Substituted 1-amino-cyclopentenes from 2,3-diamino-1,3-butadienes and nitroalkenes

2,3-Diamino-1,3-butadienes (1) reacted with β-nitrostyiene or nitroethene to afford a mixture ofisomeric 1,5-diaminoo-5-methyl-4-nitro-cyclopentenes (3 and 4). The configuration of the main isomers (3) was established by X-ray diffraction analysis which also revealed the great steric crowding of this molecule. The conformation of the cyclopentene ring in 3 in the solid state is also discussed. The enamines (3 and 4) were hydrolyzed to the corresponding aminoketones (5 and 6) which, on reduction, gave the same diaminoketone (7).     

HPLC and NMR analysis of the phenyl-ethanoid glycosides pattern of Verbascum thapsus L. cultivated in the Etnean area

In this work the HPLC and NMR analysis of the phenyl-ethanoid glycosides (PhGs) pattern of a cultivated exemplar of Verbascum thapsus L. (Scrophulariaceae) from the Etnean area (Sicily, Italy) was performed in order to verify their possible presence. Wild V. thapsus is well-known in ethnopharmacology due to the several beneficial effects that it is able to exert and which are primarily due to these compounds. So, it’s extremely important that also cultivated exemplars of this species biosynthesize them in order to maintain their pharmacological properties. This study revealed the presence of seven PhGs in an unusual novel pattern. Thus, this exemplar is a very good potential source of this class of natural products and may be employed for several beneficial ethnopharmacological purposes.     

High‐performance liquid chromatography/electrospray ionization tandem mass spectrometric investigation of stilbenoids in cell cultures of Vitis vinifera L., cv. Malvasia

Cell suspension cultures of Vitis vinifera L., particularly after elicitation, have shown the ability to biosynthesize several stilbenoids. In this work the application of specific tandem mass spectrometry (MS/MS) experiments and the integration with data from UV‐vis spectra, available only for the main compounds of the extract, allowed the detection of over 20 different stilbenoids. Up to eight monoglicosides, both monomers and dimers, a high number of dimer forms (up to 17), belonging to the group of viniferins and to their oxidized derivatives, were identified in the extract of Malvasia cell cultures. Moreover, the selectivity and sensitivity of the method allowed detection also of a few cis derivatives (up to 3) present in very low concentrations and presumably produced by the light exposure during treatment of the sample. To the best of the authors' knowledge, there are no literature data on MS/MS experiments targeted to simultaneously study monomeric and dimeric stilbenoids, both as free and glycosilated forms, in a complex mixture from V. vinifera cell suspension cultures. Copyright © 2010 John Wiley & Sons, Ltd.     

Equilibrium Solution to the Inelastic Boltzmann Equation Driven by a Particle Bath

We show the existence of smooth stationary solutions for the inelastic Boltzmann equation under the thermalization induced by a host medium with a fixed distribution. This is achieved by controlling the L ^p -norms, the moments and the regularity of the solutions to the Cauchy problem together with arguments related to a dynamical proof for the existence of stationary states.     

Surface characterization of a decarburized and nitrided steel.

This article describes the effects of surface controlled decarburization on the structure of a nitrided steel. Samples of quenched and tempered 40CrMo4 steel were decarburized by air heat treatment (800-900 degrees C) at different depths and submitted to gaseous nitriding. The microstructure of surface layers after decarburization and nitriding were investigated by optical (OM) and scanning electron microscopy (SEM). The nitrogen and carbon profiles in the diffusion layers were determined by a scanning electron microscope equipped with a wavelength dispersive spectrometer (EPMA-WDS). The effect of nitriding was determined by microhardness measurements. The increasing of time and temperature of decarburization slightly affect the surface hardness values, while case hardness depths decrease. In all the specimens, the nitriding depth, as determined by the WDS nitrogen profile, is larger than the one determined by the hardness profile.     

Fluid-dynamic equations for reacting gas mixtures

Starting from the Grad 13-moment equations for a bimolecular chemical reaction, Navier-Stokes-type equations are derived by asymptotic procedure in the limit of small mean paths. Two physical situations of slow and fast reactions, with their different hydrodynamic variables and conservation equations, are considered separately, yielding different limiting results.This work was performed in the frame of the activities sponsored by MIUR (Project Mathematical Problems of Kinetic Theories), by INdAM, by GNFM, by the University of Parma (Italy), and by the European TMR Network Hyperbolic and Kinetic Equations: Asymptotics, Numerics, Analysis.This revised version was published online in April 2005 with a corrected issue number.     

Phenylpropanoid glycosides in Italian Orobanche spp., sect. Orobanche

We studied the occurrence of phenylpropanoid glycosides (PhG) in five species of the genus Orobanche L., collected in the Latium region of Italy. The presence of orobanchoside and verbascoside in all four species confirms that these PhGs are taxonomic markers of the genus. The results suggest that O. gracilis form. citrina could be a diverse entity.     

A comparative chemotaxonomic study on Vinca sardoa steam and Vinca difformis pourret

The phytochemical analysis of iridoidic fraction of the aerial parts of Vinca sardoa and Vinca difformis, gave the identification of loganic acid in V. difformis as unique iridoid glucoside, while loganin is also present in V. sardoa. The two taxa highly differ in alkaloids, so the chemotaxonomic classification in two different species is supported.