Vincent Luzet

Novel tacrine-grafted Ugi adducts as multipotent anti-Alzheimer drugs: a synthetic renewal in tacrine-ferulic acid hybrids

Herein we describe the design, multicomponent synthesis, and biological, molecular modeling and ADMET studies, as well as in vitro PAMPA‐blood–brain barrier (BBB) analysis of new tacrine–ferulic acid hybrids (TFAHs). We identified (E)‐3‐(hydroxy‐3‐methoxyphenyl)‐N‐{8[(7‐methoxy‐1,2,3,4‐tetrahydroacridin‐9‐yl)amino]octyl}‐N‐[2‐(naphthalen‐2‐ylamino)2‐oxoethyl]acrylamide (TFAH 10 n) as a particularly interesting multipotent compound that shows moderate and completely selective inhibition of human butyrylcholinesterase (IC50=68.2 nM), strong antioxidant activity (4.29 equiv trolox in an oxygen radical absorbance capacity (ORAC) assay), and good β‐amyloid (Aβ) anti‐aggregation properties (65.6 % at 1:1 ratio); moreover, it is able to permeate central nervous system (CNS) tissues, as determined by PAMPA‐BBB assay. Notably, even when tested at very high concentrations, TFAH 10 n easily surpasses the other TFAHs in hepatotoxicity profiling (59.4 % cell viability at 1000 μM), affording good neuroprotection against toxic insults such as Aβ1–40, Aβ1–42, H2O2, and oligomycin A/rotenone on SH‐SY5Y cells, at 1 μM. The results reported herein support the development of new multipotent TFAH derivatives as potential drugs for the treatment of Alzheimer′s disease.

Noncovalent bicomponent self-assemblies on a silicon surface.

Two-dimensional supramolecular multicomponent networks on surfaces are of major interest for the building of highly ordered functional materials with nanometer-sized features especially designed for applications in nanoelectronics, energy storage, sensors, etc. If such molecular edifices have been previously built on noble metals or HOPG surfaces, we have successfully realized a 2D open supramolecular framework on a silicon adatom-based surface under ultrahigh vacuum with thermal stability up to 400 K by combining molecule-molecule and molecule-silicon substrate interactions. One of these robust open networks was further used to control both the growth and the periodicity of the first bicomponent arrays without forming any covalent bond with a silicon surface. Our strategy allows the formation of a well-controlled long-range periodic array of single fullerenes by site-specificity inclusion into a bicomponent supramolecular network.

Quinolone-benzylpiperidine derivatives as novel acetylcholinesterase inhibitor and antioxidant hybrids for Alzheimer disease.

Design, synthesis and evaluation of new acetylcholinesterase inhibitors by combining quinolinecarboxamide to a benzylpiperidine moiety are described. Then, a series of hybrids have been developed by introducing radical scavengers. Molecular modeling was performed and structure activity relationships are discussed. Among the series, most potent compounds show effective AchE inhibitions, high selectivities over butyrylcholinesterase and high radical scavenging activities. On the basis of this work, the ability of quinolone derivatives to serve in the design of N-benzylpiperidine linked multipotent molecules for the treatment of Alzheimer Disease has been established.

Dipole-driven self-organization of zwitterionic molecules on alkali halide surfaces.

Summary We investigated the adsorption of 4-methoxy-4′-(3-sulfonatopropyl)stilbazolium (MSPS) on different ionic (001) crystal surfaces by means of noncontact atomic force microscopy. MSPS is a zwitterionic molecule with a strong electric dipole moment. When deposited onto the substrates at room temperature, MSPS diffuses to step edges and defect sites and forms disordered assemblies of molecules. Subsequent annealing induces two different processes: First, at high coverage, the molecules assemble into a well-organized quadratic lattice, which is perfectly aligned with the <110> directions of the substrate surface (i.e., rows of equal charges) and which produces a Moiré pattern due to coincidences with the substrate lattice constant. Second, at low coverage, we observe step edges decorated with MSPS molecules that run along the <110> direction. These polar steps most probably minimize the surface energy as they counterbalance the molecular dipole by presenting oppositely charged ions on the rearranged step edge.

Self-Assembly of a Halogenated Molecule on Oxide-Passivated Cu(110)

The supramolecular self-assembly of brominated molecules was investigated and compared on Cu(110) and Cu(110)-O(2×1) surfaces under ultrahigh vacuum. By using scanning tunnelling microscopy, we show that brominated molecules form a disordered structure on Cu(110), whereas a well-ordered supramolecular network is observed on the Cu(110)-O(2×1) surface. The different adsorption behaviors of these two surfaces are described in terms of weakened molecule-substrate interactions on Cu(110)-O(2×1) as opposed to bare Cu(110). The effect of oxygen-passivation is to suppress debromination and it can be a convenient approach for investigating other self-assembly processes on copper-based substrates.

Reversible Single Molecular Switch Operating at 300 K on a Surface

A single 4-pyridylazobenzene molecule is observed at room temperature on a Si(111)-B surface by using scanning tunnel microscopy. The reversible conformational switching of this molecule is induced by tunneling electrons and observed at room temperature. This process is based on an intramolecular rotation of a single phenyl group without isomerization of the N=N double bond.

Synthesis and Biological Assessment of Racemic Benzochromenopyrimidinimines as Antioxidant, Cholinesterase, and Aβ1−42 Aggregation Inhibitors for Alzheimer's Disease Therapy

Given the complex nature of Alzheimer′s disease (AD), compounds that are able to simultaneously address two or more AD‐associated targets show greater promise for development into drugs for AD therapy. Herein we report an efficient two‐step synthesis and biological evaluation of new racemic benzochromene derivatives as antioxidants, inhibitors of cholinesterase and β‐amyloid (Aβ1−42) aggregation. Based on the results of the primary screening, we identified 15‐(3‐methoxyphenyl)‐9,11,12,15‐tetrahydro‐10H,14H‐benzo[5,6]chromeno[2,3‐d]pyrido[1,2‐a]pyrimidin‐14‐imine (3 e) and 16‐(3‐methoxyphenyl)‐9,10,11,12,13,16‐hexahydro‐15H‐benzo[5′,6′]chromeno[2′,3′:4,5]pyrimido[1,2‐a]azepin‐15‐imine (3 f) as new potential multitarget‐directed ligands for AD therapy. Further in‐depth biological analysis showed that compound 3 f is a good human acetylcholinesterase inhibitor [IC50=(0.36±0.02) μm], has strong antioxidant activity (3.61 μmol Trolox equivalents), and moderate Aβ1−42 antiaggregating power (40.3 %).

Novel aminotetrazole derivatives as selective STAT3 non-peptide inhibitors

The development of inhibitors blocking STAT3 transcriptional activity is a promising therapeutic approach against cancer and inflammatory diseases. In this context, the selectivity of inhibitors against the STAT1 transcription factor is crucial as STAT3 and STAT1 play opposite roles in the apoptosis of tumor cells and polarization of the immune response. A structure-based virtual screening followed by a luciferase-containing promoter assay on STAT3 and STAT1 signaling were used to identify a selective STAT3 inhibitor. An important role of the aminotetrazole group in modulating STAT3 and STAT1 inhibitory activities has been established. Optimization of the hit compound leads to 23. This compound inhibits growth and survival of cells with STAT3 signaling pathway while displaying a minimal effect on STAT1 signaling. Moreover, it prevents lymphocyte T polarization into Th17 and Treg without affecting their differentiation into Th1 lymphocyte.

Synthesis, regioselectivity, and DFT analysis of new antioxidant pyrazolo[4,3-c]quinoline-3,4-diones

Abstract The condensation of hydrazine, N-methylhydrazine, and N-phenylhydrazine with ethyl 4-chloro-2-oxo-1,2-dihydroquinoline-3-carboxylate derivatives has been investigated. As a result, 12 new antioxidant pyrazolo[4,3-c]quinolin-3,4-diones were obtained with good to high yields. When two cross-products could be possible, only one isomer bearing the methyl or the phenyl group at the N1 position is isolated and unequivocally characterized using 1D and 2D NMR techniques, FT-IR, and combustion analyses. DFT analysis of the reaction mechanism was carried out in the Pearson’s hard soft acid base framework, confirming the assigned structure to the observed pyrazolo[4,3-c]quinolin-3,4-diones. These calculations indicate a favored kinetic control for the synthesized pyrazolo[4,3-c]quinolin-3,4-diones compared to its possible regioisomer. Graphical abstract