Chemistry of Ethanediyl S,S-Acetals. VII. A Stereoselective Synthesis of Allylic Alcohols with cis-Configurated Double Bond

A new high yielding coupling reaction of C-2 monosubstituted 5,6-dihydro-1,4-dithiins with aldehydes is reported. In this way allylic alcohols having the cis-substituted double bond tied up by a sulfur-containing ring can be readily prepared. Subsequent stereoselective sulfur removal then affords allylic alcohols with cis-configurated double bond.     

An analytical strategy for identification of a somatotropin‐like bioactive peptide by ion trap liquid chromatography/electrospray ionization tandem mass spectrometry after immuno‐affinity purification from buffalo serum

The use of growth hormones, such as native and recombinant somatotropins, is forbidden in the European Union (EU), but is legal in the USA. The misuse of recombinant bovine somatotropin in Italy is suspected for enhancing milk production, thanks to its availability on the illegal market. A synthetic bioactive peptide of 27 amino acids derived from bovine somatotropin was successfully tested in France and in southern Italy for scientific purposes, to stimulate milk production, both in cows and buffaloes. This somatotropin‐like peptide (PEP‐ST), suspected for illegal use in southern Italy, was synthesized by linking the 104–113 sequence of bovine somatotropin to the 323–339 sequence of ovalbumin. Herein, a method for detection and identification of the PEP‐ST in buffalo serum is described; our strategy was based on the production of IgG anti‐PEP‐ST, used to synthesize an immuno‐affinity column for peptide purification from buffalo serum, prior to analysis by ion trap liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI‐MS/MS). The immuno‐affinity column was successfully used to purify in a single step the bioactive PEP‐ST from buffalo serum samples spiked at 20, 50 and 200 µg/mL for confirmatory analysis. Ion trap LC/ESI‐MS/MS identification was based on detection of a multi‐charged molecular ion and its characteristic fragmentation pattern. No significant matrix interference was observed, accounting for method specificity. We consider this strategy to be a basic approach that could be improved in the perspective of the official control of illegal use of somatotropin and somatotropin‐like compounds in buffalo breeding. Copyright © 2009 John Wiley & Sons, Ltd.     

Structural properties of some heteroaryl amines. Crystallographic studies on 2-N-(2,4,6-trinitrophenyl)-pyridineamine(I),-4-methylthiazoleamine(II), and-pyrimidineamine(III)

Crystallographic properties of the title compounds are reported and inter- and intra-molecular interactions of the amino group are discussed and related to spectroscopic data. The geometry of the nitrogroups and of the 2-aminoheterocyclic moiety indicate that classical conjugation theory cannot explain the UV/vis spectra. The red shift observed on substituting H by a Me on the 2-amino group is interpreted in terms of internal charge-transfer.     

Regularity properties for Monge transport density and for solutions of some shape optimization problem

In this paper we study the dimension of some measures which are related to the classical Monge's optimal mass transport problem and are solutions of a scalar shape optimization problem. Moreover in the case of maximal dimension we will study the summability of the associate densities. Received: 16 November 2000 / Accepted: 4 December 2000 / Published online: 18 January 2002     

Supported Ru catalysts: a study of the influence of supports, promoters and preparative variables on the catalytic activity and selectivity

The influence of some preparative variables, of the metal loading and of the support on the activity of Ru catalysts for the selective hydrogenation of benzene to cyclohexene has been studied. The reaction has been carried out in a tetraphase reactor (in the presence of an aqueous solution of ZnSO₄) at 423 K and 5 MPa pressure. The effect of hydrogen diffusion on the reaction kinetics and on cyclohexene selectivity was studied. The hydrophilicity of the support was related to the observed selectivity. Hydrogen chemisorption indicates that the catalyst activity is not influenced by the Ru dispersion, but mainly by the weakly chemisorbed species on the catalyst surface. This revised version was published online in August 2006 with corrections to the Cover Date.     

A global Lipschitz continuity result for a domain-dependent Neumann eigenvalue problem for the Laplace operator

Let Ω be an open connected subset of Rⁿ of finite measure for which the Poincaré-Wirtinger inequality holds. We consider the Neumann eigenvalue problem for the Laplace operator in the open subset φ(Ω) of Rⁿ, where φ is a locally Lipschitz continuous homeomorphism of Ω onto φ(Ω). Then, we show Lipschitz-type inequalities for the reciprocals of the eigenvalues delivered by the Rayleigh quotient. Then, we further assume that the imbedding of the Sobolev space W^1,2(Ω) into the space L²(Ω) is compact, and we prove the same type of inequalities for the projections onto the eigenspaces upon variation of φ.