Ricerc@Sapienza

Linear ω-phenylalkylamines of increasing alkyl chain length have been investigated employing synchrotron radiation in the photon energy range from 7 to 15 eV. These molecules have received considerable interest because they bear the skeleton of biologically relevant compounds including neurotransmitters and because of the possible interaction between the amino moiety and the phenyl ring. Recently, the contribution of this interaction has been assayed in both neutral and protonated species, pointing to a role of the polymethylene chain length.

The binding motifs in the halide adducts with tyrosine ([Tyr + X]-, X = Cl, Br, I) have been investigated
and compared with the analogues with 3-nitrotyrosine (nitroTyr), a biomarker of protein nitration, in a
solvent-free environment by mass-selected infrared multiple photon dissociation (IRMPD) spectroscopy
over two IR frequency ranges, namely 950–1950 and 2800–3700 cm-1. Extensive quantum chemical
calculations at B3LYP, B3LYP-D3 and MP2 levels of theory have been performed using the 6-311++G(d,p)

Low-energy collision induced dissociation (CID) of deprotonated L-cysteine S-sulfate, [cysS-SO3],- delivered in the gas phase by electrospray ionization, has been found to provide a means to form deprotonated L-cysteine sulfenic acid, a fleeting intermediate in biological media. The reaction mechanism underlying this process is the focus of the present contribution. At the same time other novel species are formed, which were not observed in previous experiments.

The study of Pt(IV) antitumor prodrugs able to circumvent some drawbacks of the conventional Pt(II) chemotherapeutics is the focus of a lot of attention. This paper reports a thorough study based on experimental methods (reduction kinetics, electrochemistry, tandem mass spectrometry and IR ion spectroscopy) and quantum–mechanical DFT calculations on the reduction mechanism of cisplatin-based Pt(IV) derivatives having two hydroxido (1), one hydroxido and one acetato (2), or two acetato ligands (3) in axial position.

Infrared multiple photon dissociation (IRMPD) spectroscopy allows for the derivation of the vibrational fingerprint of molecular ions under tandem mass spectrometry (MS/MS) conditions. It provides insight into the nature and localization of posttranslational modifications (PTMs) affecting single amino acids and peptides.

Protonation at the formyl oxygen atom of benzaldehydes leading to the formation of carboxonium ions yields two distinct isomers, depending on the relative orientation of the proton either cis or trans with respect to the hydrogen atom on the adjacent carbon. In this context, the IR multiple photon dissociation (IRMPD) spectra of protonated ortho, meta, and para-hydroxybenzaldehydes (OH−BZH+), delivered into the gas phase by electrospray ionization of hydro-alcoholic solutions, are reported in the 3200–3700 cm−1 spectral range.

The aim of the present work has been the mass spectrometry characterization of the Nimotuzumab (NIM) antibody chemically modified with the bifunctional chelating agent para-S-2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraaza cyclododecanetetraacetic acid (p-SCN-Bn-DOTA).

The capability to deposit intact highly pure ionic species makes ion soft landing an advantageous mass spectrometric method able to create molecular layers on solid surfaces. Recent advances in this technique gave the possibility to manipulate solvent-free ions in open-air conditions. The high ionic current produced by the new sources as well as the developments of accelerated systems dramatically increase the efficiency of the soft landing process, opening new opportunities for surface modification with self-organized polyatomic structures.

This paper reports on the first phytochemical analysis ever performed on Jasminum tortuosum Willd. This analysis, mainly carried out by means of column chromatography separation, NMR spectroscopy and mass spectrometry, led to the isolation and the identification of four compounds, namely the lignans ginkgool (1) and olivil-4'-O-beta-glucopyranoside (2) and the secoiridoids oleoside dimethyl ester (3) and oleoside 11-methyl ester (4).

GADD45? is selectively and constitutively expressed in Multiple Myeloma cells, and this expression correlates with an unfavourable clinical outcome. GADD45? physically interacts with the JNK kinase, MKK7, inhibiting its activity to enable the survival of cancer cells. DTP3 is a small peptide inhibitor of the GADD45?/MKK7 complex and is able to restore MKK7/JNK activation, thereby promoting selective cell death of GADD45?-overexpressing cancer cells.