Stefania Cesa

Evaluation of different extraction methods from pomegranate whole fruit or peels and the antioxidant and antiproliferative activity of the polyphenolic fraction

Pomegranate is a functional food of great interest, due to its multiple beneficial effects on human health. This fruit is rich in anthocyanins and ellagitannins, which exert a protective role towards degenerative diseases. The aim of the present work was to optimize the extraction procedure, from different parts of the fruit, to obtain extracts enriched in selected polyphenols while retaining biological activity. Whole fruits or peels of pomegranate cultivars, with different geographic origin, were subjected to several extraction methods. The obtained extracts were analyzed for polyphenolic content, evaluated for antioxidant capacity and tested for antiproliferative activity on human bladder cancer T24 cells. Two different extraction procedures, employing ethyl acetate as a solvent, were useful in obtaining extracts enriched in ellagic acid and/or punicalagins. Antioxidative and antiproliferative assays demonstrated that the antioxidant capability is directly related to the phenolic content, whereas the antiproliferative activity is to be mainly attributed to ellagic acid.

The system as mild and safe carboxylating reagent synthesis of organic carbonates

Abstract The system, originating from electrochemical one-electron reduction of dioxygen in dipolar aprotic solvents and in the presence of CO 2 , converts primary and secondary alcohols bearing a leaving group at α orβ position into the corresponding cyclic carbonates in high to excellent yields. Unsubstituted alcohols are also converted, but in unsatisfactory yields, into the corresponding alkyl ethyl carbonates after completion of the reaction by addition of Etl. Tertiary alcohols and phenols are stable to the reagent, thus allowing selective carboxylation of polyhydroxy derivatives. CH-acid containing compounds underfo diferent reactions, if any, with the reagent but in the cases under study the formation of carboxylation products has never been observed.

Influence of the formulation components on the properties of the system SLN-dextran hydrogel for the modified release of drugs

A system composed by solid lipid nanoparticles (SLN) entrapped into a chemical hydrogel of dextran was recently proposed for the controlled release of lipophilic drugs in oral formulations. This study reports now an extension of such study focused on the investigation of how the nature and the amount of the formulation components are able to modify the properties of the system. In particular the concentration of the two surfactants used for the nanosuspension stabilization, the nature of the lipid phase used for the nanoparticles preparation, as well as the concentration and the derivatization degree of the polymer employed for the gel preparation were investigated. The effects of these variables on the physicochemical properties of the nanoparticles and/or on the release profiles of the model drug (S)-(+)-2-(4-isobutylphenyl)-propionic acid (ibuprofen) were reported and discussed. Rheological experiments on samples of SLN, dextran hydrogel, and SLN-dextran hydrogel were also performed.

Electrogenerated Base-Promoted Synthesis of Organic Carbonates from Alcohols and Carbon Dioxide

Electrogenerated bases promote the reaction between primary alcohols and carbon dioxide to give organic carbonates in excellent yields. Secondary alcohols are converted in moderate yields, whereas tertiary alcohols and phenols are unreactive. 1,2-Diols give a mixture of both cyclic and linear di- and monocarbonates. These latter are intermediates in the reaction pathway leading to the cyclic derivatives.

Evaluation of processing effects on anthocyanin content and colour modifications of blueberry (Vaccinium spp.) extracts: Comparison between HPLC-DAD and CIELAB analyses

Colour is the first organoleptic property that consumers appreciate of a foodstuff. In blueberry (Vaccinium spp.) fruits, the anthocyanins are the principal pigments determining the colour as well as many of the beneficial effects attributed to this functional food. Commercial blueberry-derived products represent important sources of these healthy molecules all year round. In this study, blueberries were produced into purees comparing two homogenization methods and further heated following different thermal treatments. All the supernatants of the homogenates were monitored for pH. Then, the hydroalcoholic extracts of the same samples were characterized by CIELAB and HPLC-DAD analyses. These analytical techniques provide complementary information on fruit pigments content as a whole and on quali-quantitative profile of the single bioactive colorants. These data could be very interesting to know the best manufacturing procedure to prepare blueberry-derived products, well accepted by the consumers, while maintaining their healthy properties unaltered.

Electrochemical studies on haloamides. Part XII. Electrosynthesis of oxazolidine-2,4-diones

Abstract Electrogenerated bases promote the carboxylation of NH-protic carboxamides bearing a leaving group at the position 2 to give oxazolidine-2,4-diones. The process is believed to involve acid-base reaction with the substrate, carboxylation of its conjugate base to the corresponding carbamate and ring-closure following intramolecular S N 2 reaction. A variety of oxazolidine-2,4-diones, including clinically used trimethadione® and malidone®, have been prepared in high to excellent yield, which established the scope and generality of this new ring-forming process.

Essential oil extraction, chemical analysis and anti-Candida activity of Foeniculum vulgare Miller – new approaches

Abstract A comprehensive study on essential oil samples of Foeniculum vulgare Miller from Tarquinia (Italy) is reported. A 24-h systematic steam distillation was performed on different harvested samples applying different extraction times. The GC-MS analysis of the residue outcome showed o-cymene, α-phellandrene, α-pinene and estragole as the major constituents. The predominance and continued presence of o-cymene makes this fennel oil a rather unique chemotype. An evident correlation between the antifungal activity and phenological stage is demonstrated. The most active fractions were particularly rich in estragole, as well as a significant amount of fenchone that possibly exerts some additive effect in the expression of overall antifungal potency. Pre-fruiting material produced oil particularly rich in o-cymene. With reference to the duration of the extraction, the maximum amount of oil was released within the first 3 h, whereas the reproductive phase material needed at least 6 h for the extraction.

Graminex Pollen: Phenolic Pattern, Colorimetric Analysis and Protective Effects in Immortalized Prostate Cells (PC3) and Rat Prostate Challenged with LPS

Prostatitis, a general term describing prostate inflammation, is a common disease that could be sustained by bacterial or non-bacterial infectious agents. The efficacy of herbal extracts with antioxidant and anti-inflammatory effects for blunting the burden of inflammation and oxidative stress, with possible improvements in clinical symptoms, is under investigation. Pollen extracts have been previously reported as promising agents in managing clinical symptoms related to prostatitis. The aim of the present work was to evaluate the protective effects of Graminex pollen (GraminexTM, Deshler, OH, USA), a commercially available product based on standardized pollen extracts, in rat prostate specimens, ex vivo. In this context, we studied the putative mechanism of action of pollen on multiple inflammatory pathways, including the reduction of prostaglandin E2 (PGE2), nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), and malondialdehyde (MDA), whose activities were significantly increased by inflammatory stimuli. We characterized by means of chromatographic and colorimetric studies the composition of Graminex pollen to better correlate the activity of pollen on immortalized prostate cells (PC3), and in rat prostate specimens challenged with Escherichia coli lipopolysaccharide (LPS). We found that Graminex pollen was able to reduce radical oxygen species (ROS) production by PC3 cells and MDA, NFκB mRNA, and PGE2 levels, in rat prostate specimens. According to our experimental evidence, Graminex pollen appears to be a promising natural product for the management of the inflammatory components in the prostate.

Solid Lipid Nanoparticles as Effective Reservoir Systems for Long-Term Preservation of Multidose Formulations

Cosmetic multidose preparations, as well as pharmaceutical ones, are at risk of contamination by microorganisms, due to their high water content. Besides the risk of contamination during manufacturing, multidose cosmetic preparations may be contaminated by consumers during their use. In this paper, the results of the utilization of nanoparticles as reservoir systems of parabens, the most used class of preservatives, were reported. Two different systems, solid lipid nanoparticles (SLN) made of pure precirol and nanostructured lipid carriers (NLC) made of precirol and almond oil, containing three parabens as single molecules or as a mixture, were prepared and tested. All the systems were characterized for size, polydispersion index, zeta potential and encapsulation efficiency. Release experiments, carried out in steady state and sink conditions, allowed to evidence that both SLN and NLC were able to act as reservoir systems. The antimicrobial activity of the systems was tested against Candida albicans ATCC 10231 with repeat insult tests. The results of the release experiments and the antimicrobial tests showed very low water concentration of parabens still maintaining their antimicrobial activity.

TETRAETHYLAMMONIUM HYDROGEN CARBONATE IN ORGANIC SYNTHESIS : SYNTHESIS OF OXAZOLIDINE-2,4-DIONES

Abstract Oxazolidine-2,4-diones were synthesised by tetraethylammonium hydrogen carbonate (TEAHC) promoted carboxylation of secondary carboxamides bearing a leaving group at the α-position. Several oxazolidine-2,4-diones, including clinically used malidone®, have been prepared in moderate to excellent yields as a results of a formal proton extraction-carboxylation-intramolecular SN2 one-pot sequence.