308 research outputs found
Understanding the structural specificity of Tn antigen for its receptor: An NMR solution study
No full textThe present work aims at understanding the structural basis of the biological recognition of Tn antigen (GalNAc-α-O-L-Ser), a specific epitope expressed by tumor cells, and the role of its amino acidic moiety in the interaction with its receptor (the isolectin B4 extracted from Vicia villosa). An NMR structural characterization of the α and β anomers, based on J couplings and molecular modeling revealed a structure in very good agreement with data reported in literature for variants of the same molecules. In order to demonstrate the involvement of the amino acid in the ligand–receptor recognition, also GalNAc-α-O-D-Ser was studied; the change in the stereochemistry is in fact expected to impact on the interaction only in case the serine is part of the epitope. Relaxation properties in the presence of the receptor clearly indicated a selective recognition of the natural L form, probably due to the formation of a water-mediated hydrogen bond with Asn 129 of the protein
ELECTROCHEMICAL METHODS FOR THE SUSTAINABLE RECOVERY OF GADOLINIUM FROM MRI CONTRAST AGENTS AND FOR THE FABRICATION OF GADOLINIUM-RICH NANOPARTICLES.
No full textThe widespread use of gadolinium-based contrast agents (GBCAs) in magnetic resonance imaging (MRI) has led to increasing concern over the release of gadolinium into the environment. Gadolinium (Gd) is excreted in complexed forms that are stable and difficult to remove through conventional wastewater treatments, posing both environmental and health-related risks. To address this issue, this work explores two electrochemical strategies aimed at the sustainable recovery and reuse of Gd: a degradation method for GBCAs in various matrices, and the synthesis of Gd-containing nanoparticles starting from GBCA model compounds.
In the first approach, electrochemical tests were carried out on different matrices containing GBCAs, including production wastewater and artificial urine. Good results were obtained across various conditions, supporting the versatility and applicability of the method. The process enabled Gd recovery from solution while reducing the chemical oxygen demand (COD) of the matrix. This dual effect highlights the potential of electrochemical treatments not only to recover valuable metals, but also to improve the overall quality of the treated wastewater.
The second part of the study focused on the synthesis of Gd-containing zinc hexacyanoferrate nanoparticles through an electrochemical process. Gd3+ ions were successfully incorporated into the particles and are likely retained near their surface, potentially enhancing interaction with water molecules, a key feature for MRI applications. These nanoparticles could represent a promising alternative to conventional GBCAs, with the possibility of tuning gadolinium content to achieve high contrast efficiency. However, further studies are needed to assess their biocompatibility and actual performance as contrast agents.
Overall, the two approaches offer complementary solutions for the management of GBCA-related waste: one aiming at direct Gd recovery from wastewater, and the other enabling the transformation of Gd into functional nanomaterials. Both contribute to mitigating environmental impact while promoting a circular approach to critical raw materials
ELECTROCHEMICAL IODINATION AND DEIODINATION PROCESSES FOR GREEN SYNTHESIS AND WATER REMEDIATION
No full textThis project is devoted to highlight the importance and the great innovation that the application of electrochemistry could bring in the protection of the environment. The aim was to develop cost-effective and eco-friendly methods in both environmental remediation and green chemistry fields, to make electrochemistry considered as a valid alternative to classical methods in the contrast media industry. The first part of the thesis is focused on the study of the electrochemical iodination of N,N’-(2,3-dihydroxypropyl)-5-hydroxy-1,3-benzenedicarboxamide (idroamide, IA), an important intermediate for the synthesis of iomeprol (IMP). It has been demonstrated that the use of a carbonaceous anode can successfully transform I-/I2 in iodinating species, leading to a complete iodination of the reagent and almost no by-products. The experimental conditions have been optimized and the potentiostatic electrolysis in a recirculating divided cell (cation exchange membrane) has been successfully scaled for the treatment of 0.8 L of IA 23.5% w/w. A pre-pilot system has been designed and installed and the first tests showed the way forward from here. Parameters related to increasing volumes will be studied, also optimising them for flow chemistry. The success of the scale-up of this study will provide a concrete, as well as green, alternative to the current use of ICl, a highly corrosive iodinating agent that must be handled with great caution. The second part of this work is instead focus on iodinated contrast media (ICM) electrochemical degradation, and, in particular, on reductive processes. Gold was found to be a powerful electrocatalyst in the case of C-I bond breaking and a preliminary study on sputtered 10 nm bilayer films showed promising results about a powerful synergy between gold and silver. The reductive mechanism was also investigated for IMP deiodination, allowing the optimization of the experimental parameters in conditions similar to those of real polluted matrices. Iodine was almost completely recovered as iodides in this case, while in simulated urine and industrial wastewater, where an undivided cell was chosen to promote mineralization, it was accumulated as iodates. Further development will be focused on iodides separation from the polluted matrix, in a iodine circular economy perspective
VALORIZATION OF POLYHYDROXYLATED AND HALOGENATED COMPOUNDS THROUGH ELECTROCHEMICAL OXIDATION-REDUCTION REACTIONS
No full textThe growing population and consequent production of food, energy and materials is increasing the pressure on non-renewable fossil resources, with a consequent climate awareness. As a consequence, renewable energy-based processes are experiencing an acceleration. A significant number of environmental-friendly procedures and processes based on renewable raw materials have been reported in recent years, trying to replace the petroleum-based industry. Electrosynthesis is an approach, so far undervalued, with a huge potential to allow the shift from conventional fossil-based towards real sustainable chemistry. Electrochemistry can exploit the excess renewable electricity to convert feedstocks into commodity chemicals and industrial synthons, increasing the production efficiency and reducing environmental impact along the entire value chain.
Until few years ago, electrochemistry was regarded as a specialized niche, with only few industrial processes available like the chlor-alkali process. But, also thanks to the increasing use of renewable energies, it has been shown that electrochemical routes can be more advantageous than the chemical ones. Thus, an upscaling of the most promising electrochemical processes will be necessary in the short-term future. In this context of increasing importance of electrochemistry as a valuable ally for displacing petrochemical industrial processes, the aim of this PhD project was to study organic electrochemistry applied to the synthesis of polyhydroxylated compounds of industrial interest and to the degradation of halogenated pollutants
Unexpected structural properties of LnIII complexes formed with the heptadentate AAZTA ligand
No full textDiagnostic Agents Selective agains Metalloproteinases
No full textThe invention relates to aryl-sulfonamido compds. endowed with affinity against metallo proteases MMP, having formula
(I) below wherein R, R1, R2, R3, G and n have the meanings reported in the specification, properly labeled with
diagnostic imaging moieties or even radiotherapeutic moieties. The invention also refers to the process for their prepn.,
to pharmaceutical compns. comprising them and to their use as diagnostic imaging agents or radiotherapeutic agents.
The invention relates to arylsulfonamido compds. of formula I, which endowed with affinity against metalloproteases
MMP and are useful as diagnostic imaging agents. The invention also refers to the process for their prepn., to
pharmaceutical compns. comprising them and to their use as diagnostic imaging agents or radiotherapeutic agents.
Compds. of formula I wherein R is -Ar-X-Ar1; Ar is (un)substituted (hetero)arylene and (un)substituted (hetero)aryl; Ar1 is
(un)substituted (hetero)aryl and H; X is a single bond, (un)branched C1-4 alkylene, O, S, SO2, CO, NH and derivs.,
NHCO and derivs., and CONH and derivs.; R1 is H, OH, Ra and ORa; Ra is (un)branched C1-4 alkyl, C2-4 alkenyl and -
(CH2)0-4-Z-(CH2)0-4-W; Z is a single bond, O, NH and derivs., NHCO and derivs., and CONH and derivs.; W is
(un)substituted Ph and (un)substituted 5- to 6-membered heterocycle; R2 and R3 are independently H, (un)substituted
(un)branched C1-4 alkyl and a zinc binding group; G is (un)branched C1-6 alkyl, (hetero)aryl, arylalkyl and -(CH2)1-6-
NH2 and derivs.; and their pharmaceutically acceptable salts thereof, are claimed. Example compd. II·2CF3COOH was
prepd. via hydroxyamidation of the corresponding acid with O-(tert-butyldimethylsilyl)hydroxylamine. All the invention
compds. were evaluated for their metalloprotease inhibitory activity. From the assay, it was detd. that II exhibited the
IC50 value of 0.3 ± 0.03 nM and 0.2 ± 0.01 nM against MMP2 and MMP13, resp
Process for the iodination of phenolic derivates
No full textThe present invention relates to a process for the preparation of iodinated phenols; in particular; it relates to a process including the direct iodination, with suitably activated iodine, of 3,5-disubstituted phenol compounds to the corresponding 3,5-disubstituted-2,4,6-triiodophenols, which are useful intermediates for the synthesis of x-ray contrast media, and to the preparation of the contrast media themselves
Enzymatic synthesis of the Tn antigen
No full textThe enzymatic synthesis of the Tn antigen (GalNAc--O-Ser), a glyco-aminoacid of great biological importance, is reported. The reaction was promoted by commercial -N-acetylgalactosaminidase from Acremonium sp., using p-nitrophenyl--N-acetylgalactosamine as the donor. The kinetics were monitored by capillary electrophoresis and LC–UV-MS. For unprotected serine, the role of pH and temperature was investigated, finding that pH 5 and T=18 ◦C gave the best yield. Under these conditions a significant increase of the reaction rate was observed in comparison
with previous literature data, using unprotected serine. The role of the bulkiness of the serine protecting groups on the yield was additionally considered, as well as the kinetic profiles generated by the use of two differently protected aminoacids. By proper choice of the protecting group, the reaction yield then increased from 5% (with unprotected serine) to about 50% (with N-Boc and N-methoxycarbonyl serine)
Arylsulfonamido compounds as metalloprotease inhibitors and their preparation, pharmaceutical compositions and use as diagnostic as well as radiotherapeutic agents
No full textThe invention relates to aryl-sulphonamido compounds endowed with affinity against metallo proteases MMP, having formula (I) below wherein R, R 1 , R 2 , R 3 , G and n have the meanings reported in the specification, properly labelled with diagnostic imaging moieties or even radiotherapeutic moieties. The invention also refers to the process for their preparation, to pharmaceutical compositions comprising them and to their use as diagnostic imaging agents or radiotherapeutic agents
Un ricordo personale di Fulvio Papi
No full textThe article reflects on Fulvio Papi’s philosophical approach, highlighting his dedication to simplifying complex ideas to reveal underlying truths. The author recounts personal interactions that demonstrate Papi’s ability to engage deeply yet succinctly with philosophical concepts, enhancing understanding and discussion. The article underscores Papi’s impact through his commitment to clarity and ethical simplicity, leaving a lasting legacy in philosophical discourse
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