Jean Dessolin

Synthesis and Biological Activity of Phosphonate Analogues and Geometric Isomers of the Highly Potent Phosphoantigen (E)-1-Hydroxy-2-methylbut-2-enyl 4-Diphosphate

Gammadelta-T-lymphocytes contribute to innate immunity and are selectively activated by nonpeptide phosphorylated molecules (so-called phosphoantigens) produced by organisms responsible for causing a broad range of infectious diseases. gammadelta-T-cells are also activated by synthetic phosphoantigens and are cytotoxic to tumor cells. Here we report the synthesis, NMR characterization, and comparative biological evaluation of new pyrophosphate, phosphonate, and pyrophosphonate monoesters whose structures correspond to isosteric analogues and stereoisomers of the highly potent isoprenoid metabolite ( E)-1-hydroxy-2-methylbut-2-enyl 4-diphosphate called HDMAPP (hydroxy-dimethyl-allyl pyrophosphate). Both pyrophosphate and pyrophosphonate series elicit promising gammadelta-T-cell stimulatory responses in vitro, the pyrophosphonate ester (C-HDMAPP) being by far more stable than its parent pyrophosphate ester (HDMAPP) with improved ADMET properties and a similar pharmacodynamic profile based on in vivo studies in nonhuman primate. In both series, we found that E-stereoisomers are the most active derivatives and that Z-stereoisomers show very marginal bioactivity levels. These results indicate that the use of bioisosteric analogues of HDMAPP may represent promising new leads for immunotherapy.

N-(3-(2-amino-6,6-difluoro-4,4a,5,6,7,7a-hexahydro-cyclopenta[e][1,3]oxazin-4-yl)-phenyl)-amides as BACE1 inhibitors: a patent evaluation of WO2013041499

A new series of oxazin amides have been synthesized from isoxazoles using a reaction to increase the heterocyclic ring size and were evaluated as BACE1 inhibitors. The innovative compounds were able to diminish amyloid-β peptide concentration in cell and proved to be selective toward peptidases from the same family. Further studies on the toxicity of this series showed that these new molecules were not recognized by P-glycoprotein and that they were unsusceptible to rapid metabolization by cytochrome P450 or glutathione conjugation. These results indicate that such compounds could be useful in developing drugs to fight Alzheimers disease and that this novel oxazin scaffold should be considered as a starting point to tackle this pathology.

New Polyazamacrocycle-Nucleoside Conjugates: Synthesis, Anti-HIV Evaluation and Interaction with CXCR-4 Coreceptor

We report the synthesis of new conjugates that incorporate in their structure bis-tetraazamacrocycle coupled with AZT via enzymolabile bond. Two series of bis-polyazamacrocycles-AZT conjugates were designed, synthesized and evaluated for their antiviral effect in vitro as well as their capability to bind to CXCR-4 coreceptor.