Chimie

In this work, we have developed two new supported liquid membranes (SLMs) for the recovery of cadmium ions Cd(II) from acidic mediums. To prepare this type of membrane, we have used the PVDF polymer as support, the compounds methyl Cholate (MC), Tri-butyl phosphate (TBP) as carriers, and toluene solvent as the organic phase. We have developed a kinetic model to calculate the macroscopic parameters (permeability P and the initial flux J0) relating to each membrane prepared, and we have also developed a thermodynamic model to determine the microscopic parameters Kass (association constant) and D* (apparent diffusion coefficient) that are specific to the diffusion of the complex (TS) formed between the substrate and the carrier used through the organic phase. The proposed models are verified by the experimental results found, and we have studied the influence of the nature of the carrier, and the initial concentration of the substrate Cadmium ions. Furthermore, these results indicate that the migration of cadmium ions through the organic phase of the SLM, is not a pure diffusion, but this migration corresponds to successive jumps of the substrate from one site to the other of the carrier.

A series of novel 2-[(4-phenylpiperazin-1-yl)methyl]imidazoazines and aza-analogues were prepared and screened at selected dopamine, serotonin, and adrenergic receptor subtypes. 2-Substituted imidazopyridines and pyridazines presented high affinities and selectivities for D4 dopamine receptors. Whereas functional experiments indicated neutral antagonists or weak partial agonist effects for most of the target compounds, the 2-methoxyphenyl substituted 2-piperazinylmethylimidazopyridine 3c (PIP3EA) displayed substantial agonist efficacy in mitogenesis experiments and GTPgammaS binding tests, resulting in EC50 values of 3.0 (46%) and 4.5 nM (57%), respectively. Our D4 agonist 3c induced penile erection in vivo when administered to rats. This effect was inhibited by L-745,870 a D4 selective antagonist, confirming the mechanistic pathway.

Motivated by the widely reported anticancer activity of parthenolides and their derivatives, a series of new substituted parthenolides was efficiently synthesized. Structural modifications were performed at the C-9 and C-13 positions of 9α- and 9β-hydroxyparthenolide, which were isolated from the aerial parts of Anvillea radiata. Twenty-one derivatives were synthesized and evaluated for their in vitro cytotoxic activity against HS-683, SK-MEL-28, A549, and MCF-7 human cancer cell lines using the MTT colorimetric assay. Among the derivatives, seven exhibited excellent activity compared to 5-fluorouracil and etoposide against the four cell lines tested, with IC50 values ranging from 1.1 to 9.4 µM.

ABSTRACT The catalytic acid rearrangement of 9α-hydroxyparthenolide (1), the main constituent of Anvillea radiata, has been studied. Several new sesquiterpene compounds were obtained and their structures were fully elucidated. A mechanism to explain the formation of these compounds is proposed.

Previously unknown N-3-substituted pyrido[1′,2′:1,5]py­razo­lo[3,4-d]pyrimidine derivatives were synthesized by a straightforward four-step synthesis. Starting from a 1-aminopyridinium salt, dimethyl acetylenedicarboxylate condensation followed by a fully regioselective saponification led to a pyrazolo[1,5-a]pyridine monoester as a key intermediate. A Curtius rearrangement directly followed by amine condensation afforded a urea library. A final pyrimidine ring closure resulted in achievement of the heterocyclic construction. This straightforward strategy provides an efficient method to easily access a library of rare tricyclic scaffolds and highly valuable derivatives.

ABSTRACT The first efficient synthesis of various 1,4-disubstituted pyrido[1′,2′:1,5]pyrazolo[3,4-d]pyridazines is reported. The reactivity toward chlorine release at the C-1 and C-4 positions was investigated. SNAr and palladium-catalysed cross-coupling reactions were carried out, and conditions were optimised for each procedure. 1,4-Bis(het)aryl derivatives were obtained under a Suzuki cross-coupling procedure whereas SNAr substitution was achieved mainly at C-1 in preference to C-4. The monosubstituted C-4 morpholino derivative was used as a starting material to provide dissymmetrical 1,4-diaminated or 1-(het)aryl-4-morpholino products.