3,5-diiodo-L-thyronine (3,5-T2) is an endogenous derivative of thyroid hormone with potential metabolic effects. It has been detected in human blood by immunological methods, but a reliable assay based on mass spectrometry (MS), which is now regarded as the gold standard in clinical chemistry, is not available yet. Therefore, we aimed at developing a novel ad-hoc optimized method to quantitate 3,5-T2 and its isomers by MS in human serum. Serum samples were obtained from 28 healthy subjects. Two ml of serum were deproteinized with acetonitrile and then subjected to an optimized solid phase extraction-based procedure. To lower background noise, the samples were furtherly cleaned by hexane washing and acetonitrile precipitation of residual proteins. 3,5-T2 and its isomers 3,3′-T2 and 3′,5′-T2 were then analyzed by HPLC coupled to tandem MS. Accuracy and precision for T2 assay were 88–104% and 95–97%, respectively. Recovery and matrix effect averaged 78% and +8%, respectively. 3,5-T2 was detected in all samples and its concentration averaged (mean ± SEM) 41 ± 5 pg/ml, i.e., 78 ± 9 pmol/l. In the same samples the concentration of 3,3′-T2 averaged 133±15 pg/ml, i.e., 253±29 pmol/l, while 3′,5′-T2 was not detected. 3,5-T2 concentration was significantly related to 3,3′-T2 concentration ( r = 0.540, P < 0.01), while no significant correlation was observed with either T3 or T4 in a subset of patients in which these hormones were assayed. In conclusion, our method is able to quantify 3,5-T2 and 3,3′-T2 in human serum. Their concentrations lie in the subnanomolar range, and a significant correlation was detected between these two metabolites in healthy individuals.
Several procedures of extraction with solvents for the simultaneous determination of vitamin C and some vitamins belonging to the B group (thiamine, riboflavine, nicotinic acid and nicotinamide) in multivitamin preparations and in artichokes (Cynara cardunculus subsp. scolymus [L.] Hegi) were developed. Different experimental conditions were used, in terms of heat treatment, composition and pH of the extraction mixture, with particular attention to high-temperature steps; purification of the extracts with solid phase extraction and stabilisation through lyophilisation were discussed. Analyses of the extracts were conducted by capillary electrophoresis in micellar electrokinetic chromatography modality. Borate buffer at pH 8.2 was used, and sodium dodecyl sulphate was added to the background electrolyte as surfactant. A range of linearity was determined and calibration curves were plotted for all the analytes.
Aim: this work gives a chemical description and sensory evaluation of several Pinot noir wines from different parts of Italy. For three subsequent years (2016-2018) the wine samples were submitted for in an Italian annual national Pinot noir competition aiming to define the best Pinot noir red wine from Italy. All of the wine samples were 3-years old (from vinification) at the moment they were analysed and evaluated; they were also registered for the competition the same year they were put on the market.Methods and results: all the wines were evaluated by a tasting panel composed of oenologists and wine experts, using the overall sensory quality as the descriptor. For the chemical screening, standard oenological chemical parameters (total acidity, colour, alcohol degree, total phenolic content, tannin indexes, etc.) and the content of the most abundant phenolic molecules by means of LC-MS analysis (triple quadrupole with internal standards) were determined. Pinot noir red wines produced from different parts of Italy showed a high variability for most standard wine chemical parameters considered, while the content of most single phenolic constituents was more retained and consistent with data from literature; except for t-resveratrol, which was significantly higher in our analyses, and delphinidin-3-glucoside, which was lower. Moreover, changes regarding the corresponding wines from the three vintages were noted. A correlation between the chemical parameters and the tasting panel results was also attempted. The results from a statistical analysis confirmed that alcoholic content, malvidin-3-glucoside and total anthocyanins had the highest positive impact on quality scores, while gallic acid, color tonality and total phenolic content had the highest negative.Conclusions: our results indicate that most wine producers have a conservative attitude with very slight differences found in the corresponding wines over the three years of investigation. The strong effects of agronomical, winemaking and ageing processes on chemical and sensorial features of Pinot noir red wines from Italy were also clearly shown. Compared to other monovarietal Pinot noir red wines from the same temperate area, single polyphenol content tended to be more retained than most standard chemical parameters.Significance and impact of the study: an overall quality assessment of a monovarietal wine, with its typicity as the main goal of a sensorial investigation, appears to be different from an objective quality assessment carried out by trained professional personnel using single standardised descriptors. Positive and negative correlations exist between sensorial judgement and chemical parameters, and the multiple linear regression model revealed relationships between the wine score and the set of the most important wine score description parameters.
Potatoes (Solanum tuberosum L.) are one of the most valuable agricultural crops, and the flesh of these tubers provides various classes of healthy compounds important for human nutrition. This work presents the results of a joint analysis of different chemical classes of compounds which provided insights on the metabolic characterization of pigmented and non-pigmented potato varieties collected from Italy. The identification of common or individual metabolic characteristics across the omic datasets (antioxidants, total polyphenolic content, polyphenols, and sugars) is conducted by Joint and Individual Variation Explained (JIVE), a data fusion multivariate approach. The common part of the multivariate model allowed the separation between non-pigmented and pigmented samples. Polyphenolic compounds were mainly responsible for the separation between purple-fleshed and red-skinned potatoes. An additional detailed analysis of the anthocyanin composition, including the acylated anthocyanins, allowed to pinpoint the diversities between the pigmented potato groups. Furthermore, the presence of an appreciable amount of hydroxycinnamic acids and anthocyanins in the purple-fleshed varieties, which are also characterized by a lower content of sugars, is found. Our results provide scientific evidence for the promotion of promising potato cultivars, which are characterized by a remarkable amount of various health benefit compounds.
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