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Ergothioneine (ESH), an aromatic thiol occurring in the human diet and which accumulates in particular cells, is believed to act as an antioxidant. However, its redox mechanism remains unclear and it does not seem to provide any advantage compared to other antioxidants, such as alkylthiols, which are better reducing agents and generally present in cells at higher levels. Here, we investigated by ESI-MS the products of ESH oxidation produced by neutrophils during oxidative burst and, to further elucidate ESH redox behavior, we also analyzed the oxidation products of the reaction of ESH with hypochlorite in cellfree solutions. Indeed, neutrophils are the main source of hypochlorite in humans. Furthermore, we also tested other biologically relevant oxidants, such as peroxynitrite and hydrogen peroxide. Our results indicate that treatment of human neutrophils with phorbol 12-myristate 13-acetate in the presence of ESH leads to a remarkable production of the sulfonated form (ESO3H), a compound never described before, and hercynine (EH), the desulfurated form of ESH. Similar results were obtained when ESH was subjected to cell-free oxidation in the presence of hypochlorite, as well as hydrogen peroxide or peroxynitrite. Furthermore, when the disulfide of ESH was reacted with those oxidants, we found that it was also oxidized, with production of EH and ESO3H, whose amount was dependent on the oxidant strength. These data reveal a unique ESH redox behavior, entirely different from that of alkylthiols, and suggest a mechanism, so far overlooked, through which ESH performs its antioxidant action in cells.

Industrial fruit products were investigated for their content of pectin methylesterase (PME) residual activity by a new procedure that allows selective concentration by affinity chromatography of the active form of the enzyme, when present. The technique utilizes a protein inhibitor, purified from kiwifruit, covalently bound to a Sepharose resin. This inhibitor, in fact, binds with high affinity the native active form of PME that can be subsequently recovered by dissociating the complex at alkaline pH with high ionic strength. In this way the enzyme is recovered at a concentration suitable for pH-stat assay. We examined fruit products from several industrial preparations of peach, pear, apple, apricot and pineapple. The analysed fruit purees showed PME activities between 10 ‐3 and 10 ‐5 U/mL, whereas the nectars did not show any detectable activity although cloud loss phenomenon was often observed. The diced fruit samples showed activities between 10 ‐2 and 10 ‐5 U/g. The highest values were found in samples of chi grape (10 ‐2 U/g) and pineapple (10 ‐3 U/g). A dependence of the intensity of cloud loss on the levels of PME residual activity was found.

""The presence of pipecolic acid and pipecolic acid betaine, also known as homostachydrine, is herein reported for the first time in Citrus genus plants. Homostachydrine was found in fruits, seeds, and leaves of orange, lemon, and bergamot (Citrus bergamia Risso et Poit). As homostachydrine was not commercially available, as a comparative source, extracts of alfalfa leaves ( Medicago sativa L.) were used, in which homostachydrine is present at high concentration. Then, the results where confirmed by comparison with an authentic standard synthesized and purified starting from pipecolic acid. The synthesized standard was characterized by a ESI-MS\\\/MS study using a 3D ion-trap mass spectrometer. When subjected to MS\\\/MS fragmentation in positive ion mode, homostachydrine, unlike its lower homologue proline betaine (also known as stachydrine), showed a pattern of numerous ionic fragments that allowed unambiguous identification of the compound. For the quantitation in the plant sources, high sensitivity and specificity were achieved by monitoring the transition (158 --> 72), which is absent in the fragmentation patterns of other major osmolytes commonly used as markers for studies of abiotic stress. As for the metabolic origin of homostachydrine, the occurrence in citrus plants of pipecolic acid leads to the hypothesis that it could act as a homostachydrine precursor through direct methylation""

" It was found that the most represented osmolytes in the juices, that is, L-proline, stachydrine, and betonicine, can be quantified with minimal sample preparation and short analysis time (about 1 min) also by flow injection analysis (FIA) ESI-MS\/MS with the same results as obtained by HPLC ESI-MS\/MS. In all of the juices, discrete amounts of choline and trigonelline were present. Conversely, GabaBet was always below detection limits. Notably, N-methyl-L-proline and 4-hydroxy-L-prolinebetaine, which were discovered for the first time in the juice of bergamot (Citrus bergamia Risso et Poit), are also present in all of the citrus juices examined"

"Proline and 4-hydroxy-L-proline levels in the samples were also determined by HPLC analysis with fluorescence detection and the results compared to those obtained with HPLC-ESI-tandem mass spectrometry. For the first time, the presence of N-methyl-L-proline and 4-hydroxy-L-prolinebetaine in the fruits of a plant of the Citrus genus is reported"

BACKGROUND: The elemental content of Sicilian red orange juices and the bioaccessibility of many elements of particular nutritional interest was evaluated. RESULTS: The elemental content of fresh juices from Sicilian blood oranges was analysed by ICP-OES, GF AAS, HG-AAS and CVAAS. Among the macroelements (Na, Ca, K,Mg and P), potassium occurred in the greatest amount, with 3.64% of the requested RDA for 100 mL of juice daily intake. The values of RDA 100 mL-1 of juice for Mg, P, Ca and Na resulted 1.61%, 1.26%, 0.59% and 0.09% respectively. For the trace elements Cr, Cu and Se, the RDA 100 mL-1 of juicewere 9.20%, 7.14% and 1.82%, respectively. In vitro tests simulating the digestive process showed high bioaccessibility only for boron and manganese while that of copper, zinc and iron were consistently lower. CONCLUSIONS: Sicilian blood orange juices gave different results from non-pigmented orange juices interms of a higher content of copper, boron and lower content of chromium and manganese. However, among the nutritionally important elements, only manganese showed high bioaccessibility. The low bioaccessibility found for iron, zinc and copper is likely due to the presence in the orange juice of ligands such as polyphenols and organic acids.

The aim of this study was to explore the molecular mechanisms involved in late preconditioning-induced cell protection in endothelial cells.

L'uso ideologico della musica da parte del potere politico nella Roma augustea è ampiamente documentato negli scritti greci e latini e nelle testimonianze iconografiche. In particolare, le rappresentazioni degli eventi sonori descritti nei programmi figurativi e nelle opere letterarie commissionate da Augusto o a lui dedicate sono uno dei tasselli significativi della propaganda politica imperiale. Gli aspetti sonori e le esperienze musicali di tale programma celebrativo di Roma e del suo princeps sono qui presentate attraverso, rispettivamente, una rassegna di testi e una lettura iconografica. La prima comprende riflessioni e approfondimenti sul significato attribuito alle rappresentazioni verbali della musica nei testi di Strabone, Virgilio, Dionisio di Alicarnasso e Vitruvio. La seconda esamina il significato attribuito sia alle rappresentazioni di Apollo e di Ercole come musicisti. Esse diverranno modelli più volte imitati. In particolare, è qui esaminata la persistenza e la reinvenzione dell'iconografia di Ercole citaredo: un'immagine che ha assunto nuovi significati e nuove funzioni presso i primi collezionisti di antichità, nei libri di emblemi e negli usi encomiastici e celebrativi delle corti italiane dal Quattrocento al Seicento.

A method for the determination of a low level of pectin methylesterase activity from vegetable products is described. The method is based on an affinity chromatography technique that employs a resin-bound pectin methylesterase inhibitor, purified from kiwi fruit, which selectively binds the pectin methylesterase. The resin has the capacity to concentrate the enzyme, allowing measurement of enzyme activities too low to be determined by commonly employed techniques and commensurate with those found in pasteurized food products. The enzyme is eluted from the resin at alkaline pH (9.5) and assayed by a pH-stat method. Depulped orange juices containing different amounts of pectin methylesterase were prepared and used to determine enzyme recovery. The results show a recovery of 90% with a standard deviation of 6.8%.