Sonolysis of levodopa and paracetamol in aqueous solutions

Pharmaceutical products are often present in wastewater treatment effluents, rivers, lakes and, more rarely, in groundwater. The advanced oxidation methods, like ultrasound, find a promising future in the area of wastewater treatment. The aim of this paper is to evaluate the influence of several parameters of the ultrasound process on the degradation of paracetamol, a widely used non-steroidal anti-inflammatory recalcitrant drug found in water and levodopa, the most frequently prescribed drug for the treatment of Parkinson disease. Experiments were carried out at 574, 860 and 1134 kHz of ultrasonic frequency with horn-type sonicator and actual power values of 9, 17, 22 and 32 W at 20 °C. Initial concentrations of 25, 50, 100 and 150 mg L^?1 of both products were used. Treatment efficiency was assessed following changes in pharmaceuticals concentration and chemical oxygen demand.The sonochemical degradation of both products follows a pseudo-first-order reaction kinetics. Complete removal of pharmaceuticals was achieved in some cases but some dissolved organic carbon remains in solution showing that long lived intermediates were recalcitrant to ultrasound irradiation. Pollutants conversion and COD removal were found to decrease with increasing the initial solute concentration and decreasing power. The best results were obtained with 574 kHz frequency. Investigations using 1-butanol as radical scavenger and H₂O₂ as promoter revealed that pollutants degradation proceeds principally through radical reactions, although some differences were observed between both molecules. Addition of H₂O₂ had a positive effect on degradation rate, but the optimum concentration of hydrogen peroxide depends on the pollutant.     

Neighbouring effect in the course of the ozonolysis of a hindered bornene derivative

In the course of the ozonolysis of the bicyclo[2.2.1]heptene anhydride 1, the three bis-lactones 3-5 have been obtained (the structures were confirmed by X-ray crystallographic analysis).     

Wagner-Meerwein rearrangement in the course of the ozonolysis of a bornene derivative

The ozonolysis of the bicyclo[2.2.1]heptene derivative 1 or 2 gave the octaline derivative 6 (the structure was confirmed by X-ray crystallographic analysis) or 7. The exo-addition of ozone to the double bond of 1 or 2 was followed by the fragmentation in carbonyl oxide and aldehyde. Then, the strong electrophilic character of the carbonyl oxide induces an unexpected Wagner-Meerwein rearrangement to give zwitterion 4. Finally, a fragmentation reaction with elimination of dioxygen gave the tetrasubstituted C-C double bonds of 6 or 7.     

Hopf algebras of primitive Lie pseudogroups and Hopf cyclic cohomology

We associate to each infinite primitive Lie pseudogroup a Hopf algebra of ‘transverse symmetries,’ by refining a procedure due to Connes and the first author in the case of the general pseudogroup. The affiliated Hopf algebra can be viewed as a ‘quantum group’ counterpart of the infinite-dimensional primitive Lie algebra of the pseudogroup. It is first constructed via its action on the étale groupoid associated to the pseudogroup, and then realized as a bicrossed product of a universal enveloping algebra by a Hopf algebra of regular functions on a formal group. The bicrossed product structure allows to express its Hopf cyclic cohomology in terms of a bicocyclic bicomplex analogous to the Chevalley-Eilenberg complex. As an application, we compute the relative Hopf cyclic cohomology modulo the linear isotropy for the Hopf algebra of the general pseudogroup, and find explicit cocycle representatives for the universal Chern classes in Hopf cyclic cohomology. As another application, we determine all Hopf cyclic cohomology groups for the Hopf algebra associated to the pseudogroup of local diffeomorphisms of the line.     

Cyclic and ruled Lagrangian surfaces in Euclidean four space

We study those Lagrangian surfaces in complex Euclidean space which are foliated by circles or by straight lines. The former, which we call cyclic, come in three types, each one being described by means of, respectively, a planar curve, a Legendrian curve in the 3-sphere or a Legendrian curve in the anti-de Sitter 3-space. We describe ruled Lagrangian surfaces and characterize the cyclic and ruled Lagrangian surfaces which are solutions to the self-similar equation of the Mean Curvature Flow. Finally, we give a partial result in the case of Hamiltonian stationary cyclic surfaces.     

Quantification of asenapine and three metabolites in human plasma using liquid chromatography-tandem mass spectrometry with automated solid-phase extraction: application to a phase I clinical trial with asenapine in healthy male subjects

The development and validation of methods for determining concentrations of the antipsychotic drug asenapine (ASE) and three of its metabolites [N-desmethylasenapine (DMA), asenapine-N(+) -glucuronide (ASG) and 11-O-sulfate-asenapine (OSA)] in human plasma using LC-MS/MS with automated solid-phase extraction is described. The three assessment methods in human plasma were found to be acceptable for quantification in the ranges 0.0250-20.0 ng/mL (ASE), 0.0500-20.0 ng/mL (DMA and OSA) and 0.250-50.0 ng/mL (ASG).