Synthesis, high-performance liquid chromatography-nuclear magnetic resonance characterization and pharmacokinetics in mice of CD271 glucuronide

A transgenic reporter mouse model for in vivo assessment of retinoic acid receptor transcriptional activation

Background: Vitamin A is essential for a wide range of life processes throughout embryogenesis to adult life. With the aim of developing an in vivo model to monitor retinoic acid receptor (RAR) transactivation real-time in intact animals, we generated transgenic mice carrying a luciferase (luc) reporter gene under the control of retinoic acid response elements (RAREs) consisting of three copies of a direct repeat with five spacing nucleotides (DR5). Methods: Transgenic mice carrying a RARE dependent luciferase reporter flanked with insulator sequence were generated by pronuclear injection. RARE dependent luciferase activity was detected by in vivo imaging or in tissue extracts following manipulations with RAR/retinoid X receptor (RXR) agonists, RAR antagonists or in vitamin A deficient mice. Results: We found a strong induction of luciferase activity in a time and dose dependent manner by retinoic acid as well as RAR agonists, but not by the RXR agonist (using n=4-6 per group; 94 mice). In addition, luciferase activity was strongly reduced in vitamin A-deficient mice (n=6-9; 30 mice). These observations confirm that luciferase activity was controlled by RAR activation in the RARE-luc mouse. Luciferase activity was detectable in various organs, with high activity especially in brain and testis, indicating strong retinoid signalling in these tissues. Conclusion: The RARE-luc transgenic mice, which enabled real-time in vivo assessment of RAR activation, will be useful in understanding the normal physiology of vitamin A, the role of retinoid signalling in pathologies as well as to evaluate pharmacological ligands for RARs.

Effective Synthesis of 1β-Acyl Glucuronides by Selective Acylation

[reaction: see text] Acyl glucuronides are vital metabolites for many carboxylic acid containing drugs. We report an efficient new method for the chemical synthesis of these molecules by selective 1beta-acylation of allyl glucuronate with carboxylic acids catalyzed by HATU and then mild deprotection through treatment with Pd(PPh(3))(4) and morpholine. The method is effective for a range of aryl and alkyl carboxylic acids, including important drugs.

LC-NMR-MS in drug discovery

Nuclear magnetic resonance spectroscopy (NMR) is arguably the most versatile analytical platform for complex mixture analysis. Specifically, interfacing liquid chromatography with parallel NMR and mass spectrometry (LC-NMR-MS) gives comprehensive structural data on metabolites of novel drugs in development. Applications in natural product, combinatorial chemistry and drug metabolism studies are reviewed. Microcoil probes and capillary separation methods have enormous potential. Recent innovations to improve NMR detection limits include CryoFlowProbes and on-line solid-phase extraction (LC-SPE-NMR). These state-of-the-art analytical platforms are widely applicable to identifying novel candidate drugs from diverse complex mixtures within a drug discovery strategy.