A novel pathway for cytosine to uracil conversion performed in a micellar environment, leading to the generation of uridine monophosphate (UMP), was evidenced during the alkylation reaction of cytidine monophosphate (CMP) by dodecyl epoxide. Liquid chromatography-electrospray ionization - ion trap - mass spectrometry was used to separate and identify the reaction products and to follow their formation over time. The detection of hydroxy-amino-dodecane, concurrently with free UMP, in the reaction mixture suggested that, among the various alkyl-derivatives formed, CMP alkylated on the amino group of cytosine could undergo tautomerization to an imine and hydrolytic deamination, generating UMP. Interestingly, no evidence for this peculiar conversion pathway was obtained when guanosine monophosphate (GMP), the complementary ribonucleotide of CMP, was also present in the reaction mixture, due to the fact that NH(2)-alkylated CMP was not formed in this case. The last finding emphasized the role played by CMP-GMP molecular interactions, mediated by a micellar environment, in hindering the alkylation reaction at the level of the cytosine amino group.

A method using the combination of size exclusion-solid phase extraction and ultrafiltration, followed by tryptic digestion and analysis of the protein digest by liquid chromatography-electrospray ionization-3D ion trap-mass spectrometry (LC-ESI-3D IT-MS), was developed for the detection and quantification of caseinate traces potentially resulting from fining processes in white wines. In particular, several tryptic peptides generated from the main proteins constituting caseinate (β-, αS1-, and αS2-caseins) were used as markers of its presence in the wine matrices; among them, the β-casein peptide GPFPIIV was found to be the best marker for quantification purposes. Method linearity and sensitivity were assessed on a series of Italian commercial white wines, first checked for the absence of any peptide signal attributable to caseins introduced during their production and subsequently spiked with increasing concentrations of caseinate, to provide samples for matrix-matched calibrations. Limits of detection ranging between 0.09 and 0.29 mg/L (S/N = 3), according to the wine, were achieved using a 10 mL sample volume and the MS signal of GPFPIIV as the response related to the caseinate concentration. Such levels are comparable or even lower than the one (0.25 mg/L) recently adopted as a threshold by European Union legislation concerning the indication of milk- and egg-derived fining agents on wine labels, that is, the most restrictive one among those currently proposed in the world.

Peroxidation catalysed by Soybean Lypoxigenase was performed on tetralinoleyl-cardiolipin with the aim of generating selectively oxidized products, to be used subsequently as standards for studies on cardiolipin oxidation. The reaction products were characterized by LC-ESI-MS and MS/MS, and the process was found to link a hydroperoxylic group on one or more linoleic chains of cardiolipin, up to a total of four groups per molecule. Interestingly, the incidence of other oxidized products, like those arising from multiple hydroxylation or mixed hydroxylation-hydroperoxydation, previously observed after the chemical oxidation of the same cardiolipin, was found to be negligible. Moreover, evidences for the presence of the hydroperoxylic group(s) almost exclusively on carbon 13 of the linoleic chain(s) were obtained by MS/MS measurements. The enzymatic approach, integrated with a preparative separation step, which could be developed by adapting the chromatographic conditions adopted in the present work for analytical purposes, represents a promising strategy for the synthesis of highly specific mono- or multi-peroxidated derivatives of cardiolipins.

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The "grafting from" synthesis of core-shell molecularly imprinted polymer nanoparticles (Ser-MIP@SiO 2 NPs) has been applied to the development of an electrochemical sensor for Serotonin. Ser-MIP@SiO 2 NPs have been synthesized on preformed SiO 2 nanobeads by surface imprinting via reversible additionfragmentation chaintransfer (RAFT) polymerization. After polymerization, the reductive aminolysis of dithioesther end group has been carried out. Then MIP-nanoparticles were subsequently characterized by ATR-FTIR, TGA, TEM and XPS. The entrapment of core-shell Ser-MIP@SiO 2 NPs by the electropolymerization of PEDOT in an upside-down electrochemical cell has been investigated. Under selected conditions, results in sensing application for Serotonin are presented.