Flaminia Cesare Marincola

A metabolomic study of preterm human and formula milk by high resolution NMR and GC/MS analysis: preliminary results

Objective: The aim of the present study was to investigate the metabolic profile of preterm human breast milk (HBM) by using a metabolomic approach. Methods: NMR spectroscopy and GC/MS were used to analyze the water-soluble and lipid fractions extracted from milk samples obtained from mothers giving birth at 26–36 weeks of gestation. For the sake of comparison, preterm formula milk was also studied. Results: The multivariate statistical analysis of the data evidenced biochemical variability both between preterm HBM and commercial milk and within the group of HBM samples. Conclusions: The preliminary results of this study suggest that metabolomics may provide a promising tool to study aspects related to the nutrition and health of preterm infant.

Bisphosphonate chelating agents: complexation of Fe(III) and Al(III) by 1-phenyl-1-hydroxymethylene bisphosphonate and its analogues

Abstract Bisphosphonate ligands were found to be very efficient chelating agents for both Al(III) and Fe(III) ions. Potentiometric and spectroscopic data allow evaluation of the coordination equilibria in the solutions containing 1-phenyl-1-hydroxymethylene bisphosphonate and its three analogues with Al(III) and Fe(III) ions. At pH below 4 the bis-complexes are formed, while above pH 4 the major species are equimolar, monomeric for Al(III) or dimeric for Fe(III) complexes. The large steric hindrance and high electric charge are the major factors influencing the complex stoichiometry. The formation of the dimeric Fe(III) with μ-oxo or μ-hydroxo bridges were supported by measurements of the magnetic moments using Evans’ method. The stabilities of the complexes formed are higher than those found for deferiprone, L1, used in clinics as a chelating agent.

A NMR metabolomics study of the ripening process of the Fiore Sardo cheese produced with autochthonous adjunct cultures

Fiore Sardo (FS) is a traditional Italian raw ewes milk cheese carrying a Protected Designation of Origin (PDO). This study investigated the kinetics of FS cheese ripening by physicochemical parameters, microbial counting, and NMR metabolomics using aqueous extracts. Four Fiore Sardo cheeses, manufactured from milk with deliberately added autochthonous lactic acid bacteria (LAB) or commercial starters were studied during a period of 90days of ripening. Major differences in the metabolic profiles were observed amongst the samples as a function of the adjunct culture utilised. (1)H NMR metabolomics in combination with multivariate data analysis was able to classify cheese samples on the basis of their maturation age and the type of added cultures. These findings lay the metabolic basis for the authentication of Fiore Sardo cheese produced in compliance with PDO specifications which allow the use of only native LAB cultures.

An energy dispersive x-ray scattering and molecular dynamics study of liquid dimethyl carbonate

In this work, we report on the first x-ray diffraction study on liquid dimethyl carbonate. Diffraction spectra were collected with an energy-dispersive instrument, whose wide Q-range allows the structure determination of weakly ordered systems (such as liquids). The structural correlation in this liquid ranges up to about 20 A. The observed patterns are interpreted with a structural model derived from classical molecular dynamics simulations. The simulations were run using OPLS force field, only slightly modified to restrain bond distances to the experimental values. The model structure function and radial distribution functions, averaged among the productive trajectory frames, are in very good agreement with the corresponding experimental ones. Molecular dynamics results show that the deviations from C(2v) cis-cis structure, predicted by ab initio calculations and observed by electron diffraction in the gas phase, are small. By analyzing the intra- and intermolecular pair distribution functions, it was possible to assign the peaks of the experimental radial distribution function to specific structural correlations, and to compute the different average intermolecular coordination numbers. The intermolecular methyl-carbonyl oxygen distance is thoroughly discussed to assess the presence of weak C-H...O hydrogen bonds.

NMR Investigation of Imidazolium-Based Ionic Liquids and Their Aqueous Mixtures

(1)H and (13)C NMR spectroscopy is employed to investigate the interaction of water with two imidazolium-based ionic liquids (ILs), 1-hexyl-3-methylimidazolium bromide ([C(6)mim]Br) and 1-octyl-3-methylimidazolium bromide ([C(8)mim]Br), at IL concentrations well above the critical aggregation concentration (CAC). The results are compared with those of the neat samples. To this aim, a detailed analysis of the changes in the (1)H chemical shifts, (13)C relaxation parameters, and 2D ROESY data due to the presence of water is performed. The results for both neat ILs are consistent with a packed structure where head-to-head, head-to-tail, and tail-to-tail contacts occur and where the site of maximal mobility restriction is at the polar head. At the lowest investigated water content, the presence of water influences mainly the environment around the IL polar head, slowing down the motional dynamics of the aromatic ring with respect to the alkyl chain. At higher water contents this difference diminishes, the motional freedom of the whole molecule increasing. The presence of ROESY cross-peaks between protons in the polar and apolar IL regions, as well as between protons in non-neighboring alkyl groups, at all investigated water contents suggests that the alkyl tails are not fully segregated in hydrophobic domains, as expected for micelle-like structures.

Clinical impact of human breast milk metabolomics.

Metabolomics is a research field concerned with the analysis of metabolome, the complete set of metabolites in a given cell, tissue, or biological sample. Being able to provide a molecular snapshot of biological systems, metabolomics has emerged as a functional methodology in a wide range of research areas such as toxicology, pharmacology, food technology, nutrition, microbial biotechnology, systems biology, and plant biotechnology. In this review, we emphasize the applications of metabolomics in investigating the human breast milk (HBM) metabolome. HBM is the recommended source of nutrition for infants since it contains the optimal balance of nutrients for developing babies, and it provides a range of benefits for growth, immunity, and development. The molecular mechanisms beyond the inter- and intra-variability of HBM that make its composition unique are yet to be well-characterized. Although still in its infancy, the study of HBM metabolome has already proven itself to be of great value in providing insights into this biochemical variability in relation to mother phenotype, diet, disease, and lifestyle. The results of these investigations lay the foundation for further developments useful to identify normal and aberrant biochemical changes as well as to develop strategies to promote healthy infant feeding practices.

Metabolomics and the great obstetrical syndromes - GDM, PET, and IUGR

Gestational diabetes mellitus, intrauterine growth restriction, and preeclamptic toxemia are common pregnancy complications that can have detrimental effects on morbidity and mortality of the mother and fetus as well as long-term health outcomes. Although they are distinct conditions, they may occur together and are often considered together as they share a common etiology of inadequate placental perfusion. The discovery and study of preventative treatments is hampered by a lack of effective screening tools to accurately identify women at the highest risk of disease. Metabolomics, an omic science, is the global quantitative assessment of endogenous metabolites within a biological system. It has proven to be a rapid approach in the identification of biomarkers predictive of the outcome of a pathological condition and the individuals response to a pharmacological treatment. We review the current and potential applications of metabolomics in maternal-fetal medicine, focusing on its use as a biomarker for great obstetrical syndromes diagnosis.

Conformational isomerisms and nano-aggregation in substituted alkylammonium nitrates ionic liquids: An x-ray and computational study of 2-methoxyethylammonium nitrate

In this study, we discuss, using molecular dynamics simulations and energy-dispersive x-ray diffraction data, how a conformational isomerism can dramatically alter the nanosegregation phenomena that take place in a prototypical ionic liquid. The diffraction patterns of liquid 2-methoxyethylammonium nitrate are compared with the results from molecular dynamics simulations. The simulations conditions and force field parameters have been varied producing different charge models and different populations of conformers of the cation. We show that, while the short range structure is relatively unchanged in the models, the long range aggregation phenomena deemed responsible for the appearance of low Q peaks in the X-ray patterns strongly depend on the choice of the charge model. In the title compound, the best agreement with the experiment, where no low Q peaks appear, occurs if the point charges are calculated using the gauche conformation of the cation, which is characterized by an intramolecular hydrogen bond between ammonium and ether groups.

Analysing the effects of frozen storage and processing on the metabolite profile of raw mullet roes using 1H NMR spectroscopy

(1)H NMR spectroscopy was used to investigate changes in the low molecular weight metabolic profile of raw mullet (Mugil spp.) roes during frozen storage and upon processing. NMR data were analysed by Principal Component Analyses (PCA). In the model constructed using frozen roes, no statistical significant metabolic modifications were observed in the first six months of storage, while choline derivatives, dimethylamine, lactate, and most of the free amino acids were identified as changing with statistical significance (p<0.05) in response to frozen storage time of twelve months. The PCA model comparing the metabolic profiles of roes before and after processing showed that the major modifications occurring upon manufacturing were the increase of the choline derivative compounds, uracil, and free amino acids, and a large decrease of taurine, glucose, lactate, and creatine/phosphocreatine. All of the above mentioned modifications reflect the occurrence of chemical/biochemical reactions arising from degradation processes such as lipolysis and proteolysis.

Investigation of the 1H-NMR based urine metabolomic profiles of IUGR, LGA and AGA newborns on the first day of life

Abstract 1H-NMR spectroscopy coupled with multivariate statistical analysis was used for the first time to compare the urinary NMR metabolic profiles of neonates with intrauterine growth retardation (IUGR) and large for gestational age (LGA). For the sake of comparison, infants who were adequate for gestational age (AGA) were also analyzed. Pattern recognition methods, including Principal Component Analyses (PCA), Partial Least Squares Discriminant Analysis (PLS-DA) and Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA), were used to analyze NMR data. Clear differences among the metabolic profiles of AGA, IUGR and LGA were observed. The main metabolites responsible for these differentiations were identified as myo-inositol, creatinine, creatine, citrate, urea and glycine. In particular, among these, myo-inositol may be a potential biomarker of an altered glucose metabolism during fetal development both in IUGR and LGA. This study highlights the applicability of NMR-based metabolomics for improving the understanding of the relations among nutrition, integrated metabolism and health in neonatology.