A simple two steps ytterbium triflate‐catalysed preparation of 2,2‐dimethyl‐2h‐chromenes from salicylaldehydes and 2‐methylpropene

International audienceThe preparation of various 2,2‐dimethyl‐2H‐chromenes was achieved in two steps via an ytterbium triflate‐catalysed reaction between salicylaldehydes, trimethylorthoformate and 2‐methylpropene. From salicylaldehyde, two reaction products were characterised: 4‐methoxy‐2,2‐dimethylchroman and 2‐(1,3‐dimethoxy‐3‐methylbutyl)phenol. The former compound probably results from a Lewis acid‐catalysed [2+4] cycloaddition between the intermediate quinonemethide and 2‐methylpropene whereas the latter may occur via a reaction related to a carbonyl‐ene reaction between the quinonemethide and 2‐methylpropene. Both compounds were subjected to a catalytic acidic treatment leading to 2,2‐dimethyl‐2H‐chromene. Starting from various salicylaldehydes, the scope of this method was investigated

La « Tour de Vésone » à Périgueux (Dordogne) : nouvelle lecture

in : Journée de recherches sur les temples ronds, Bordeaux, 22 novembre 2002International audienc

Synthesis and antimycobacterial evaluation of benzofurobenzopyran analogues

We recently reported that 3,3-dimethyl-3H-benzofuro[3,2,f][1]-benzopyran and its hydrogenated analogue are selective in vitro inhibitors of mycobacterial growth. However, their lack of in vivo activity on a murine model of Mycobacterium tuberculosis infection due to their poor bioavailability led to a structure-activity relationship investigation. We wish to report here the preparation of some structural analogues along with their biological effect on the growth of Mycobacterium smegmatis, M. tuberculosis, as well as on VERO cells for the most active compound

Synthesis and antimycobacterial evaluation of benzofurobenzopyran analogues.: Synthesis and antimycobacterial evaluation of benzofurobenzopyran analogues.

International audienceWe recently reported that 3,3-dimethyl-3H-benzofuro[3,2,f][1]-benzopyran and its hydrogenated analogue are selective in vitro inhibitors of mycobacterial growth. However, their lack of in vivo activity on a murine model of Mycobacterium tuberculosis infection due to their poor bioavailability led to a structure-activity relationship investigation. We wish to report here the preparation of some structural analogues along with their biological effect on the growth of Mycobacterium smegmatis, M. tuberculosis, as well as on VERO cells for the most active compound

Use of penetrating peptides interacting with PP1/PP2A proteins as a general approach for a drug phosphatase technology.

Protein phosphatase types 1 (PP1) and 2A (PP2A) represent two major families of serine/threonine protein phosphatases that have been implicated in the regulation of many cellular processes, including cell growth and apoptosis in mammalian cells. PP1 and PP2A proteins are composed of oligomeric complexes comprising a catalytic structure (PP1c or PP2AC) containing the enzymatic activity and at least one more interacting subunit. The binding of different subunits to a catalytic structure generates a broad variety of holoenzymes. We showed here that casein kinase 2alpha (Ck2alpha) and simian virus 40 small t antigen share a putative common beta-strand structure required for PP2A1 trimeric holoenzyme binding. We have also characterized DPT-sh1, a short basic peptide from Ck2alpha that interacted only in vitro with the PP2A-A subunit and behaves as a nontoxic penetrating shuttle in several cultivated human cell lines and chick embryos. In addition, DPT-sh1 specifically accumulated in human red cells infected with Plasmodium falciparum malaria parasites. We therefore designed bipartite peptides containing DPT-sh1 and PP1- or PP2A-interacting sequences. We found that DPT-5, a DPT-sh1-derived peptide containing a short sequence identified in CD28 antigen, interacts with PP2A-Balpha, and DPT-7, another DPT-sh1-derived peptide containing a short sequence identified in Bad as a PP1 catalytic consensus docking motif, induce apoptosis in cultivated cell lines. These results clearly indicate that the rational design of PP1/PP2A interacting peptides is a pertinent strategy to deregulate intracellular survival pathways

A Blood RNA Signature Detecting Severe Disease in Young Dengue Patients at Hospital Arrival

International audienceand 10 GSK vaccines R&D, Singapore Background. Early detection of severe dengue can improve patient care and survival. To date, no reliable single-gene biomarker exists. We hypothesized that robust multigene signatures exist. Methods. We performed a prospective study on Cambodian dengue patients aged 4 to 22 years. Peripheral blood mononuclear cells (PBMCs) were obtained at hospital admission. We analyzed 42 transcriptomic profiles of patients with secondary dengue infected with dengue serotype 1. Our novel signature discovery approach controls the number of included genes and captures non-linear relationships between transcript concentrations and severity. We evaluated the signature on secondary cases infected with different serotypes using 2 datasets: 22 PBMC samples from additional patients in our cohort and 32 whole blood samples from an independent cohort. Results. We identified an 18-gene signature for detecting severe dengue in patients with secondary infection upon hospital admission with a sensitivity of 0.93 (95% confidence interval [CI], .82-.98), specificity of 0.67 (95% CI, .53-.80), and area under the receiver operating characteristic curve (AUC) of 0.86 (95% CI, .75-.97). At validation, the signature had empirical AUCs of 0.85 (95% CI, .69-1.00) and 0.83 (95% CI, .68-.98) for the PBMCs and whole blood datasets, respectively. Conclusions. The signature could detect severe dengue in secondary-infected patients upon hospital admission. Its genes offer new insights into the pathogenesis of severe dengue

Type I High-IFN Gene Signature in Associated with Higher Essdai at Enrollmment and Follow-up in the Prospective Multicenter Assess Cohort of 395 Patients

International audienc

Type I high-IFN gene signature in associated with higher essdai at enrollment and follow-up in the prospective multicenter assess cohort of 395 patients

International audienc