Ti(IV)/BINOL-catalyzed asymmetric aldol reaction of a masked acetoacetic ester: pronounced influence of catalyst concentration on nonlinear effects

Initial concentration of enantioenriched or enantiopure catalysts proved to be an important factor for the achievement of a more pronounced amplification of ee's in the Ti(IV)/BINOL-catalyzed aldol reaction of an O-silyldienolate.     

Mukaiyama-Michael vinylogous additions to nitroalkenes under solvent-free conditions

The first Mukaiyama-Michael vinylogous reaction of a dioxinone-derived silyl ether to nitroalkenes is reported. The conjugate addition is performed in absence of any catalyst under solvent-free conditions, proceeding with satisfactory efficiency with variously substituted nitroalkenes.     

Calculations of overtone NIR and NIR-VCD spectra in the local mode approximation: Camphor and Camphorquinone

We present a method to calculate near-infrared (NIR) and NIR-vibrational circular dichroism (NIR-VCD) spectra up to the second CH-stretching overtone region in the local mode approximation. Atomic polar tensors and atomic axial tensors are first evaluated by DFT methodology for all CH stretching coordinates with systematic positive and negative displacements off-equilibrium and therefrom anharmonic dipole moment functions are constructed by polynomial interpolations. No adjustable parameters are employed up to this point. Rotational and dipole strengths are finally calculated by evaluating transition moments of Morse-type wave-functions. The method is applied to the case of Camphor and Camphorquinone, for which relevant differences in the vibrational circular dichroism (VCD) data are observed, which are predicted by our approach. Further steps are still to be made for a more complete treatment: the ab initio evaluation of mechanical anharmonicity and the introduction of mechanical and electrical coupling between local modes.     

Photoreactivity of triazolopyridinones, including the drug trazodone, in aqueous solution

Irradiation of triazolo[4,3-a]pyridin-3-ones at 310 nm has been investigated in water/acetonitrile (7%). Cis-cisoid-fused cyclobutanes are generally obtained. Cage products are found starting from derivatives bearing (piperazin-1-yl)aryl moiety under dilute conditions (10⁻³ M). Two different routes appear to be involved in the formation of the observed photoproducts. A plausible mechanistic explanation is reported.     

Synthesis and evaluation as NOP ligands of some spiro[piperidine-4,2'(1'H)-quinazolin]-4'(3'H)-ones and spiro[piperidine-4,5'(6'H)-[1,2,4]triazolo[1,5-c]quinazolines

Some spiro[piperidine-4,2'(1'H)-quinazolin]-4'(3'H)-ones 3 and spiro[piperidine-4,5'(6'H)-[1,2,4]triazolo[1,5-c]quinazolines] 4 were synthesized and evaluated as ligands of the nociceptin receptor. The examined compounds showed partial agonistic activity, except compounds 3, 4n that proved to be pure antagonists.     

MIP sensors – the electrochemical approach

This review highlights the importance of coupling molecular imprinting technology with methodology based on electrochemical techniques for the development of advanced sensing devices. In recent years, growing interest in molecularly imprinted polymers (MIPs) in the preparation of recognition elements has led researchers to design novel formats for improvement of MIP sensors. Among possible approaches proposed in the literature on this topic, we will focus on the electrosynthesis of MIPs and on less common hybrid technology (e.g. based on electrochemistry and classical MIPs, or nanotechnology). Starting from the early work reported in this field, an overview of the most innovative and successful examples will be reviewed.     

Semilinear evolution transmission problems across fractal layers

A semilinear parabolic transmission problem across either a fractal layer S$S$ or the corresponding prefractal layer _Sh$S_h$ is studied. Local existence, uniqueness and regularity results for the mild solution, in both cases, are established as well as a sufficient condition on the initial datum for global existence is given. The asymptotic behaviour of the solutions of the approximating problems is studied.     

Mass spectrometry in the proteome analysis of mature cereal kernels

In the last decade, the improved performance and versatility of the mass spectrometers together with the increasing availability of gene and genomic sequence database, led the mass spectrometry to become an indispensable tool for either protein and proteome analyses in cereals. Mass spectrometric works on prolamins have rapidly evolved from the determination of the molecular masses of proteins to the proteomic approaches aimed to a large-scale protein identification and study of functional and regulatory aspects of proteins. Mass spectrometry coupled with electrophoresis, chromatographic methods, and bioinformatics tools is currently making significant contributions to a better knowledge of the composition and structure of the cereal proteins and their structure-function relationships. Results obtained using mass spectrometry, including characterization of prolamins, investigation of the gluten toxicity for coeliac patients, identification of proteins responsible of cereal allergies, determination of the protein pattern and its modification under environmental or stress effects, investigation of genetically modified varieties by proteomic approaches, are summarized here, to illustrate current trends, analytical troubles and challenges, and suggest possible future perspectives.