RESUMO
Decreased activity and expression of the G-protein coupled receptor GPR88 is linked to many behavior-linked neurological disorders. Published preclinical GPR88 allosteric agonists all have in vivo pharmacokinetic properties that preclude their progression to the clinic, including high lipophilicity and poor brain penetration. Here, we describe our attempts to improve GPR88 agonists' drug-like properties and our analysis of the trade-offs required to successfully target GPR88's allosteric pocket. We discovered two new GPR88 agonists: One that reduced morphine-induced locomotor activity in a murine proof-of-concept study, and the atropoisomeric BI-9508, which is a brain penetrant and has improved pharmacokinetic properties and dosing that recommend it for future in vivo studies in rodents. BI-9508 still suffers from high lipophilicity, and research on this series was halted. Because of its utility as a tool compound, we now offer researchers access to BI-9508 and a negative control free of charge via Boehringer Ingelheim's open innovation portal opnMe.com.
Assuntos
Encéfalo , Receptores Acoplados a Proteínas G , Animais , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/metabolismo , Camundongos , Encéfalo/metabolismo , Encéfalo/efeitos dos fármacos , Humanos , Descoberta de Drogas , Masculino , Relação Estrutura-Atividade , Camundongos Endogâmicos C57BL , Morfina/farmacologia , Morfina/farmacocinéticaRESUMO
Ion channels are attractive drug targets for many therapeutic applications. However, high-throughput screening (HTS) of drug candidates is difficult and remains very expensive. We thus assessed the suitability of the bioluminescence resonance energy transfer (BRET) technique as a new HTS method for ion-channel studies by taking advantage of our recently characterized intra- and intermolecular BRET probes targeting the transient receptor potential vanilloid type 1 (TRPV1) ion channel. These BRET probes monitor conformational changes during TRPV1 gating and subsequent coupling with calmodulin, two molecular events that are intractable using reference techniques such as automated calcium assay (ACA) and automated patch-clamp (APC). We screened the small-sized Prestwick chemical library, encompassing 1200 compounds with high structural diversity, using either intra- and intermolecular BRET probes or ACA. Secondary screening of the detected hits was done using APC. Multiparametric analysis of our results shed light on the capability of calmodulin inhibitors included in the Prestwick library to inhibit TRPV1 activation by capsaicin. BRET was the lead technique for this identification process. Finally, we present data exemplifying the use of intramolecular BRET probes to study other transient receptor potential (TRP) channels and non-TRPs ion channels. Knowing the ease of use of BRET biosensors and the low cost of the BRET technique, these assays may advantageously be included for extending ion-channel drug screening. SIGNIFICANCE STATEMENT: This study screened a chemical library against TRPV1 ion channel using bioluminescence resonance energy transfer (BRET) molecular probes and compared the results with the ones obtained using reference techniques such as automated calcium assay and automated patch-clamp. Multiparametric analysis of our results shed light on the capability of calmodulin antagonists to inhibit chemical activation of TRPV1 and indicates that BRET probes may advantageously be included in ion channel drug screening campaigns.
Assuntos
Técnicas de Transferência de Energia por Ressonância de Bioluminescência/métodos , Descoberta de Drogas/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Ensaios de Triagem em Larga Escala/métodos , Canais de Cátion TRPV/metabolismo , Bioensaio/métodos , Cálcio/química , Calmodulina/antagonistas & inibidores , Células HEK293 , Humanos , Ligantes , Potenciais da Membrana/efeitos dos fármacos , Técnicas de Patch-Clamp , Bibliotecas de Moléculas Pequenas , Canais de Cátion TRPV/agonistas , Canais de Cátion TRPV/antagonistas & inibidoresRESUMO
The metabotropic glutamate receptor 4 (mGluR4) is an emerging target for the treatment of Parkinson's disease (PD). However, since the discovery of its therapeutic potential, no ligand has been successfully developed enough to be tested in the clinic. In the present paper, we report for the first time the medicinal chemistry efforts conducted around the pharmacological tool (-)-PHCCC. This work led to the identification of compound 40, a potent and selective mGluR4 positive allosteric modulator (PAM) with good water solubility and demonstrating consistent activity across validated preclinical rodent models of PD motor symptoms after intraperitoneal administration: haloperidol-induced catalepsy in mouse and the rat 6-hydroxydopamine (6-OHDA) lesion model. Moreover, we also describe the identification of compound 60 a close analogue of compound 40 with improved pharmacokinetic profile after oral administration. On the basis of its favorable and unique preclinical profile, compound 60 (PXT002331, now foliglurax) was nominated as a candidate for clinical development.
Assuntos
Antiparkinsonianos/farmacologia , Encéfalo/efeitos dos fármacos , Descoberta de Drogas , Receptores de Glutamato Metabotrópico/efeitos dos fármacos , Regulação Alostérica , Animais , Antiparkinsonianos/farmacocinética , Cromatografia Líquida , Células HEK293 , Humanos , Espectrometria de Massas , Camundongos , Espectroscopia de Prótons por Ressonância Magnética , Ratos , Relação Estrutura-AtividadeRESUMO
The Pd-PEPPSI-IPentCl precatalyst (PEPPSI=pyridine-enhanced precatalyst preparation stabilisation initiation) has been demonstrated to be highly effective in the coupling of hetero(aryl)chlorides to free 2-aminopyridine substrates to produce N-(hetero)aryl-2-aminopyridine derivatives. The catalyst has proven to be competent in a number of other difficult cross-coupling reactions owing to the combination of the 3-pentyl-substituted N-aryl groups and the chlorines on the backbone of the N-heterocyclic carbene (NHC) core. This same reactivity here allows couplings to take place under very mild conditions (e.g., NaBHT (BHT=2,6-di-tert-butyl-4-methylphenol) or carbonate base) such that sensitive functional groups including esters, ketones and nitriles are tolerated. Key is that the same bulk that drives the cross-coupling also mitigates poisoning of the Pd centre with the 2-aminopyridine functionality in the starting materials and/or products, which forces the catalyst into inactive, stable resting states.
RESUMO
INTRODUCTION: This review focuses on the medicinal chemistry efforts directed toward the identification of competitive and noncompetitive antagonists of glutamate at group II metabotropic glutamate receptors (mGluRII: mGlu2/3 and mGlu2). This class of compounds holds promise for the treatment of CNS disorders such as major depression, cognitive deficits and sleep-wake disorders, and several pharmaceutical companies are advancing mGluRII antagonists from discovery research into clinical development. AREA COVERED: This review article covers for the first time the patent applications that were published on mGlu2/3 orthosteric and allosteric antagonists between January 2005 and September 2014, with support from the primary literature, posters and oral communications from international congresses. Patent applications published prior to 2005 for which compositions of matter were largely described in peer review articles are briefly discussed with main findings. EXPERT OPINION: Recent advances in the prodrug approach of novel mGlu2/3 orthosteric antagonists combined with the design of novel mGlu2/3 and mGlu2 negative allosteric modulators provide new therapeutic opportunities for neurologic and psychiatric disorders.
Assuntos
Doenças do Sistema Nervoso Central/tratamento farmacológico , Indústria Farmacêutica/legislação & jurisprudência , Antagonistas de Aminoácidos Excitatórios/uso terapêutico , Patentes como Assunto , Receptores de Glutamato Metabotrópico/antagonistas & inibidores , Animais , Doenças do Sistema Nervoso Central/metabolismo , Desenho de Fármacos , Antagonistas de Aminoácidos Excitatórios/química , Antagonistas de Aminoácidos Excitatórios/farmacologia , Humanos , Estrutura Molecular , Receptores de Glutamato Metabotrópico/química , Receptores de Glutamato Metabotrópico/metabolismo , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-AtividadeRESUMO
Using an mGluR2 FRET-based binding assay, binders of the transmembrane region devoid of functional activity were identified. It is reported that slight chemical modifications of these SAMs can dramatically change activity of the resulting analogues without altering their affinities. Starting from compound 1, three mGluR2 NAMs showing also mGluR3 PAM activities were obtained. SAMs therefore represent a useful approach to explore the chemical space for GPCR allosteric modulator identification.
Assuntos
Benzopiranos/síntese química , Fármacos Atuantes sobre Aminoácidos Excitatórios/síntese química , Receptores de Glutamato Metabotrópico/fisiologia , Regulação Alostérica , Benzopiranos/química , Benzopiranos/farmacologia , Cálcio/metabolismo , Linhagem Celular , Fármacos Atuantes sobre Aminoácidos Excitatórios/química , Fármacos Atuantes sobre Aminoácidos Excitatórios/farmacologia , Transferência Ressonante de Energia de Fluorescência , Ensaios de Triagem em Larga Escala , Humanos , Bibliotecas de Moléculas Pequenas , Relação Estrutura-AtividadeRESUMO
Dihydrofolate reductase (DHFR) is a vital metabolic enzyme and thus a clinically prominent target in the design of antimetabolites. In this work, we identify 1,4-bis-{[N-(1-imino-1-guanidino-methyl)]sulfanylmethyl}-3,6-dimethyl-benzene (compound 1) as the correct structure of the previously reported DHFR inhibitor 1,4-bis-{(iminothioureidomethyl)aminomethyl}-3,6-dimethyl-benzene (compound 2). The fact that compound 1 has an uncharacteristic structure for DHFR inhibitors, and an affinity (KI of 11.5 nM) comparable to potent inhibitors such as methotrexate and trimethoprim, made this inhibitor of interest for further analysis. We have conducted a characterization of the primary interactions of compound 1 and DHFR using a combination of X-ray structure and SAR analysis. The crystal structure of E. coli DHFR in complex with compound 1 and NADPH reveals that one portion of this inhibitor exploits a unique binding surface, the M20 loop. The importance of this interface was further confirmed by SAR analysis and additional structural characterization.
Assuntos
Antagonistas do Ácido Fólico/química , Guanidinas/química , Tetra-Hidrofolato Desidrogenase/química , Sítios de Ligação , Técnicas de Química Combinatória , Cristalografia por Raios X , Escherichia coli/enzimologia , Antagonistas do Ácido Fólico/síntese química , Metotrexato/química , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-Atividade , Trimetoprima/químicaRESUMO
A new family of mGlu receptor orthosteric ligands called APTCs was designed and synthesized using a parallel chemistry approach. Amongst 65 molecules tested on mGlu4, mGlu6 and mGlu8 subtypes, (2S,4S)-4-amino-1-[(E)-3-carboxyacryloyl]pyrrolidine-2,4-dicarboxylic acid (8a06-FP0429) has been shown to be a full mGlu4 agonist and a partial mGlu8 agonist. In addition, 8a06 was shown to be selective versus group I and II mGlu subtypes. A possible explanation for this efficacy difference is proposed by docking experiment performed with molecular model of the receptor.
Assuntos
Ácidos Carboxílicos/química , Ácidos Carboxílicos/farmacologia , Desenho de Fármacos , Pirrolidinas/química , Receptores de Glutamato Metabotrópico/agonistas , Receptores de Glutamato Metabotrópico/metabolismo , Aminação , Sítios de Ligação , Cálcio/metabolismo , Ácidos Carboxílicos/síntese química , Linhagem Celular , Humanos , Modelos Moleculares , Estrutura Molecular , Receptores de Glutamato Metabotrópico/química , Receptores de Glutamato Metabotrópico/classificação , Relação Estrutura-AtividadeRESUMO
It has been demonstrated previously by us that guanide-containing compounds (1 and 2) can inhibit significantly dihydrofolate reductase (DHFR). In this report, we have produced an array of alkyl- and aryl-based biguanide compounds using microwave irradiation. Further, we have demonstrated the use of TMSCl for the first time as an excellent and practical catalyst for the formation of alkyl and aryl biguanides. Using these methods, we prepared a 60-compound collection, of which one compound (21g) showed approximately one-half of the inhibitory activity of the parent compound 2.
Assuntos
Biguanidas/síntese química , Antagonistas do Ácido Fólico/síntese química , Tetra-Hidrofolato Desidrogenase/efeitos dos fármacos , Técnicas de Química Combinatória , Inibidores Enzimáticos/síntese química , Escherichia coli/enzimologia , Filtração , Micro-OndasRESUMO
In recent years, a number of new methods have been reported that make use of immobilized enzymes either on microarrays or in bioaffinity columns for high-throughput screening of compound libraries. A key question that arises in such methods is whether immobilization may alter the intrinsic catalytic and inhibition constants of the enzyme. Herein, we examine how immobilization within sol-gel-derived materials affects the catalytic constant (kcat), Michaelis constant (KM), and inhibition constant (KI) of the clinically relevant enzymes Factor Xa, dihydrofolate reductase, cyclooxygenase-2, and gamma-glutamyl transpeptidase. These enzymes were encapsulated into sol-gel-derived glasses produced from either tetraethyl orthosilicate (TEOS) or the newly developed silica precursor diglyceryl silane (DGS). It was found that the catalytic efficiency and long-term stability of all enzymes were improved upon entrapment into DGS-derived materials relative to entrapment in TEOS-based glasses, likely owing to the liberation of the biocompatible reagent glycerol from DGS. The KM values of enzymes entrapped in DGS-derived materials were typically higher than those in solution, whereas upon entrapment, kcat values were generally lowered by a factor of 1.5-7 relative to the value in solution, indicating that substrate turnover was limited by partitioning effects or diffusion through the silica matrix. Nonetheless, the apparent KI value for the entrapped enzyme was in most cases within error of the value in solution, and even in the worst case, the values differed by no more than a factor of 3. The implications of these findings for high-throughput screening are discussed.
Assuntos
Avaliação Pré-Clínica de Medicamentos/métodos , Inibidores Enzimáticos/farmacologia , Enzimas Imobilizadas/química , Géis/química , Animais , Catálise , Estabilidade Enzimática , CinéticaRESUMO
An effective synthesis of 4-(5-iodo-3-methylpyrazolyl) phenylsulfonamide has been developed. This aromatic iodide template served as an efficient oxidative addition partner for the preparation of a solution-phase library of Celecoxib analogues via Suzuki coupling using Pd/C, a readily filterable catalyst.
Assuntos
Inibidores de Ciclo-Oxigenase/síntese química , Isoenzimas/efeitos dos fármacos , Paládio/química , Prostaglandina-Endoperóxido Sintases/efeitos dos fármacos , Pirazóis/síntese química , Sulfonamidas/síntese química , Catálise , Celecoxib , Ciclo-Oxigenase 2 , Inibidores de Ciclo-Oxigenase 2 , Indicadores e Reagentes , Iodetos , Oxirredução , Pirazóis/química , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
Microwave heating methods have been combined with the use of solid-supported catalysts to produce small solution-phase libraries of medicinally-relevant compounds. Palladium supported on charcoal (Pd/C) has been used to produce libraries of pyrazole compounds for screening in COX II studies via Suzuki cross coupling reactions, while the same catalyst has been used also to produce styryl-based nAChR compounds using analogous chemistry. Although the reaction substrates are very different (aryl vs. vinyl), this catalyst system provided consistently good and reliable results. The use of a polystyrene-supported Ru catalyst for ring-closing metathesis (RCM) reactions was also evaluated to prepare benzolactam structures for evaluation as factor Xa inhibitors.