Although peas are widely consumed legumes throughout the world, the bioactivity of the peptides released by the gastrointestinal digestion has not been sufficiently studied so far. The objective of ...the present work was to evaluate the potential of flours and protein isolates obtained from two varieties of yellow peas as sources of antioxidant peptides. Flours and protein isolates were prepared and submitted to a simulated gastrointestinal digestion. Protein hydrolysis degree (TNBS method) and protein solubility (in phosphate buffer saline, pH = 7.4) values were independent on the starting material. Antioxidant activity measured by oxygen radical absorbance capacity (ORAC) and hydroxyl radical averting capacity (HORAC) showed no differences between varieties. A lower activity was registered for protein isolates with respect to flours in the case of HORAC, which could be associated with a loss of molecules with molecular masses lower than 43 kDa in the protein isolates. A significant increase in activities was evidenced by both methods after gastrointestinal digestion, except in the case of HORAC activity of flours. Digested from protein isolates presented a greater ratio of molecules smaller than 1.4 kDa and a lower ratio of those larger than 6.5 kDa with respect to digested flours, according to electrophoresis and gel filtration chromatography studies. Results suggested that the presence of other components or/and the initial state of proteins would affect proteolytic attack of digestive enzymes. Both, pea flours and protein isolates, present interesting potential as antioxidants food ingredients.
Flours and protein isolates did not presented differences in molecular composition before and after gastrointestinal digestion and in proteolysis degree between peas varieties. Gastrointestinal digestion produced an increment in the capacity of peroxyl radicals scavenging of water‐soluble fractions of flours and protein isolates and in the inhibition of hydroxyl radical's formation only in the case of protein isolates. These facts could be associated with some differences in the molecular composition registered between flour digests and protein isolate digests.
Several observations highlight the importance of the carbohydrate moiety for the biological activity of antitumoural anthracyclines. Here is reported the synthesis, cytotoxicity and topoisomerase ...II-mediated DNA cleavage intensity of the new oligosaccharide anthracyclines 1--4 modified in the sugar residue. Evaluation of cytotoxic potency on different cell lines, resulted in quite similar values among the different analogues. On the other hand, topoisomerase II-mediated DNA breaks level was different for the various compounds, and was not related to cytotoxicity, thus supporting previous observations reported for some monosaccharide anthracyclines modified in the carbohydrate portion.
The recently confirmed neutron-shell closure at N = 32 has been investigated for the first time below the magic proton number Z = 20 with mass measurements of the exotic isotopes K-52,K-53, the ...latter being the shortest-lived nuclide investigated at the online mass spectrometer ISOLTRAP. The resulting two-neutron separation energies reveal a 3 MeV shell gap at N = 32, slightly lower than for Ca-52, highlighting the doubly magic nature of this nuclide. Skyrme-Hartree-Fock-Bogoliubov and ab initio Gorkov-Green function calculations are challenged by the new measurements but reproduce qualitatively the observed shell effect.
Analysis of a global eddy-resolving simulation using the NEMO general circulation model is presented. The model has 1/16° horizontal spacing at the Equator, employs two displaced poles in the ...Northern Hemisphere, and uses 98 vertical levels. The simulation was spun up from rest and integrated for 11 model years, using ERA-Interim reanalysis as surface forcing. Primary intent of this hindcast is to test how the model represents upper ocean characteristics and sea ice properties. Analysis of the zonal averaged temperature and salinity, and the mixed layer depth indicate that the model average state is in good agreement with observed fields and that the model successfully represents the variability in the upper ocean and at intermediate depths. Comparisons against observational estimates of mass transports through key straits indicate that most aspects of the model circulation are realistic. As expected, the simulation exhibits turbulent behaviour and the spatial distribution of the sea surface height (SSH) variability from the model is close to the observed pattern. The distribution and volume of the sea ice are, to a large extent, comparable to observed values. Compared with a corresponding eddy-permitting configuration, the performance of the model is significantly improved: reduced temperature and salinity biases, in particular at intermediate depths, improved mass and heat transports, better representation of fluxes through narrow and shallow straits, and increased global-mean eddy kinetic energy (by ∼ 40 %). However, relatively minor weaknesses still exist such as a lower than observed magnitude of the SSH variability. We conclude that the model output is suitable for broader analysis to better understand upper ocean dynamics and ocean variability at global scales. This simulation represents a major step forward in the global ocean modelling at the Euro-Mediterranean Centre on Climate Change and constitutes the groundwork for future applications to short-range ocean forecasting.
The recently confirmed neutron-shell closure at N=32 has been investigated for the first time below the magic proton number Z=20 with mass measurements of the exotic isotopes K52,53, the latter being ...the shortest-lived nuclide investigated at the online mass spectrometer ISOLTRAP. The resulting two-neutron separation energies reveal a 3 MeV shell gap at N=32, slightly lower than for Ca52, highlighting the doubly magic nature of this nuclide. Skyrme-Hartree-Fock-Bogoliubov and ab initio Gorkov-Green function calculations are challenged by the new measurements but reproduce qualitatively the observed shell effect.
Synthesis of 14-fluorodoxorubicin Berettoni, M.; Cipollone, A.; Olivieri, L. ...
Tetrahedron letters,
04/2002, Letnik:
43, Številka:
15
Journal Article
Recenzirano
Synthesis of the novel anthracycline 14-fluorodoxorubicin is described. A key step in the synthesis is the hydrolysis of 14-bromo,14-fluoro derivative
14
with AgBF
4 and DMSO, to give the geminal ...fluorohydrin system.
Graphic
Anthracycline antibiotics play an important role in cancer chemotherapy. The need for an improvement of their therapeutic index has stimulated an ongoing search for anthracycline analogues with ...improved properties. Analogue development was originally limited by a lack of information on the cellular drug target, nevertheless almost 20 years ago the mechanism of action of doxorubicin and daunorubicin was revealed and DNA topoisomerase II was recognised to be their main cellular target. Several anthracyclines interfere with topoisomerase II functions by stabilizing a reaction intermediate in which DNA strands are cut and covalently linked to tyrosine residues of the enzyme. Investigations on the sequence specificity of doxorubicin in vitro and in nuclear chromatin of living cell have led to a molecular model of drug receptor on the topoisomerase II-DNA complex. Anthracyclines are likely placed at the interface between the DNA cleavage site and the active site of the enzyme, forming a DNA-drug-enzyme ternary complex. Moreover, a quite detailed structure-function relationship has been established for anthracyclines. First, drug intercalation is necessary but not sufficient for topoisomerase II poisoning; second, the removal of the 4-methoxy and 3'-amino substituents greatly increases the drug activity and third, the 3' substituent of the sugar moiety markedly influences the sequence selectivity of anthracycline-stimulated DNA cleavage. These relationships have been exploited during the last decade by several groups, including ours, in the search for new anthracycline drugs with lower side effects and higher activity against resistant cancer cells. This review will focus on areas of the anthracycline field including synthesis of new analogues, new strategies of synthesis and recent developments in the area of drug delivery.
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