ABSTRACT
Inhibitors of leucine-rich repeat kinase 2 (LRRK2) and mutants, such as G2019S, have potential utility in Parkinson's disease treatment. Fragment hit-derived pyrrolo[2,3-d]pyrimidines underwent optimization using X-ray structures of LRRK2 kinase domain surrogates, based on checkpoint kinase 1 (CHK1) and a CHK1 10-point mutant. (2R)-2-Methylpyrrolidin-1-yl derivative 18 (LRRK2 G2019S cKi 0.7 nM, LE 0.66) was identified, with increased potency consistent with an X-ray structure of 18/CHK1 10-pt. mutant showing the 2-methyl substituent proximal to Ala147 (Ala2016 in LRRK2). Further structure-guided elaboration of 18 gave the 2-[(1,3-dimethyl-1H-pyrazol-4-yl)amino] derivative 32. Optimization of 32 afforded diastereomeric oxolan-3-yl derivatives 44 and 45, which demonstrated a favorable in vitro PK profile, although they displayed species disconnects in the in vivo PK profile, and a propensity for P-gp- and/or BCRP-mediated efflux in a mouse model. Compounds 44 and 45 demonstrated high potency and exquisite selectivity for LRRK2 and utility as chemical probes for the study of LRRK2 inhibition.
Subject(s)
Checkpoint Kinase 1/chemistry , Drug Design , Leucine-Rich Repeat Serine-Threonine Protein Kinase-2/antagonists & inhibitors , Protein Kinase Inhibitors/pharmacology , Pyrimidines/pharmacology , Pyrroles/pharmacology , Checkpoint Kinase 1/metabolism , Crystallography, X-Ray , Dose-Response Relationship, Drug , HEK293 Cells , Humans , Leucine-Rich Repeat Serine-Threonine Protein Kinase-2/metabolism , Models, Molecular , Molecular Structure , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/chemistry , Pyrimidines/chemical synthesis , Pyrimidines/chemistry , Pyrroles/chemical synthesis , Pyrroles/chemistry , Structure-Activity RelationshipABSTRACT
Mutations in leucine-rich repeat kinase 2 (LRRK2), such as G2019S, are associated with an increased risk of developing Parkinson's disease. Surrogates for the LRRK2 kinase domain based on checkpoint kinase 1 (CHK1) mutants were designed, expressed in insect cells infected with baculovirus, purified, and crystallized. X-ray structures of the surrogates complexed with known LRRK2 inhibitors rationalized compound potency and selectivity. The CHK1 10-point mutant was preferred, following assessment of surrogate binding affinity with LRRK2 inhibitors. Fragment hit-derived arylpyrrolo[2,3-b]pyridine LRRK2 inhibitors underwent structure-guided optimization using this crystallographic surrogate. LRRK2-pSer935 HEK293 IC50 data for 22 were consistent with binding to Ala2016 in LRRK2 (equivalent to Ala147 in CHK1 10-point mutant structure). Compound 22 was shown to be potent, moderately selective, orally available, and brain-penetrant in wild-type mice, and confirmation of target engagement was demonstrated, with LRRK2-pSer935 IC50 values for 22 in mouse brain and kidney being 1.3 and 5 nM, respectively.
Subject(s)
Leucine-Rich Repeat Serine-Threonine Protein Kinase-2/antagonists & inhibitors , Protein Kinase Inhibitors/therapeutic use , Animals , Brain/metabolism , Checkpoint Kinase 1 , Crystallography/methods , HEK293 Cells , Humans , Kidney/metabolism , Leucine-Rich Repeat Serine-Threonine Protein Kinase-2/genetics , Mice , Mutation , Parkinson Disease/genetics , Protein Binding , Protein Domains , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacokineticsABSTRACT
We herein report the discovery of a novel class of antagonists of the human adenosine A2B receptor. This low molecular weight scaffold has been optimized to offer derivatives with potential utility for the alleviation of conditions associated with this receptor subtype, such as nociception, diabetes, asthma and COPD. Furthermore, preliminary pharmacokinetic analysis has revealed compounds with profiles suitable for either inhaled or systemic routes of administration.
Subject(s)
Adenosine A2 Receptor Antagonists , Pyrimidines/chemistry , Administration, Inhalation , Animals , Asthma/drug therapy , Drug Design , Humans , Pulmonary Disease, Chronic Obstructive/drug therapy , Pyrimidines/chemical synthesis , Pyrimidines/pharmacokinetics , Rats , Receptor, Adenosine A2A/metabolism , Receptor, Adenosine A2B/metabolismABSTRACT
Beta-allyloxy and beta-propargyloxy tert-butyl sulfoxides undergo tandem sulfoxide eliminination-intramolecular sulfenic acid addition reactions to produce 1,4-oxathiane S-oxides.
