-caprolacton)-block-poly(alkyl(meth)acrylat). Beim zweiten Ansatz erfolgte die Abscheidung von plasmapolymerisiertem Allylamin, die Immobilisierung des Azoinitiators 4,4’-Azobis(4-cyanopentansäurechlorid) und die nachfolgende Oberflächenpolymerisation von Methylmethacrylat oder Styrol. Beim ersten Modifizierungsansatz der Poly(ethylen-stat-norbornen)-Oberfläche sollte diese mit thermisch interdiffundierten Poly(ethylen-alt-propylen)-block-poly(dimethylsiloxan) versehen werden. Trotz erfolgreicher Synthese wurde gezeigt, daß keine Interdiffusion stattfand. Im zweiten Modifizierungsansatz wurde die Oberfläche mit aus einem Hexamethyldisiloxan/Sauerstoff-Plasma abgeschiedenem reinem Siliciumoxid beschichtet, woran sich die Adsorption von Poly(dimethylsiloxan) anschloß. Damit konnten die hohen Haftreibungskräfte gegenüber Halogenbutylgummi erfolgreich beseitigt werden.

Die 18 F-Fluorierung verschiedener Aminosäuren als Tracer für die Tumor-Diagnostik mittels Positronen-Emissions-Tomographie

Die Zielsetzung dieser Arbeit war die Synthese und Markierung, sowie die in vitro- und in vivo-Evaluierung zweier markierter Aminosäure. Es wurden die PET-Tumor-Tracer C1-(2-[18F]Fluoreth- ylamino)-asparagin und S-2-Amino-4-[18F]fluor-butansäure synthetisiert. Die Markierung zum C1-(2-[18F]Fluorethylamino)-asparagin wurde mit 2-[18F]Fluorethylamin als Precursor durchgeführt. Ausgehend von N,N-Dibenzyl-(2-bromethyl)-amin wurde zunächst N,N-Dibenzyl-(2-[18F]fluorethyl)-amin in einer nukleophilen Substiution mit [18F]Fluorid in Acetonitril bei 80 °C mit einer Reaktionsdauer von 5 min dargestellt. Zur Abtrennung überschüssigen [18F]Fluorids wurde das Roh-Produkt auf einer Sep-Pak Plus Kartusche (C18) fixiert und mit Acetonitril eluiert. Die Abspaltung der Benzyl-Schutzgruppen erfolgte durch die Zugabe von Pd/C zu dem eluierten N,N-Dibenzyl-(2-[18F]fluorethyl)-amin und Behandelung der Lösung im leichten Wasserstoffstrom. Im finalen Aufreinigungsschritt wird der Katalysator Pd/C mittels eines Membranfilters abgetrennt. Das 2-[18F]Fluorethylamin wird im Sauren in das Amino-Salz überführt und im Vakuum vom Lösungsmittel befreit. Die Markierung zum C1-(2-[18F]Fluorethylamino)-asparagin wurde in DMF durchgeführt. Die höchsten Ausbeuten werden nach 4 min bei 60 °C erhalten. Die Abspaltung der Schutzgruppe erfolgt durch Trifluoressigsäure bei Raumtemperatur in 8 min. Die Aufreinigung des C1-(2-[18F]Fluorethylamino)-asparagin mittels HPLC und Festphasenextraktion liegt das Produkt in einer isotonischne isotonischen Kochsalzlösung vor. Die in vitro-Versuche wurden mit C1-(2-[18F]Fluorethylamino)-asparagin an 5 verschiedenen Zelllinen durchgeführt, 3 Plattenepitele und 2 Melanome. Hierbei konnte eine erhöhte Akkumulation von C1 -(2-[18F]Fluorethylamino)-asparagin beobachtet werden, die innerhalb von 20 min einen konstanten Wert erreicht. Ein Blockade-Experiment zeigte, dass sich die Aufnahme von C1 -(2-[18F]Fluorethylamino)-asparagin durch gesättinge Asparagin-Lösung bei den Plattenepitelen gar nicht und bei den Melanomen nur leicht vermindern ließ. Da die Aufnahme von C1-(2-[18F]Fluorethylamino)-asparagin in die Zellen höher war als bei FDG bei dem gleichen Versuchsaufbau, wurden in vivo-Versuche angesetzt. Die in vivo-Versuche an Sprague Dawley Ratten mit C1-(2-[18 F]Fluorethylamino)-asparagin zeigten keine messbare Anreicherung von C1-(2-[18F]Fluorethylamino)-asparagin in Tumoren. Fast die komplette Aktivität wurde in der Niere und Blase wiedergefunden. Die Synthese von S-2-Amino-4-[18F]fluor-butansäure wurde über stereodirigierende Auxilliare realisiert. Dazu wurden die geeignetsten Auxillare ausgewählt und auf ihre Eignung verglichen. Der Vergleich der stereodirigierenden Auxilare zeigte, dass das (1R,2R,5R)-2-Hydroxy-2,6,6-trimethyl- bicyclo[3.1.1]hept-3-ylidenamino)-essigsäure tert.-butylester (Laue-Auxillar) am geeignetesten ist. Die 18F-Markierung von S-2-Amino-4-[18F]fluor-butansäure wurde so optimiert, dass eine möglichst hohe stereochemische Reinheit des Produktes erzielt wird. Die optische Reinheit von S-2-Amino-4-[18 F]fluor-butansäure wurde mit > 93 % ee berechnet. Die Synthese des Markierungsvorläufers wurde ausgehend vom Laue-Auxilliar aufgebaut. Als Abgangsgruppe hat sich die Tosylgruppe besonders bewährt. Sie lässt sich unter besonders schonenden Bedingungen in den säurelabilen (1R,2R,5R)-4-Hydroxy-2-(2-hydroxy-2,6,6-trimethyl-bi- cyclo[3.1.1]hept-3-ylidenamino) butansäure tert.-butylester einführen. Bei der 18F-Markierung von S-2-Amino-4-[18F]fluor-butansäure mittels n.c.a. [18F]Fluorid hat sich die Wahl des Basensystems als besonders wichtig erwiesen. Die maximale Ausbeuten von 55% wurde mit Oxalat als Basensystem in Acetonitril bei 80 °C und einer Reaktionszeit von 15 min erzielen. Die Abspaltung der Schutzgruppen und die Abtrennung des Produktes wird in mehreren Schritten durchgeführt einschließlich einer HPLC-Abtrennung. Es wird nach 150 min Synthesedauer das gereinigte S-2-Amino-4-[18F]fluor-butansäure in isotonischer Kochsalzlösung mit einer Ausbeute von > 10 % RCA erhalten. Bei in vivo-Versuchen an Sprague Dawley Ratten reicherte sich der Hauptteil der Aktivität in der Niere an und nur weniger als ein halbes Prozent der applizierten Aktivität fand sich in den Tumoren wieder. Nach 10 min wurde ein maximaler Wert erreicht, der sich bis zum Ende der Messung nicht verändert. Das Verhältnis von Tumoraktivität zu unspezifisch-gebundener Aktivität betrug 2,2. Damit liegt das Verhältnis im Bereich der meisten klinisch eingesetzten PET-Tumor-Tracer wie dem des O-(2-[18F]Fluorethyl)-L-tyrosin mit 1,5.

Impact of folate absorption and transport for nutrition and drug targeting

In this thesis, interactions of folic acid with tea and tea components at the level of intestinal absorption have been investigated. Firstly, the interaction between folic acid and tea as well as tea catechins was studied in vitro, using Caco-2 cell monolayers and secondly, a clinical trial was designed and carried out. In addition, targeting of folic acid conjugated nanoparticles to FR expressing Caco-2 cells was studied in order to evaluate the principle of nutrient-receptor-coupled transport for drug targeting. In the first part of this work, it was shown that EGCG and ECG (gallated catechins) inhibit folic acid uptake (IC50 of 34.8 and 30.8 µmol/L) comparable to MTX (methotrexate) under these experimental conditions. Moreover, commercial green and black tea extracts inhibited folic acid uptake with IC50 values of approximately 7.5 and 3.6 mg/mL, respectively. These results clearly indicate an interaction between folic acid and green tea catechins at the level of intestinal uptake. The mechanism responsible for the inhibition process might be the inhibition of the influx transport routes for folates such as via RFC and/or PCFT. For understanding the in vivo relevance of this in vitro interaction, a phase one, open-labeled, randomized, cross-over clinical study in seven healthy volunteers was designed. For the 0.4 mg folic acid dose, the mean Cmax decreased by 39.2% and 38.6% and the mean AUC0 decreased by 26.6% and 17.9% by green tea and black tea, respectively. For the 5 mg folic acid dose, the mean Cmax decreased by 27.4% and mean AUC0 decreased by 39.9% when taken with green tea. The results of the clinical study confirm the interaction between tea and folic acid in vivo leading to lower bioavailabilities of folic acid. In the second part of the thesis, targeting studies using folic acid conjugated nanoparticles were conducted. Folic acid conjugated nanoparticles were shown to be internalized by the cell via FR (folate receptor) mediated endocytosis. DNA block copolymer micelles equipped with 2, 11 and 28 folic acid units respectively were applied on FR expressing Caco-2 cells. There was a direct proportion in the amount of internalized nanoparticle and the number of folic acid units on the periphery of the nanoparticle. To sum up, throughout this thesis, the importance of folic acid for nutrition and nutrient and drug related interactions of folic acid at intestinal level was shown. Furthermore, significance of FRs in targeting for cancer chemotherapy was demonstrated in in vitro cell culture experiments. Folic acid conjugated DNA block copolymer micelles were suggested as efficient nanoparticles for targeted drug delivery.

NMR studies on supramolecular aggregates in solution and the solid state

The aim of this work presented here is the characterization of structure and dynamics of different types of supramolecular systems by advanced NMR spectroscopy. One of the characteristic features of NMR spectroscopy is based on its high selectivity. Thus, it is desirable to exploit this technique for studying structure and dynamics of large supramolecular systems without isotopic enrichment. The observed resonance frequencies are not only isotope specific but also influenced by local fields, in particular by the distribution of electron density around the investigated nucleus. Barbituric acid are well known for forming strongly hydrogen-bonded complexes with variety of adenine derivatives. The prototropic tautomerism of this material facilitates an adjustment to complementary bases containing a DDA(A = hydrogen bond acceptor site, D = hydrogen bond donor site) or ADA sequences, thereby yielding strongly hydrogen-bonded complexes. In this contribution solid-state structures of the enolizable chromophor "1-n-butyl-5-(4-nitrophenyl)-barbituric acid" that features adjustable hydrogen-bonding properties and the molecular assemblies with three different strength of bases (Proton sponge, adenine mimetic 2,6-diaminopyridine (DAP) and 2,6-diacetamidopyridine (DAC)) are studied. Diffusion NMR spectroscopy gives information over such interactions and has become the method of choice for measuring the diffusion coefficient, thereby reflecting the effective size and shape of a molecular species. In this work the investigation of supramolecular aggregates in solution state by means of DOSY NMR techniques are performed. The underlying principles of DOSY NMR experiment are discussed briefly and more importantly two applications demonstrating the potential of this method are focused on. Calix[n]arenes have gained a rather prominent position, both as host materials and as platforms to design specific receptors. In this respect, several different capsular contents of tetra urea calix[4]arenes (benzene, benzene-d6, 1-fluorobenzene, 1-fluorobenzene-d5, 1,4-difluorobenzene, and cobaltocenium) are studied by solid state NMR spectroscopy. In the solid state, the study of the interaction between tetra urea calix[4]arenes and guest is simplified by the fact that the guests molecule remains complexed and positioned within the cavity, thus allowing a more direct investigation of the host-guest interactions.

L'uso dei farmaci antibatterici negli ospedali dell'Emilia-Romagna

Obiettivo Analisi di consumi e costi degli antibiotici sistemici negli ospedali dell’Emilia-Romagna dal 2004 al 2011, con attenzione alla variabilità interaziendale e al significato, in termini di resistenza batterica, dell’aumento di alcuni gruppi terapeutici; Sottoanalisi nei reparti pediatrici, individuando i gruppi terapeutici critici, e valutazione delle reazioni avverse pediatriche da antibiotici segnalate, per il periodo in esame. Metodi I dati di consumo e spesa degli antibiotici sistemici per il periodo 2004-2011 sono stati ottenuti dal database regionale AFO e le giornate di degenza per ogni reparto dal database regionale di dimissione ospedaliera SDO. Le segnalazioni di sospette reazioni avverse da antibiotici tra gennaio 2004 e dicembre 2011 sono state estratte dal database nazionale VigiSegn. Risultati Negli otto anni, il consumo di antibiotici negli ospedali dell’Emilia-Romagna è aumentato del 27% e la spesa del 3%. Il consumo è apparso nettamente superiore nei reparti chirurgici che medici. La prima classe per consumo e spesa sono le penicilline/inibitori delle beta lattamasi. Nei reparti pediatrici, sono stati utilizzati 65 principi attivi diversi e amoxicillina/acido clavulanico è stato il più usato (26% del totale del 2011). Tra gli antibiotici critici, le cefalosporine di terza generazione sono state le più consumate in tutti i reparti pediatrici nel 2011. Tra le molecole il cui uso ospedaliero è vincolato, spiccano il linezolid e la teicoplanina che, comunque, hanno inciso più di tutte nella spesa del 2011 (18% e 15%, rispettivamente). Per la farmacovigilanza, i bambini (3-13 anni) sono stati coinvolti in 23 casi, mentre gli infanti (≤2 anni) solo in 4. L’associazione amoxicillina/acido clavulanico è stata più frequentemente segnalata (n=7), e soltanto 2 casi erano gravi. Conclusioni I risultati mostrano un quadro critico sul massiccio uso delle cefalosporine di terza generazione e sull’incremento del linezolid, da approfondire se per inappropriatezza d’uso oppure per aumento delle resistenze batteriche.

On-surface chemical reactions on an insulating substrate

Diese Arbeit beschreibt zum ersten Mal die kovalente Verknüpfung organischer Moleküle auf einer Isolatoroberfläche, motiviert im Hinblick auf die Nutzung der Synthesemethode für die molekulare Elektronik und verwandte Anwendungen. Durch die Verwendung der Nichtkontakt-Rasterkraftmikroskopie und der Kelvinprobe-Mikroskopie bei Raumtemperatur wurden grundlegende molekulare Prozesse der Wechselwirkungen zwischen Molekülen und der Calcit(10.4) Oberfläche sowie die chemische Reaktivität der Moleküle auf der Oberfläche analysiert. Das Zusammenspiel zwischen intermolekularen und Molekül-Oberfläche Wechselwirkungen zeigt sich für Biphenyl-4,4'-dicarbonsäure (BPDCA) durch die Koexistenz zweier unterschiedlicher molekularer Strukturen, die einen Einblick in die treibenden Kräfte der molekularen Selbstorganisation bieten. Die sehr ausgeprägte Reihenstruktur basiert auf der optimalen geometrischen Struktur der BPDCA Moleküle zu den Abmessungen des Substrats, während die zweite Struktur durch Wasserstoffbrücken zwischen den Molekülen gekennzeichnet ist. Der Deprotonierungsvorgang von 2,5-Dihydroxybenzoesäure (DHBA)-Molekülen auf Calcit wird bei Zimmertemperatur gezeigt. Zwei Phasen werden beobachtet, die nach Aufbringen der Moleküle koexistieren. Mit der Zeit geht eine bulk-ähnliche Phase in eine stabile, dicht gepackte Phase über. Der Übergang wird durch Betrachtung des Protonierungszustands der Moleküle erklärt. Die bulk-ähnliche Phase benötigt Wasserstoffbrückbindungen zur Strukturbildung. Werden die Moleküle deprotoniert, so wird die resultierende dicht gepackte Phase durch die elektrostatische Wechselwirkung der deprotonierten Carboxylatgruppen mit den Oberflächen-Calciumkationen stabilisiert. 4-Iodbenzoesäure (IBA)-Moleküle bilden auf Calcit nur Inseln an Stufenkanten, was auf die schwache Molekül-Oberflächen-Wechselwirkung zurückzuführen ist. Für einen stärkeren Einfluss des Substrats durchlaufen die Moleküle einen kontrollierten Übergangsschritt vom protonierten zum deprotonierten Zustand. Im deprotonierten Zustand nehmen die Moleküle eine wohldefinierte Adsorptionsposition auf dem Substrat ein. Die deprotonierte Säuregruppe wird ausgenutzt, um die Desorption der halogensubstituierten Benzoesäure-Moleküle bei der thermischer Aktivierung für die Vernetzungsreaktion zu vermeiden. Darüber hinaus wird die Carboxylatgruppe als starker Elektronendonor verwendet um die Phenyl-Halogen-Bindung zu schwächen und somit die homolytische Spaltung dieser Bindung auch bei moderaten Temperaturen zu ermöglichen. Diesem Konzept folgend ist die erste erfolgreiche kovalente Verknüpfung von 2,5-Diiod-benzoesäure, 2,5-Dichlorbenzoesäure, 3,5-Diiod Salicylsäure und 4-Iod-benzoesäure zu durchkonjugierten molekularen Drähten, Zick-Zack-Strukturen sowie Dimere gezeigt durch Ausnutzen von unterschiedlichen Substitutionsposition sowie Ändern der Anzahl der substituierten Halogenatome. Aufbauend auf diesem Erfolg, wird eine zweistufige Vernetzungsreaktion vorgestellt. Zum Induzieren der ortsspezifischen und sequentiellen kovalenten Verknüpfung wird ein Ausgangsmolekül gewählt, das sowohl eine Bromphenyl als auch eine Chlorphenyl Gruppe mit unterschiedlichen Dissoziationsenergien für die homolytische Spaltung besitzt. Die Reaktionsstellen und sequentielle Reihenfolge für die Reaktion sind somit in der molekularen Struktur einkodiert und bisher unerreichte Reaktionspfade können mithilfe der kovalente Verknüpfung organischer Moleküle auf einer Isolatoroberfläche beschritten werden.

Unexpected sensitivity of sst2 antagonists to N-terminal radiometal modifications

Chelated somatostatin agonists have been shown to be sensitive to N-terminal radiometal modifications, with Ga-DOTA agonists having significantly higher binding affinity than their Lu-, In-, and Y-DOTA correlates. Recently, somatostatin antagonists have been successfully developed as alternative tracers to agonists. The aim of this study was to evaluate whether chelated somatostatin antagonists are also sensitive to radiometal modifications and how. We have synthesized 3 different somatostatin antagonists, DOTA-p-NO(2)-Phe-c[D-Cys-Tyr-D-Aph(Cbm)-Lys-Thr-Cys]-D-Tyr-NH(2), DOTA-Cpa-c[D-Cys-Aph(Hor)-D-Aph(Cbm)-Lys-Thr-Cys]-D-Tyr-NH(2) (DOTA-JR11), and DOTA-p-Cl-Phe-c[D-Cys-Tyr-D-Aph(Cbm)-Lys-Thr-Cys]-D-Tyr-NH(2), and added various radiometals including In(III), Y(III), Lu(III), Cu(II), and Ga(III). We also replaced DOTA with 1,4,7-triazacyclononane,1-glutaric acid-4,7-acetic acid (NODAGA) and added Ga(III). The binding affinity of somatostatin receptors 1 through 5 was evaluated in all cases. In all 3 resulting antagonists, the Ga-DOTA analogs were the lowest-affinity radioligands, with a somatostatin receptor 2 binding affinity up to 60 times lower than the respective Y-DOTA, Lu-DOTA, or In-DOTA compounds. Interestingly, however, substitution of DOTA by the NODAGA chelator was able to increase massively its binding affinity in contrast to the Ga-DOTA analog. The 3 NODAGA analogs are antagonists in functional tests. In vivo biodistribution studies comparing (68)Ga-DOTATATE agonist with (68)Ga-DOTA-JR11 and (68)Ga-NODAGA-JR11 showed not only that the JR11 antagonist radioligands were superior to the agonist ligands but also that (68)Ga-NODAGA-JR11 was the tracer of choice and preferable to (68)Ga-DOTA-JR11 in transplantable HEK293-hsst(2) tumors in mice. One may therefore generalize that somatostatin receptor 2 antagonists are sensitive to radiometal modifications and may preferably be coupled with a (68)Ga-NODAGA chelator-radiometal complex.

Microwave-Assisted Bond Forming Reactions

ABSTRACT FOR PART I: PHOSPHA-MICHAEL ADDITIONS TO ACTIVATED INTERNAL ALKENES: STERIC AND ELECTRONIC EFFECTS A method for the phospha-Michael addition of bis(4-methyl)phenyl phosphine oxide to activated internal alkenes has been developed. Michael acceptors including cinnamates, crotonates, chalcones, and internal alkenes containing multiple activating groups were all successfully utilized in this reaction. The reaction was fairly tolerant of electron-donating and electron-withdrawing substituents on the Michael acceptor, and moderate to excellent yields (49-96%) of the adducts were isolated. When steric bulk was increased by a second substituent on the -position of the Michael-acceptor the reaction was suppressed. This was usually overcome by adding a second activating substituent to the -position. ABSTRACT FOR PART II: MICROWAVE-ASSISTED ARYLGOLD BOND FORMATION A microwave-assisted method was developed for the formation of arylgold complexes containing (2-Biphenyl)di-tert-butylphosphine (JohnPhos) as the supporting phosphine ligand. Arylboronic acids with increasingly bulky aromatic groups were screened to determine the steric limitations of the reaction. Arylgold complexes (JohnPhos)Au(p-methoxyphenyl), (JohnPhos)Au(2,4,6-trimethylphenyl), and (JohnPhos)Au(4-bromo-10-anthracene) were all synthesized by microwave irradiation at 70ºC in the presence of Cs2CO3 in either THF or iPrOH. Reactions performed with arylboronic acids containing unhindered ortho positions were carried out in THF. Arylboronic acids with substituents on the ortho position required iPrOH as the reaction solvent. Arylboronic acids with extreme steric hindrance on the ortho position of the aryl substituent, 2,4,6-triisopropylpphenylboronic acid, were unreactive. It was determined that increasing the irradiation temperature increased the formation of side products, therefore to promote conversion to the arylgold complex the duration of the reaction time was increased while maintaining a temperature of 70ºC. Arylgold complexes (JohnPhos)Au(p-methoxyphenyl), (JohnPhos)Au(2,4,6-trimethylphenyl), and (JohnPhos)Au(4-bromo-10-anthracene) were synthesized with moderate yields (40-69%).

Metabolomic tissue signature in human non-alcoholic fatty liver disease identifies protective candidate metabolites

Background Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder in industrialized countries, yet its pathophysiology is incompletely understood. Small-molecule metabolite screens may offer new insights into disease mechanisms and reveal new treatment targets. Methods Discovery (N = 33) and replication (N = 66) of liver biopsies spanning the range from normal liver histology to non-alcoholic steatohepatitis (NASH) were ascertained ensuring rapid freezing under 30 s in patients. 252 metabolites were assessed using GC/MS. Replicated metabolites were evaluated in a murine high-fat diet model of NAFLD. Results In a two-stage metabolic screening, hydroquinone (HQ, pcombined = 3.0 × 10−4) and nicotinic acid (NA, pcombined = 3.9 × 10−9) were inversely correlated with histological NAFLD severity. A murine high-fat diet model of NAFLD demonstrated a protective effect of these two substances against NAFLD: Supplementation with 1% HQ reduced only liver steatosis, whereas 0.6% NA reduced both liver fat content and serum transaminase levels and induced a complex regulatory network of genes linked to NALFD pathogenesis in a global expression pathway analysis. Human nutritional intake of NA equivalent was also consistent with a protective effect of NA against NASH progression. Conclusion This first small-molecular screen of human liver tissue identified two replicated protective metabolites. Either the use of NA or targeting its regulatory pathways might be explored to treat or prevent human NAFLD.

Multiple inert gas elimination technique by micropore membrane inlet mass spectrometry--a comparison with reference gas chromatography.

The mismatching of alveolar ventilation and perfusion (VA/Q) is the major determinant of impaired gas exchange. The gold standard for measuring VA/Q distributions is based on measurements of the elimination and retention of infused inert gases. Conventional multiple inert gas elimination technique (MIGET) uses gas chromatography (GC) to measure the inert gas partial pressures, which requires tonometry of blood samples with a gas that can then be injected into the chromatograph. The method is laborious and requires meticulous care. A new technique based on micropore membrane inlet mass spectrometry (MMIMS) facilitates the handling of blood and gas samples and provides nearly real-time analysis. In this study we compared MIGET by GC and MMIMS in 10 piglets: 1) 3 with healthy lungs; 2) 4 with oleic acid injury; and 3) 3 with isolated left lower lobe ventilation. The different protocols ensured a large range of normal and abnormal VA/Q distributions. Eight inert gases (SF6, krypton, ethane, cyclopropane, desflurane, enflurane, diethyl ether, and acetone) were infused; six of these gases were measured with MMIMS, and six were measured with GC. We found close agreement of retention and excretion of the gases and the constructed VA/Q distributions between GC and MMIMS, and predicted PaO2 from both methods compared well with measured PaO2. VA/Q by GC produced more widely dispersed modes than MMIMS, explained in part by differences in the algorithms used to calculate VA/Q distributions. In conclusion, MMIMS enables faster measurement of VA/Q, is less demanding than GC, and produces comparable results.