ABSTRACT
NLRP3 is a molecular sensor recognizing a wide range of danger signals. Its activation leads to the assembly of an inflammasome that allows for activation of caspase-1 and subsequent maturation of IL-1ß and IL-18, as well as cleavage of Gasdermin-d and pyroptotic cell death. The NLRP3 inflammasome has been implicated in a plethora of diseases including gout, type 2 diabetes, atherosclerosis, Alzheimer's disease, and cancer. In this publication, we describe the discovery of a novel, tricyclic, NLRP3-binding scaffold by high-throughput screening. The hit (1) could be optimized into an advanced compound NP3-562 demonstrating excellent potency in human whole blood and full inhibition of IL-1ß release in a mouse acute peritonitis model at 30 mg/kg po dose. An X-ray structure of NP3-562 bound to the NLRP3 NACHT domain revealed a unique binding mode as compared to the known sulfonylurea-based inhibitors. In addition, NP3-562 shows also a good overall development profile.
Subject(s)
Diabetes Mellitus, Type 2 , Gout , Mice , Animals , Humans , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Inflammasomes/metabolism , Diabetes Mellitus, Type 2/metabolism , Macrophages/metabolism , Interleukin-1beta/metabolism , Caspase 1/metabolismABSTRACT
G-protein-coupled receptor SUCNR1 (succinate receptor 1 or GPR91) senses the citric cycle intermediate succinate and is implicated in various pathological conditions such as rheumatoid arthritis, liver fibrosis, or obesity. Here, we describe a novel SUCNR1 antagonist scaffold discovered by high-throughput screening. The poor permeation and absorption properties of the most potent compounds, which were zwitterionic in nature, could be improved by the formation of an internal salt bridge, which helped in shielding the two opposite charges and thus also the high polarity of zwitterions with separated charges. The designed compounds containing such a salt bridge reached high oral bioavailability and oral exposure. We believe that this principle could find a broad interest in the medicinal chemistry field as it can be useful not only for the modulation of properties in zwitterionic compounds but also in acidic or basic compounds with poor permeation.
Subject(s)
Benzamides/pharmacology , Phenylacetates/pharmacology , Receptors, G-Protein-Coupled/antagonists & inhibitors , Animals , Benzamides/chemical synthesis , Benzamides/metabolism , Benzamides/pharmacokinetics , Cell Line , Drug Discovery , Humans , Male , Mice, Inbred C57BL , Phenylacetates/chemical synthesis , Phenylacetates/metabolism , Phenylacetates/pharmacokinetics , Protein Binding , Rats , Receptors, G-Protein-Coupled/metabolism , Static ElectricityABSTRACT
The tricarboxylic acid cycle intermediate succinate is involved in metabolic processes and plays a crucial role in the homeostasis of mitochondrial reactive oxygen species1. The receptor responsible for succinate signalling, SUCNR1 (also known as GPR91), is a member of the G-protein-coupled-receptor family2 and links succinate signalling to renin-induced hypertension, retinal angiogenesis and inflammation3-5. Because SUCNR1 senses succinate as an immunological danger signal6-which has relevance for diseases including ulcerative colitis, liver fibrosis7, diabetes and rheumatoid arthritis3,8-it is of interest as a therapeutic target. Here we report the high-resolution crystal structure of rat SUCNR1 in complex with an intracellular binding nanobody in the inactive conformation. Structure-based mutagenesis and radioligand-binding studies, in conjunction with molecular modelling, identified key residues for species-selective antagonist binding and enabled the determination of the high-resolution crystal structure of a humanized rat SUCNR1 in complex with a high-affinity, human-selective antagonist denoted NF-56-EJ40. We anticipate that these structural insights into the architecture of the succinate receptor and its antagonist selectivity will enable structure-based drug discovery and will further help to elucidate the function of SUCNR1 in vitro and in vivo.
Subject(s)
Biphenyl Compounds/chemistry , Biphenyl Compounds/pharmacology , Piperazines/chemistry , Piperazines/pharmacology , Receptors, G-Protein-Coupled/antagonists & inhibitors , Receptors, G-Protein-Coupled/chemistry , Animals , Apoproteins/antagonists & inhibitors , Apoproteins/chemistry , Apoproteins/metabolism , Crystallography, X-Ray , Humans , Models, Molecular , Rats , Receptors, G-Protein-Coupled/metabolism , Receptors, Purinergic P2Y1/chemistry , Signal Transduction , Single-Domain Antibodies/chemistry , Species Specificity , Succinic Acid/metabolismABSTRACT
When SUCNR1/GPR91-expressing macrophages are activated by inflammatory signals, they change their metabolism and accumulate succinate. In this study, we show that during this activation, macrophages release succinate into the extracellular milieu. They simultaneously up-regulate GPR91, which functions as an autocrine and paracrine sensor for extracellular succinate to enhance IL-1ß production. GPR91-deficient mice lack this metabolic sensor and show reduced macrophage activation and production of IL-1ß during antigen-induced arthritis. Succinate is abundant in synovial fluids from rheumatoid arthritis (RA) patients, and these fluids elicit IL-1ß release from macrophages in a GPR91-dependent manner. Together, we reveal a GPR91/succinate-dependent feed-forward loop of macrophage activation and propose GPR91 antagonists as novel therapeutic principles to treat RA.
Subject(s)
Arthritis, Rheumatoid/etiology , Macrophages/metabolism , Receptors, G-Protein-Coupled/physiology , Succinic Acid/metabolism , Animals , Arthritis, Rheumatoid/metabolism , Female , Humans , Interleukin-1beta/metabolism , Lipopolysaccharides/pharmacology , Mice , Mice, Inbred C57BL , Receptors, G-Protein-Coupled/antagonists & inhibitors , U937 CellsABSTRACT
A novel series of pyrazolo[1,5a]pyrimidines was optimized to target lymphocyte-specific kinase (Lck). An efficient synthetic route was developed and SAR studies toward activity and selectivity are described, leading to Lck inhibitors with enzymatic, cellular and in vivo potency.
Subject(s)
Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/antagonists & inhibitors , Administration, Oral , Animals , Humans , Interleukin-2/metabolism , Lymphocyte Activation/drug effects , Mice , Microsomes, Liver/metabolism , Pyrimidines/pharmacology , Rats , Structure-Activity RelationshipABSTRACT
The one-pot three-component reaction of terminal alkynes, aldehydes and secondary amines in the presence of copper(I) bromide/quinap is reported. The reaction scope has been determined and a broad variety of all three components has been used, which afforded the corresponding propargylamines in good to excellent yields and moderate to very good enantioselectivities. The reaction showed a strong positive nonlinear effect. The transformation of a propargylamine intermediate into the alkaloid (S)-(+)-coniine has also been described.
Subject(s)
Bromides/chemistry , Copper/chemistry , Pargyline/analogs & derivatives , Propylamines/chemical synthesis , Aldehydes/chemistry , Alkynes/chemistry , Amines/chemistry , Catalysis , Pargyline/chemical synthesis , StereoisomerismABSTRACT
2-Phenallyl was found to be a versatile protecting group of primary amines for the asymmetric one-pot three-component synthesis of propargylamines which leads to enantiomeric excess of up to 96%; it can be easily removed with a palladium(0)-catalyzed allylic substitution using 1,3-dimethylbarbituric acid as a nucleophile.
ABSTRACT
[reaction: see text] Various nitro-substituted aryl and heteroaryl iodides undergo an iodine-magnesium exchange reaction when treated with PhMgCl leading to nitro-containing magnesium organometallics. These Grignard reagents display an excellent stability at temperatures below -40 degrees C and do not undergo electron-transfer reactions. They react as expected with various electrophiles.
ABSTRACT
The one-pot three-component addition reaction of trimethylsilylacetylene, aldehydes and dibenzylamine provides in the presence of CuBr/Quinap as catalyst, various enantiomerically enriched propargylamines in good yields (up to 99%) and excellent enantiomeric excess (up to 98%ee) which can be used as a key intermediate in the synthesis of the alkaloid (S)-(+)-coniine.
ABSTRACT
Organomagnesium reagents occupy a central position in synthetic organic and organometallic chemistry. Recently, the halogen-magnesium exchange has considerably extended the range of functionalized Grignard reagents available for synthetic purposes. Functional groups such as esters, nitriles, iodides, imines, or even nitro groups can be present in a wide range of aromatic and heterocyclic organomagnesium reagents. Also various highly functionalized alkenyl magnesium species can be prepared. These recent developments as well as new applications of organomagnesium reagents in cross-coupling reactions and amination reactions will be covered in this Review.
ABSTRACT
The first copper(I) bromide/Quinap-catalyzed synthesis of enantiomerically enriched propargylamines by addition of alkynes to enamines is reported. Various functionalized terminal alkynes add smoothly to Nprotected enamines to afford the corresponding amines in good to high yields and moderate to good enantiomeric excesses. The influence of the metal salt, the ligand, and the protecting group on the conversion, the reaction rate, and the stereoselectivity of the reaction are investigated. The scope of the reaction and further transformations of the resulting propargylamines (deprotection, Pauson-Khand reaction) are also described.