Compositions for health products obtained by treatment of tomato with beta-cyclodextrin

The aim of this work was to produce lycopene-containing powders from tomato products by a solvent-free method making use of β-cyclodextrin (βCD). Powders were prepared by spray-drying a tomato concentrate (TC), one of the most bioavailable form of lycopene, after mechanical treatment with βCD in different weight ratios. The obtained product was centrifuged to eliminate partly food matrix and characterized for the amount of lycopene hydrodispersed/hydrosolubilized in the aqueous fraction. The chemical antioxidant activity of sera was evaluated too. Powders obtained by spray-drying sera exhibited good flow properties, a lycopene content between 0.4 and 1.09 mg/g and excellent water dispersability. The process developed, which makes use of βCD for the treatment of tomato products, turns to be of great interest to obtain a bulk material for nutraceuticals displaying superior biovailability of lycopene.     

Utilisation of 1,3-dialkylimidazolium-2-carboxylates as CO2-carriers in the presence of Na and K: application in the synthesis of carboxylates, monomethylcarbonate anions and halogen-free ionic liquids

1,3-Dialkylimidazolium-2-carboxylate compounds have recently been fully characterised. Here we describe the utilisation of 1,3-dimethyl (1a) and 1-butyl-3-methyl-imidazolium-2-carboxylate (1b) in a carboxylation reaction with transfer of the CO₂ moiety to benzoylacetone and methanol for the synthesis, in high yield, of benzoylacetate and monoalkylcarbonate anions, respectively. Conversely, when compounds 1a and b are reacted with carbonylic substrates lacking C-H active bonds, a product resulting from nucleophilic attack of the 1,3-dialkylimidazol-2-ylidene species on the carbonyl moiety is obtained. The reported reactions can find applications in organic synthesis and in the synthesis of halogen-free ionic liquids.     

Electrocatalytic Properties of a Novel Poly‐1‐Naphthylamine‐Modified Electrode Using Ascorbic Acid as Molecule Probe

A glassy carbon electrode was modified with an electropolymerized film of 1‐naphthylamine in aqueous solution. The electrocatalytic properties of this modified electrode (ME) were investigated using ascorbic acid (AA) as probe molecule. The electrochemical behavior of AA in buffer solution was examined by voltammetry and amperometry. The results showed that the ME exhibited good electrocatalytic activity towards the oxidation of AA, as a consequence, it can be used as amperometric sensor of this analyte in a flow injection system with good sensitivity. Calibration curves were linear over the concentration range 0.05–1.50 mM with a phosphate buffer solution pH 3 as the carrier, the detection limit was 1 ppm (S/N=3). The methods were applied to the determination of AA in beverages and pharmaceutical products. A good correlation with a reference method was attained.     

Chemometric studies in the Lagoon of Venice, Italy. Annual evolution of sulphur species and relationship to biogeochemical cycles in lagoon water

During the period March 1997-March 1998 dimethyl sulphide (DMS), dimethylsulphoniopropionate (DMSP) and carbon disulphide (CS2) were determined weekly in the water of the Lagoon of Venice, Italy (at three stations located in the Giudecca Canal, the San Secondo Canal and the Rio di San Nicolò). At the same time, the following hydrological and biological variables were also measured: tide height, temperature, transmittance, fluorescence, pH, salinity, chlorinity, sulphate, ammonia, nitrite, nitrate, phosphate, silicate, chlorophyll a, phaeopigments, phytoplankton (abundance and biomass). Principal component analysis (PCA), applied as a dimension reduction tool, made it possible to summarize multivariate information in a small number of components, which highlighted the relationships between the temporal evolutions of the sulphur compounds with hydrological and biological variables in the seasonal biogeochemical cycle of the lagoon. In particular the overall temporal cycle, which begins with the development of biological activity in late winter and spring, followed by the predominance of degradation processes during the late summer and the remineralization of nutrients in autumn, is clearly described in the plane of the first two principal components, together with the interrelationships between all the relevant variables.     

Fluid-like behavior of a one-dimensional granular gas

We study the properties of a one-dimensional (1D) granular gas consisting of N hard rods on a line of length L (with periodic boundary conditions). The particles collide inelastically and are fluidized by a heat bath at temperature Tb and viscosity gamma. The analysis is supported by molecular dynamics simulations. The average properties of the system are first discussed, focusing on the relations between granular temperature Tg=mv2, kinetic pressure, and density rho=N/L. Thereafter, we consider the fluctuations around the average behavior obtaining a slightly non-Gaussian behavior of the velocity distributions and a spatially correlated velocity field; the density field displays clustering: this is reflected in the structure factor which has a peak in the k approximately 0 region suggesting an analogy between inelastic hard core interactions and an effective attractive potential. Finally, we study the transport properties, showing the typical subdiffusive behavior of 1D stochastically driven systems, i.e., approximately Dt(1/2), where D for the inelastic fluid is larger than the elastic case. This is directly related to the peak of the structure factor at small wave vectors.     

Study of benznidazole–cyclodextrin inclusion complexes, cytotoxicity and trypanocidal activity

The current chemotherapy for Chagas disease is still based on benznidazole, which has low solubility, but complexation with cyclodextrins provides a way of increasing the solubility. The objective of this work was to characterize the inclusion complexes formed between benznidazole (BNZ) and randomly 2-methyled-β-cyclodextrin (RM-β-CD) in aqueous solution and study cytotoxicity and trypanocidal. BNZ:RM-β-CD solution complex systems were prepared and characterized using the phase solubility diagram, nuclear magnetic resonance and a photostability assays, also to investigate the in vitro trypanocidal activity with epimastigote forms of Trypanossoma cruzi and the study of cytotoxicity against mammal cells. The phase-solubility diagram displayed an A _L-type feature, providing evidence of the formation of soluble inclusion complexes. The continuous variation method showed the existence of a complex with 1:1 stoichiometry. Toxicity assays demonstrated that inclusion complexes were able to reduce the toxic effects caused by benznidazole alone and that this did not interfere with the trypanocidal activity of the benznidazole. The use of inclusion complexes benznidazole:cyclodextrin is thus a promising alternative for the development of a safe and stable liquid formulation and a new option for the treatment of Chagas disease.     

Chemical reducing pedoenvironment in a peatland influenced by hematitic phyllite lithology in the southern Espinhaço chain,Brazil

A peatland in Pinheiro, Diamantina City, Minas Gerais State - Brazil, was sampled at different depths of two profiles with diverse vegetation coverings (grassland field and bush) in order to collect materials that might reflect changes in the chemical states of iron over the peat formation coming from original minerals such as hematitic phyllite surrounding the boggy pedon. Samples collected were chemically, structurally and magnetically characterized. The results show that both series of peats are composed of organic matter and minerals such as quartz, kaolinite, gibbsite, rutile and muscovite. Deeper layers present only quartz. Mössbauer spectroscopy shows that iron is present in both electron states, Fe²⁺ and Fe³⁺, under both vegetations, each valence appearing in the spectra in the form of a discrete doublet. No hyperfine magnetic splitting was observed in any spectrum at room temperature. The Mössbauer subspectral area of Fe²⁺ tended to increase from the upper to deeper layers. Magnetic measurements reveal that the magnetic response of the surface samples is the highest, displaying a sharp decrease below 15 cm and that the magnetic signal is a superposition of (super)paramagnetic and ferrimagnetic contributions. Samples from the grassland field also show a diamagnetic component for the deeper layers.     

Laguncularia racemosa Phenolics Profiling by Three-Phase Solvent System Step-Gradient Using High-Performance Countercurrent Chromatography with Off-Line Electrospray Mass-Spectrometry Detection

The detailed metabolite profiling of Laguncularia racemosa was accomplished by high-performance countercurrent chromatography (HPCCC) using the three-phase system n-hexane–tert-butyl methyl ether–acetonitrile–water 2:3:3:2 (v/v/v/v) in step-gradient elution mode. The gradient elution was adjusted to the chemical complexity of the L. racemosa ethyl acetate partition and strongly improved the polarity range of chromatography. The three-phase solvent system was chosen for the gradient to avoid equilibrium problems when changing mobile phase compositions encountered between the gradient steps. The tentative recognition of metabolites including the identification of novel ones was possible due to the off-line injection of fractions to electrospray ionization mass spectrometry (ESI-MS/MS) in the sequence of recovery. The off-line hyphenation profiling experiment of HPCCC and ESI-MS projected the preparative elution by selected single ion traces in the negative ionization mode. Co-elution effects were monitored and MS/MS fragmentation data of more than 100 substances were used for structural characterization and identification. The metabolite profile in the L. racemosa extract comprised flavonoids, hydrolysable tannins, condensed tannins and low molecular weight polyphenols.     

Stripping Analysis of As(III) by Means of Screen‐Printed Electrodes Modified with Gold Nanoparticles and Carbon Black Nanocomposite

A novel sensor based on carbon black‐gold nanoparticle nanocomposite modified screen‐printed electrode (CB‐AuNPs/SPE) for the detection of As(III) has been developed. The sensor was prepared modifying the SPE with CB and AuNPs by a drop casting automatable deposition. The As(III) was detected by CB‐AuNPs/SPE using anodic stripping voltammetry, with a high sensitivity (673±6 µA µM^?1 cm^?2) and reaching a LOD of 0.4 ppb. Finally, CB‐AuNPs/SPE has been applied to As(III) trace analysis in drinking water, obtaining satisfactory recovery values (99±9 %).