ABSTRACT
Conceptual design and modification of urea moiety in chemotype PF-3845/04457845, the bench marking irreversible inhibitor of fatty acid amide hydrolase (FAAH), led to discovery of a novel nicotinamide-based lead 12a having reversible mechanism of action. Focused SAR around the pyridine heterocycle (Ar) in 12a (Tables 1 and 2) resulted into four shortlisted compounds, (-)-12a, (-)-12i, (-)-12l-m. The required (-)-enantiomers were obtained via diastereomeric resolution of a novel chiral dissymmetric intermediate 15. Based on comparative profile of FAAH potency, metabolic stability in liver microsome, liability of inhibiting major hCYP450 isoforms, rat PK, and brain penetration ability, two SAR optimized compounds, (-)-12l and (-)-12m, were selected for efficacy study in rat model of chemotherapy-induced peripheral neuropathy (CIPN). Both the compounds exhibited dose related antihyperalgesic effects, when treated with 3-30â¯mg/kg po for 7â¯days. The effects at 30â¯mg/kg are comparable to that of PF-04457845 (10â¯mg/kg) and Tramadol (40â¯mg/kg).
Subject(s)
Amidohydrolases/antagonists & inhibitors , Drug Discovery , Enzyme Inhibitors/pharmacology , Hypoglycemic Agents/pharmacology , Neuralgia/drug therapy , Amidohydrolases/metabolism , Animals , Antineoplastic Agents/adverse effects , Disease Models, Animal , Dose-Response Relationship, Drug , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Humans , Hypoglycemic Agents/chemical synthesis , Hypoglycemic Agents/chemistry , Molecular Structure , Neuralgia/metabolism , Rats , Structure-Activity RelationshipABSTRACT
This study describes successful method development and separation of two stereo isomers of 2-[4-(methylsulfonyl)phenyl]-3-(3(R)-oxocyclopentyl)propanoic acid by reverse phase high-performance liquid chromatography. Baseline resolution was achieved on a J'sphere-ODS-H80 (150 mm × 4.6 mm, 4 µm) column using mobile phase consisting of 0.05% triflouroacetic acid in water-acetonitrile (85:15, v/v) at a flow rate of 1.0 ml/min. The detection was carried out at 228 nm. The title compound, in turn, can be obtained by C-alkylation of methyl 2-[4-(methylthio)phenyl]acetate with 2(S)-iodomethyl-8,8-dimethyl-6,10-dioxaspiro[4.5]decane followed by consecutive hydrolysis and oxidation. The partially validated analytical method (system suitability, peak homogeneity, linearity, precision, robustness, and solution stability) has limit of detection and limit of quantification, 0.15 and 0.50 µg/ml respectively. Alternatively, the new method is being routinely utilized to monitor epimerization of α-carbon of the propanoic acid in the title compound by crystallization-induced dynamic resolution.
Subject(s)
Chromatography, High Pressure Liquid/methods , Chromatography, Reverse-Phase/methods , Organic Chemistry Phenomena , Propionates/chemistry , Sulfhydryl Compounds/chemistry , Acetonitriles/chemistry , Alkylation , Hydrolysis , Isomerism , Oxidation-Reduction , Solutions/chemistryABSTRACT
Stereoselective synthesis of the potentially biologically valuable 5beta-lanosteroidal-type backbone was achieved via anionic cycloaddition. Synthesis of the two new bicyclic Nazarov intermediates 14 and 40 and their cycloaddition with chiral cyclohexenone 25 and further functional group manipulations resulted in highly functionalized tetracyclic intermediates 28 and 44. These synthetic intermediates could lead to the total synthesis of new lanosterol-based inhibitors.
