Mark Wrona

Discovery of 4-[1-[([1-[4-(trifluoromethyl)benzyl]-1H-indol-7-yl]carbonyl)amino]cyclopropyl]benzoic acid (MF-766), a highly potent and selective EP4 antagonist for treating inflammatory pain.

The discovery of a highly potent and selective EP(4) antagonist MF-766 is discussed. This N-benzyl indole derivative exhibits good pharmacokinetic profile and unprecedented in vivo potency in the rat AIA model.

The discovery of 4-{1-[({2,5-dimethyl-4-[4-(trifluoromethyl)benzyl]-3-thienyl}carbonyl)amino]cyclopropyl}benzoic acid (MK-2894), a potent and selective prostaglandin E2 subtype 4 receptor antagonist.

The discovery of highly potent and selective second generation EP(4) antagonist MK-2894 (34d) is discussed. This compound exhibits favorable pharmacokinetic profile in a number of preclinical species and potent anti-inflammatory activity in several animal models of pain/inflammation. It also shows favorable GI tolerability profile in rats when compared to traditional NSAID indomethacin.

Structure–activity relationships and pharmacokinetic parameters of quinoline acylsulfonamides as potent and selective antagonists of the EP4 receptor

A new series of EP(4) antagonists based on a quinoline acylsulfonamide scaffold have been identified as part of our on-going efforts to develop treatments for chronic inflammation. These compounds show subnanomolar intrinsic binding potency towards the EP(4) receptor, and excellent selectivity towards other prostanoid receptors. Acceptable pharmacokinetic profiles have also been demonstrated across a series of preclinical species.

A novel series of potent and selective EP4 receptor ligands: Facile modulation of agonism and antagonism

A novel series of EP(4) ligands, based on a benzyl indoline scaffold, has been discovered. It was found that agonism and antagonism in this series can be easily modulated by minor modifications on the benzyl group. The pharmacokinetic, metabolic and pharmacological profiles of these compounds was explored. It was found that these compounds show good pharmacokinetics in rat and are efficacious in pre-clinical models of pain and inflammation.

Integration of microfluidic LC with HRMS for the analysis of analytes in biofluids: past, present and future

Capillary LC (cLC) coupled to MS has the potential to improve detection limits, address limited sample volumes and allow multiple analyses from one sample. This is particularly attractive in areas where ultrahigh assay sensitivity, low limits of detection and small sample volumes are becoming commonplace. However, implementation of cLC-MS in the bioanalytical-drug metabolism area had been hampered by the lack of commercial instrumentation and the need for experts to operate the system. Recent advances in microfabricated devices such as chip-cube and ion-key technologies offer the potential for true implementation of cLC in the modern laboratory including the benefits of the combination of this type of separation with high-resolution MS.

Naphthalene/quinoline amides and sulfonylureas as potent and selective antagonists of the EP4 receptor.

Two new series of EP(4) antagonists based on naphthalene/quinoline scaffolds have been identified as part of our on-going efforts to develop treatments for inflammatory pain. One series contains an acidic sulfonylurea pharmacophore, whereas the other is a neutral amide. Both series show subnanomolar intrinsic binding potency towards the EP(4) receptor, and excellent selectivity towards other prostanoid receptors. While the amide series generally displays poor pharmacokinetic parameters, the sulfonylureas exhibit greatly improved profile. MF-592, the optimal compound from the sulfonylurea series, has a desirable overall preclinical profile that suggests it is suitable for further development.

Coupling of UHPLC with fast fraction collection–microplate scintillation counting and MS for radiolabeled metabolite profiling

BACKGROUND To further expand the use of fraction collection (FC)-microplate scintillation counting (MSC) in detecting trace amount of radioactivity in absorption, distribution, metabolism and excretion (ADME) studies and improve the resolution of UHPLC-FC-MSC, we report the coupling of UHPLC with MS and faster FC (1.2 s/fraction) followed by MSC using 384-deep-well LumaPlate™ (PerkinElmer, MA, USA) for profiling of radiolabeled metabolites in plasma, urine, bile and feces. RESULTS Collection of 1.2 s/well clearly improved the resolution of the reconstructed radiochromatograms and, at the same time, provided sufficient detection sensitivity that allowed for more accurate integration of peaks, which is required for radiolabeled ADME studies. The introduction of a reversed gradient as a make-up solvent mixture ensured more uniform drops collected in each well, with resolution maintained throughout the UHPLC run. Less sample injection and more frequent FC resulted in less quenching by matrix and accurate integration of peak. CONCLUSION UHPLC-FC-MSC-MS is suitable for metabolite profiling in ADME studies and offers higher resolution, higher sensitivity, shorter LC running time, reduced matrix effect and more environmentally friendly experiments compared with conventional online flow scintillation analysis.

USING ion mobility LC–MS and LC–MS/MS to resolve and identify isobaric glucuronide metabolites

Common metabolic pathways often give rise to multiple instances of isobaric metabolites such as multiple mono-hydroxylations and dihydroxylations and common phase II conjugations, such as glucuronidation. LC-MS analysis of metabolic pathways for drugs requires accurate detection and identification of species with similar RT’s and spectral profiles. Modern chromatography (and mass spectrometry) is sufficient in many cases to track and resolve these peaks, however tracking and identifying isobaric species remain problematic. Ensuring closely eluting species have not chromatographically shifted requires standard addition or co-mixing of matrix and true isobaric coelutions may go undetected with conventional LC-MS approaches as these rely solely on discrimination using precursor mass. Furthermore, the MS/MS patterns from related compounds are often extremely similar.