169,777 research outputs found
Oli extravergini di oliva da agricoltura biologica e convenzionale a confronto: parametri di qualità – Risultati preliminari
No full textMetalli in tracce in spezie ed in prodotti erboristici
No full textStudio del contenuto in metalli in tracce in campioni di spezie e prodotti erboristici presenti sia nei punti vendita non convenzionali che convenzionali mediante GFAAS
Anima del Fuoco. Da Eraclito a Tiziano da Previati a Plessi
No full textmembro del comitato scientifico della mostra e autore di un saggio inserito nel Catalog
The excretion of tryptophan metabolites in patients with different forms of haemoblastosis
No full textThe urinary excretion of Kynurenine, 3-hydroxy-kynurenine, kynurenic and xanthureinic acid has been determined in 61 patients with different forms of haemoblastosis. A anormal urinary excretion of some metabolites of tryptophan is frequent, but not costant
Distribution of metals and phenolic compounds as a criterion to evaluate variety of berries and related jams
No full textPolyphenols, anthocyanins, phosphate, iron, zinc, manganese, calcium, potassium, magnesium and sodium were evaluated both in berries belonging to the genera Rubus and Ribes and in related jams by means of spectrophotometric techniques, to verify a possible differentiation on the basis of these parameters. The phenolic and anthocyanins higher contents were detected for black currant fruits and jams. Regarding the total phenolic content, in 11 cases it is possible to observe a higher content in jams with respect to the related row fruits. All samples contain a high amount of potassium, calcium and magnesium but small quantities of sodium. Phosphate is abundant especially in currants. As regard jams all results about metals are lower than those obtained for fruits, this is due to the dilution during the preparation of the jams. Multivariate statistical analysis shows that on the basis of obtained analytical results it is possible differentiate not only fruit but also the derived jams. (c) 2005 Elsevier Ltd. All rights reserved
Valutazione e selezione di genotipi di olivo tolleranti il freddo in Emilia
No full textL'olivo è una specie di origina subtropicale che si spinge fino ai climi temperati, con notevole adattamento alle varie temperature. Dall'analisi dei dati,sono emerse importanti considerazioni sulla tolleranza e suscettibilità di alcune accessioni emiliane. Pur se raro, il carattere di vera e propria resistenza alle basse temperature è presente in Olea europea
Sweet cherry leaf composition as influenced by genotype, rootstock and orchard management
No full textIn one of the most important Italian regions for sweet cherry cultivation (Vignola), 2 orchards under conventional and organic management were considered. In both orchards leaf analyses were conducted on 3 cultivars (Burlat C1, Cristalina and Giorgia) grafted on 2 different rootstocks (Colt and MaxMa 14). No mineral fertilizers were applied in the orchard under organic management. In general, the mineral elements levels were low for N, Mn and Zn and acceptable or adequate for the other elements considered. The influence of genotype, rootstock and orchard management is discussed. The results showed that differences in mineral element composition were influenced by genotype and rootstock, while management didn’t have a strong influence. In particular, genotype affected P and B concentrations and rootstock modified P, K and B concentrations
Separation by solid phase extraction and quantification by reversed phase HPLC of sulforaphane in broccoli
No full textThe separation and quantification of sulforaphane [1-isothiocyanato-4-(methylsulfinyl)-butane] from the florets, stalks and leaves of broccoli is described. The procedure uses solvent extraction, followed by purification of extracts using solid phase extraction (SPE) and reverse phase HPLC analysis. The HPLC method is compared with a spectrophotometric assay. To obtain information about the usefulness of acid hydrolysis of glucosinolates, the florets were left to autolyze at room temperature or were treated with concentrated hydrochloric acid, then analysed. The method proves reliable and reproducible as regards both SPE purification and chromatographic determination. Quantities of sulforaphane were found in the florets, stalks and leaves. The highest content of sulforaphane (110 mu g g(-1)) was found in the leaves. (C) 1998 Elsevier Science Ltd. All rights reserved
Identification and quantification of phenylpropanoid glycosides in Aloysia polystachya (Griseb and Moldenke) by HPLC-TQMS
No full textData on the chemical composition of Aloysia polystachya (Griseb. et Moldenke) are poor in the literature. It is an herbaceus plant, widely distributed in subtropical regions of South America where it is commonly known as “tè burro”. It is widely used as a dietary supplement or tea substitute and in folk medicine. Phenolic compounds characterization in plant matrix can be very difficult, owing to the bonding to different sugar moieties, or conjugation to form complex structures. Among the different methods available, high-performance liquid chromatography (HPLC) is preferable for the separation and quantification of polyphenolics. In present work the HPLC-MS characterization and quantification of the phenylpropanoid glycosides fraction, purified by Solid Phase Extraction (SPE), of Aloysia polystachya (Griseb. et Moldenke) extracts was performed.
Three different MS techniques have been coupled to HPLC, to identify and quantify the compounds present in the extracts: ion trap mass spectrometry (Ion Trap LC/MS), and the quadrupole-time of flight high resolution mass spectrometry (Q-TOF HRMS) for the identification and HPLC-TQMS in MRM mode for the quantification, using verbascoside as reference standard. Nine phenylpropanoid glycosides were identified and quantified after SPME purification of methanolic extract of Aloysia polystachya leaves. Among them, the compounds forsythoside A, plantainoside C, purpureaside D, martynoside and its two isomers were identified here for the first time.
The content of phenylpropanoid glycosides ranges from 3.3 mg/g for verbascoside to 0.08 mg/g for purpureaside D.
The results present here could be helpful to assess the quality of Aloysia polystachya leaves. Knowledge of the content of phenylpropanoid glycosides could further contribute to the chemotaxonomy of the genus
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