Time filter

Source Type

Saint-Grégoire, France

Jacolot M.,University of Rennes 1 | Jean M.,University of Rennes 1 | Levoin N.,Bioprojet Biotech | Van De Weghe P.,University of Rennes 1
Organic Letters | Year: 2012

We report a TMSI-promoted Prins cyclization reaction with ketones as carbonyl partners to prepare polysubstituted chiral spirotetrahydropyrans. In the presence of racemic 2-methylcyclohexanone a dynamic kinetic resolution occurred affording one stereoisomer. The observed enantiospecificity has been rationalized by DFT calculation. © 2011 American Chemical Society.

Wicek M.,Jagiellonian University | Kottke T.,Goethe University Frankfurt | Ligneau X.,Bioprojet Biotech | Schunack W.,Free University of Berlin | And 4 more authors.
Bioorganic and Medicinal Chemistry | Year: 2011

Previous studies have shown that several imidazole derivatives posses affinity to histamine H3 and H4 receptors. Continuing our study on structural requirements responsible for affinity and selectivity for H3/H4 receptor subtypes, two series of 3-(1H-imidazol-4-yl)propyl carbamates were prepared: a series of unsaturated alkyl derivatives (1-9) and a series possessing a cycloalkyl group different distances to the carbamate moiety (10-13). The compounds were tested for their affinities at the human histamine H3 receptor, stably expressed in CHO-K1 cells. Compounds 1, 2, 5-7, 10-13 were investigated for their affinities at the human histamine H4 receptor co-expressed with Gαi2 and Gβ1γ2 subunits in Sf9 cells. To expand the pharmacological profile, compounds were further tested for their H3 receptor antagonist activity on guinea pig ileum and in vivo after oral administration to mice. All tested compounds exhibited good affinity for the human histamine H3 receptor with Ki values in the range from 14 to 194 nM. All compounds were active in vivo after peroral administration (p.o.) to Swiss mice, thus demonstrating their ability to cross the blood-brain barrier. The most potent H3 receptor ligand of these series was compound 5, 3-(1H-imidazol-4-yl)propyl pent-4-enylcarbamate with the highest affinity (Ki = 14 nM). Additionally, compound 3 showed remarkable central nervous system (CNS) H3R activity, increasing the Nτ-methylhistamine levels in mice with an ED 50 value of 0.55 mg/kg, p.o. evidencing therefore, a twofold increase of inverse agonist/antagonist potency compared to the reference inverse agonist/antagonist thioperamide. In this study, the imidazole propyloxy carbamate moiety was kept constant. The different lipophilic moieties connected to the carbamate functionality in the eastern part of the molecule had a range of influences on the human H4 receptor affinity (154-1326 nM). © 2011 Elsevier Ltd. All rights reserved.

Robert P.,Bioprojet Biotech | Denis E.,Bioprojet Biotech | Duvauchelle T.,Bioprojet Pharma
European Journal of Clinical Pharmacology | Year: 2016

Objective: The objective of the present study was to compare the effects of pitolisant on QTcF interval in a single ascending dose (SAD) study and a thorough QT (TQT) study. Methods: The SAD study at three dose levels of pitolisant enrolled 24 males and the TQT study at two dose levels 25 males. Both studies intensively monitored ECGs and pitolisant exposure. Effect on QTcF interval was analysed by Intersection Union Test (IUT) and by exposure-response (ER) analysis. Results from the two studies were compared. Results: In both studies, moxifloxacin effect established assay sensitivity. IUT analysis revealed comparable pitolisant-induced maximum mean (90 % confidence interval (CI)) placebo-corrected increase from baseline (ΔΔQTcF) in both the studies, being 13.3 (8.1; 18.5) ms at 200-mg and 9.9 (4.7; 15.1) ms at 240-mg doses in SAD study and 5.27 (2.35; 8.20) ms at 120-mg dose in TQT study. ER analysis revealed that ER slopes in SAD and TQT studies were comparable and significantly positive (0.031 vs 0.027 ms/ng/mL, respectively). At geometric mean concentrations, bootstrap predicted ΔΔQTcF (90 % CI) were 9.23 (4.68; 14.4) ms at 279 ng/mL (240-mg dose) in the SAD study and 4.97 (3.42; 8.19) ms at 156 ng/mL (120-mg dose) in the TQT study. Conclusion: Pitolisant lacked an effect of regulatory concern on QTc interval in both the studies, however analysed, suggesting that the results from the SAD study could have mitigated the need for a TQT study. Our findings add to the growing evidence that intensive ECG monitoring in early phase clinical studies can replace a TQT study. © 2016 Springer-Verlag Berlin Heidelberg.

Duvauchelle T.,Bioprojet Pharma | Robert P.,Bioprojet Biotech | Denis E.,Bioprojet Biotech
European Journal of Clinical Pharmacology | Year: 2015

Objective: To compare the effect of moxifloxacin as a positive control in a single ascending dose (SAD) study with that in a thorough QT (TQT) study. Methods: Moxifloxacin was used as a positive control in a SAD study and a TQT study during the evaluation of the QT liability of a new drug. The SAD study had enrolled 24 males and the TQT study 25 males. Both studies intensively monitored electrocardiograms (ECGs) and pharmacokinetic sampling. Effect of moxifloxacin on QTc interval was analysed in each study by intersection union test (IUT) and by exposure-response (ER) analysis and the results compared. Cost-effectiveness of this approach was computed. Results: Analysis by IUT revealed that the maximum mean (90 % confidence interval (CI)) placebo-corrected change from baseline (ΔΔQTcF) in the SAD study and the TQT study were remarkably similar (10.7 (6.5; 14.9) ms vs. 9.09 (6.20; 11.98) ms, respectively). In both studies, assay sensitivity was established by the 90 % lower bound exceeding 5 ms. ER analysis revealed the slopes in both studies to be significantly different from zero and comparable. Bootstrap-predicted effects of moxifloxacin at geometric mean concentrations of ~3000 ng/mL were 8.19 (90 % CI 5.86; 10.7) ms in the SAD study and 7.33 (90 % CI 5.69; 9.70) ms in the TQT study. Conclusion: Moxifloxacin can be integrated effectively in a SAD study to establish assay sensitivity, and a TQT study may be replaced by a SAD study which has the required assay sensitivity. Further experience is warranted to verify this conclusion. © 2015 Springer-Verlag Berlin Heidelberg.

Croyal M.,Bioprojet Biotech | Dauvilliers Y.,Montpellier University Hospital Center | Labeeuw O.,Bioprojet Biotech | Capet M.,Bioprojet Biotech | And 2 more authors.
Analytical Biochemistry | Year: 2011

An ultra-performance liquid chromatography tandem mass spectrometry (UPLC™-MS/MS) assay was developed for the simultaneous analysis of histamine, its major metabolite tele-methylhistamine, and an internal standard (N-tele-(R)-α-dimethylhistamine) from human cerebrospinal fluid (CSF) samples. The method involves derivatization of primary amines with 4-bromobenzenesulfonyl chloride and subsequent analysis by reversed phase liquid chromatography with mass spectrometry detection and positive electrospray ionization. The separation of derivatized biogenic amines was achieved within 3.5 min on an Acquity® BEH C18 column by elution with a linear gradient of acetonitrile/water/formic acid (0.1%). The assay was linear in the concentration range of 50-5000 pM for each amine (5.5-555 pg/ml for histamine and 6.25-625 pg/ml for tele-methylhistamine). For repeatability and precision determination, coefficients of variation (CVs) were less than 11.0% over the tested concentration ranges, within acceptance criteria. Thus, the developed method provides the rapid, easy, highly sensitive, and selective requirement to quantify these amines in human CSF. No significant difference was found in the mean ± standard error levels of these amines between a group of narcoleptic patients (histamine = 392 ± 64 pM, tele-methylhistamine = 2431 ± 461 pM, n = 7) and of neurological control subjects (histamine = 402 ± 72 pM, tele-methylhistamine = 2209 ± 463 pM, n = 32). © 2010 Elsevier Inc. All rights reserved.

Discover hidden collaborations