Obesity is a complex multifactorial disease involving genetic and environmental factors and influencing several different metabolic pathways. In this regard, metabonomics, that is the study of complex metabolite profiles in biological samples, may provide a systems approach to understand the global metabolic regulation of the organism in relation to this peculiar pathology. In this pilot study, we have applied a nuclear magnetic resonance (NMR)-based metabolomic approach on urinary samples of morbidly obese subjects. Urine samples of 15 morbidly obese insulin-resistant (body mass index440; homeostasis assessment model of insulin resistance43) male patients and 10 age-matched controls were collected, frozen and analyzed by high-resolution 1 H-NMR spectroscopy combined with partial least squares-discriminant analysis. Furthermore, two obese patients who underwent bariatric surgery (biliopancreatic diversion and gastric bypass, respectively) were monitored during the first 3 months after surgery and their urinary metabolic profiles were characterized. NMR-based metabolomic analysis allowed us to identify an obesity-associated metabolic phenotype (metabotype) that differs from that of lean controls. Gut flora-derived metabolites such as hippuric acid, trigonelline, 2-hydroxyisobutyrate and xanthine contributed most to the classification model and were responsible for the discrimination. These preliminary results confirmed that in humans the gut microflora metabolism is strongly linked to the obesity phenotype. Moreover, the typical obese metabotype is lost after weight loss induced by bariatric surgery.

Breast milk is a complex fluid evolutionarily adapted to satisfy the nutritional requirements of growing infants. In addition, milk biochemical and immunological components protect newborns against infective agents in the new environment. Human milk oligosaccharides, the third most abundant component of breast milk, are believed to modulate the microbiota composition, thus influencing a wide range of physiological processes of the infant. Human milk also contains a number of other bioactive compounds, the functional role of which has not yet been clearly elucidated. In this scenario, NMR-based metabolic profiling can provide a rapid characterisation of breast milk composition, thus allowing a better understanding of its nutritional properties.

No abstract

No abstract

No abstract

The metabolite profile of aqueous extracts of two peach varieties, Percoca Romagnola 7 and Flaminia, with different susceptibilities to Ceratitis capitata attack was investigated by means of 1D and 2D high-field NMR spectroscopy. Water-soluble metabolites belonging to different classes such as organic acids (citric, fumaric, malic, quinic, shikimic, and succinic acids), sugars (fucose, fructose, fructose-6-phosphate, glucose, glucose-6-phosphate, rhamnose, sucrose, and xylose), amino acids (alanine, asparagine, isoleucine, threonine, and valine) and other metabolites such as myo-inositol, choline, trigonelline, catechin, chlorogenic and neochlorogenic acids, orthophosphate, and α-l-glycerophosphorylcholine were identified. The metabolite profile together with a suitable statistical analysis was used to make a comparison between the two varieties. The levels of glucose, xylose, myo-inositol, choline, isoleucine, and valine were found to be higher in Flaminia than in Percoca Romagnola 7 samples, whereas the levels of fumaric acid, alanine, quinic acid, sucrose, fucose, and chlorogenic and neochlorogenic acid were found to be higher in Percoca Romagnola 7 than in Flaminia samples.

The solubilization of bilirubin-IXalpha (BR) in submicellar and micellar aqueous solutions of sodium deoxycholate (NaDC) was investigated by circular dichroism (CD) and nuclear magnetic resonance (NMR) measurements. BR exhibits a bisignate CD Cotton effect in micellar solutions of NaDC at pH about 8, thus indicating that NaDC interacts preferentially with the BR molecule having left-handed chirality. However, the CD spectrum changes as a function of pH and BR concentration. Moreover, the spectrum becomes inverted at NaDC concentration below the critical micellar concentration. Potential energy calculations accomplished for the system formed by one-deoxycholate anion (DC-) and the left- or right-handed BR molecule (LBR or RBR, respectively) show that the DC--RBR complex is more stable than the DC--LBR one and are in agreement with the CD results. Interaction models are proposed and checked by NMR measurements. The influence of pH and BR concentration on the CD spectra, NaDC being in submicellar and micellar state, is discussed

No abstract