A regioselective approach toward the synthesis of pharmacologically important quinone-containing heterocyclic systems

An inexpensive and regioselective approach to dihydrothieno[3,2-g]quinoline-4,9-dione is reported. A combination of a mild version of Skraup reaction with a sequential substitution/Michael addition allowed the selective preparation in acceptable yield of a pharmacologically important quinone derivative, previously obtained only in trace and together with the other regioisomer.     

In Silico Identification of Tripeptides as Lead Compounds for the Design of KOR Ligands

The kappa opioid receptor (KOR) represents an attractive target for the development of drugs as potential antidepressants, anxiolytics and analgesics. A robust computational approach may guarantee a reduction in costs in the initial stages of drug discovery, novelty and accurate results. In this work, a virtual screening workflow of a library consisting of ~6 million molecules was set up, with the aim to find potential lead compounds that could manifest activity on the KOR. This in silico study provides a significant contribution in the identification of compounds capable of interacting with a specific molecular target. The main computational techniques adopted in this experimental work include: (i) virtual screening; (ii) drug design and leads optimization; (iii) molecular dynamics. The best hits are tripeptides prepared via solution phase peptide synthesis. These were tested in vivo, revealing a good antinociceptive effect after subcutaneous administration. However, further work is due to delineate their full pharmacological profile, in order to verify the features predicted by the in silico outcomes.     

Stable Peptides Instead of Stapled Peptides: Highly Potent αvβ6‐Selective Integrin Ligands

The αvβ6 integrin binds the RGD‐containing peptide of the foot and mouth disease virus with high selectivity. In this study, the long binding helix of this ligand was downsized to an enzymatically stable cyclic peptide endowed with sub‐nanomolar binding affinity toward the αvβ6 receptor and remarkable selectivity against other integrins. Computational studies were performed to disclose the molecular bases underlying the high binding affinity and receptor subtype selectivity of this peptide. Finally, the utility of the ligand for use in biomedical studies was also demonstrated here.     

β-Fe2O3 nanomaterials from an iron(II) diketonate-diamine complex: a study from molecular precursor to growth process

Iron oxide is a key multi-functional material in many different fields of modern technology. The β-Fe(2)O(3) cubic phase, one of the least studied Fe-O systems, was obtained by Chemical Vapor Deposition (CVD) using for the first time a Fe(II) β-diketonate diamine complex, Fe(hfa)(2)·TMEDA, as the molecular source (hfa = 1,1,1,5,5,5-hexafluoro-2,4-pentanedionate; TMEDA = N,N,N',N'-tetramethylethylenediamine). The strong visible light absorption of β-Fe(2)O(3) deposits highlights their possible functional application in photocatalytic hydrogen production under solar light. A comprehensive investigation on the Fe(ii) complex, performed by a joint experimental-theoretical approach, explains the molecular origin of its excellent thermal behaviour and reveals why this species is a successful precursor for the CVD of iron oxide nanostructures.     

Reference frames in harmonic coordinates: geometric and physical aspects

This work is focused on the geometrical and physical characteristics of the class of reference frames associated to harmonic coordinates. Precisely, we express in relative form the harmonicity conditions and consider the so called ??spatially harmonicity?? of a reference frame in spherical symmetry. The initial data problem is then analyzed in polar coordinates and the obtained results are applied to special cases of exact solutions.     

Esistenza ed unicita’ delle soluzioni di un problema misto per un sistema iperbolico simmetrico con coefficienti discontinui

In this paper we give existence and uniqueness theorems for weak solutions of a mixed initial and boundary value problem with conservative boundary conditions relating to a particular symmetric hyperbolic linear system with discontinuous coefficients. The unicity is proved also for a mixed non linear problem.     

FTIR spectra and structure of new polystyrenes: Syndiotactic polystyrene and poly-para-methyl-styrene

Highly syndiotactic poly(styrene) shows higher crystallinity and a higher melting point than the corresponding isotactic material. Temperature dependent FTIR spectra have been recorded and the structural evolution of the system from the ordered to the amorphous phase has been followed.     

Universal One-Way Light Speed from a Universal Light Speed Over Closed Paths

This paper gives two complete and elementary proofs that if the speed of light over closed paths has a universal value c, then it is possible to synchronize clocks in such a way that the one-way speed of light is c. The first proof is an elementary version of a recent proof. The second provides high precision experimental evidence that it is possible to synchronize clocks in such a way that the one-way speed of light has a universal value. We also discuss an old incomplete proof by Weyl which is important from an historical perspective.     

Desulphurative approaches to penem antibiotics. VI. From penam methyl esters to penem acetonyl esters: A fully conservative conversion

A straightforward conversion of penam methyl esters into penem acetonyl esters entailing incorporation of all the elements of the former into the latter is described.