Fanali C.,Biomedical University of Rome |
Dugo L.,Biomedical University of Rome |
Rocco A.,CNR Methodological Chemistry Institute
Journal of Chromatography A | Year: 2013
In this study, a nano-liquid chromatography based method for the simultaneous separation of 16 polyphenols employing UV-vis detection has been developed. A 100μm I.D. capillary column packed with C18 core-shell particles (2.6μm particle size, 100Å) for 10cm was employed. The separation of analytes was performed with a step gradient in less than 20min, using 0.5% formic acid aqueous solution and acetonitrile as eluents. The optimized analytical method was validated and the resulting RSD% for intra-day and inter-day repeatability, related to retention time, retention factor and peak area, were below 4.68 and 5.57%, respectively. LOD and LOQ values were as low as 0.78 and 3.12μg/mL, while linearity, assessed in the concentration range of interest for all analytes, gave R2≥0.990. The method was finally applied to the analysis of polyphenols extracted from a collected bee pollen. Nine polyphenols, namely o-, p-coumaric acid, ferulic acid, myricetin, cinnamic acid, quercetin, naringenin, hesperitin and kaempferol, were identified. All analytes, with the exception of p-coumaric acid and myricetin, which partially co-eluted with other pollen components, were also quantified in the sample. © 2013 Elsevier B.V.
Cevasco G.,University of Genoa |
Cevasco G.,CNR Methodological Chemistry Institute |
Chiappe C.,University of Pisa
Green Chemistry | Year: 2014
It is well known that ionic liquids (ILs) possess extraordinary characteristics, making them greener solvents with unique properties, which allow processes that would otherwise be difficult or impossible with common solvents to be carried out. In this review, we describe and discuss, in the light of possible future large scale applications, some fundamental studies showing the efficacy of ILs in several "hot" fields, from dissolution and transformation of biopolymers to extraction and capture of important inorganic components (metals) or pollutants (CO2). © the Partner Organisations 2014.
Mazzei P.,University of Naples Federico II |
Mazzei P.,CNR Methodological Chemistry Institute |
Piccolo A.,University of Naples Federico II
Food Chemistry | Year: 2012
The production of Mozzarella di Bufala Campana (MBC) is relevant for the agro-food economy of the Campania Region of Italy and the mark of Protected Designation of Origin (PDO) has been assigned to MBC in relation to its geographical origin. Advanced analytical methods must be then employed to assess authenticity, traceability, and quality of MBC. 1H HRMAS-NMR (High Resolution Magic Angle Spinning Nuclear Magnetic Resonance) spectroscopy was applied here to directly identify specific metabolites in MBC intact samples without time-consuming sample pre-treatments. Overcrowded conventional 1H HRMAS-NMR spectra were selectively simplified with two NMR pulse sequences: eCPMG and eDiff, by modulating spin-spin relaxation times and diffusion of MBC molecular components, respectively. Signal elaboration of edited spectra was combined with multivariate analyses to enable significant metabolic differentiation between MBC samples from two different production sites in Campania. Principal Components Analysis (PCA) for eCPMG spectra explained 97.54% of total variance between the two MBC groups for four metabolites (β-galactose, β-lactose, acetic acid, and glycerol). Less efficient was groups distinction by PCA for eDiff spectra, although differences in polyunsaturated acids, such as linoleic and linolenic acids, were highlighted. Similarly, Discriminant Analysis (DA) provided MBC group classification with 100% success in validation tests for eCPMG spectra, while DA prediction ability was reduced to 94.12% for eDiff spectra. Hierarchical Cluster Analysis (HCA) gave a totally correct classification between the two MBC groups only for eCPMG spectra. eCPMG spectra were also used to identify metabolites during MBC aging. As compared to fresh samples, 2 days old MBC samples showed increasing signals for isobutylic alcohol, lactic acid, and acetic acid. This work shows that 1H HRMAS-NMR spectroscopy can rapidly characterise the metabolic profile of intact MBC samples and statistically distinguish the geographical origin of buffalo milk mozzarella and its freshness. © 2011 Elsevier Ltd. All rights reserved.
Silvente S.,National Autonomous University of Mexico |
Sobolev A.P.,CNR Methodological Chemistry Institute |
Lara M.,National Autonomous University of Mexico
PLoS ONE | Year: 2012
Soybean (Glycine max L.) is an important source of protein for human and animal nutrition, as well as a major source of vegetable oil. The soybean crop requires adequate water all through its growth period to attain its yield potential, and the lack of soil moisture at critical stages of growth profoundly impacts the productivity. In this study, utilizing 1H NMR-based metabolite analysis combined with the physiological studies we assessed the effects of short-term water stress on overall growth, nitrogen fixation, ureide and proline dynamics, as well as metabolic changes in drought tolerant (NA5009RG) and sensitive (DM50048) genotypes of soybean in order to elucidate metabolite adjustments in relation to the physiological responses in the nitrogen-fixing plants towards water limitation. The results of our analysis demonstrated critical differences in physiological responses between these two genotypes, and identified the metabolic pathways that are affected by short-term water limitation in soybean plants. Metabolic changes in response to drought conditions highlighted pools of metabolites that play a role in the adjustment of metabolism and physiology of the soybean varieties to meet drought effects. © 2012 Silvente et al.
Dalla Cort A.,CNR Methodological Chemistry Institute |
De Bernardin P.,CNR Methodological Chemistry Institute |
Forte G.,CNR Methodological Chemistry Institute |
Yafteh Mihan F.,CNR Methodological Chemistry Institute
Chemical Society Reviews | Year: 2010
In this critical review the use of metal-salophen complexes as anion receptors is discussed with an emphasis on the supramolecular control of selectivity derived by the presence of additional interaction sites on the ligand skeleton. Some examples of application in sensing are also reported (112 references). © 2010 The Royal Society of Chemistry.
Salvio R.,CNR Methodological Chemistry Institute
Chemistry - A European Journal | Year: 2015
Examples of guanidinium-based artificial phosphodiesterases are illustrated in this review article. A wide set of collected catalytic systems are presented, from the early examples to the most recent developments of the use of this unit in the design of supramolecular catalysts. Special attention is dedicated to illustrate the operating catalytic mechanism and the role of guanidine/ium units in the catalysis. One or more of these units can act by themselves or in conjunction with other active units. The analogy with the mechanism of enzymatic systems is presented and discussed. In the last part of this overview, recent examples of guanidinophosphodiesterases based on nanostructured supports are reported, namely gold-monolayer-protected clusters and polymer brushes grafted to silica nanoparticles. The issue of the dependence of the catalytic performance on the preorganization of the spacer is tackled and discussed in terms of effective molarity, a parameter that can be taken as a quantitative measurement of this preorganization for both conventional molecular linker and nanosized supports. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Mannina L.,University of Rome La Sapienza |
Mannina L.,CNR Methodological Chemistry Institute |
Sobolev A.P.,CNR Methodological Chemistry Institute |
Viel S.,Aix - Marseille University
Progress in Nuclear Magnetic Resonance Spectroscopy | Year: 2012
The increasing interest towards application of NMR in food science is revealed both by the constantly increasing number of papers and reviews on this topic and by international and national congresses dedicated to this field. The strength of the H metabolomic approach is the capacity to look at all the components of a mixture at once allowing a metabolite quantitative analysis and thus generating many data from which it is necessary to extract the required information. The application of chemometric methods can reduce the dimension of the NMR data identifying possible patterns among samples. Relative deuterium concentration and specific deuterium-site locations have also been determined in other alcoholic beverages, fruit juices, aromas and perfumes, fats and oils, milk, and drug. Metabolic profiling requires identification and quantification of a number of selected metabolites, belonging to various classes of compounds, in a given sample often without a separation procedure.
Ciaccia M.,CNR Methodological Chemistry Institute |
Cacciapaglia R.,CNR Methodological Chemistry Institute |
Mencarelli P.,CNR Methodological Chemistry Institute |
Mandolini L.,CNR Methodological Chemistry Institute |
Di Stefano S.,CNR Methodological Chemistry Institute
Chemical Science | Year: 2013
Amine-imine exchange reactions of sterically unhindered reactants were found to be surprisingly fast at room temperature in a variety of nonaqueous solvents in the absence of proton and metal catalysts. The reaction mechanism suggested by ab initio calculations in the gas phase involves nucleophilic addition to the CN bond in concert with proton transfer from the amine NH bond to the imine nitrogen via a highly imbalanced transition state. These very fast transimination reactions were utilized in the catalysis of imine metathesis. Imine metathesis, usually carried out in organic solvents at high temperature in the presence of metal catalysts, occurs smoothly at room temperature in the presence of primary amines under nonacidic conditions as a result of coupled transimination processes. Kinetic data fully consistent with the proposed reaction mechanism were obtained. © 2013 The Royal Society of Chemistry.
Gentili P.,CNR Methodological Chemistry Institute |
Pedetti S.,CNR Methodological Chemistry Institute
Chemical Communications | Year: 2012
A novel α-oximation reaction of unactivated aldehydes has been achieved in excellent yields by reaction with NaNO 2-FeCl 3 couple and in the presence of pyrrolidine as organocatalyst. © 2012 The Royal Society of Chemistry.
Salvio R.,CNR Methodological Chemistry Institute |
Cincotti A.,CNR Methodological Chemistry Institute
RSC Advances | Year: 2014
Gold nanoparticles passivated with a long chain alkanethiol decorated with a phenoxyguanidine moiety were prepared and investigated as catalysts in the cleavage of the RNA model compound HPNP and diribonucleoside monophosphates. The catalytic efficiency and the high effective molarity value of the Au monolayer protected colloids points to a high level of cooperation between the catalytic groups. © 2014 the Partner Organisations.