Discovery of Novel PI3Kδ Inhibitors Based on the p110δ Crystal Structure.

PI3Kδ is a key mediator of B-cell receptor signaling and plays an important role in the pathogenesis of certain hematological malignancies, such as chronic lymphocytic leukemia. Idelalisib, which targets PI3Kδ specifically, is the first approved PI3K inhibitor for cancer therapy. Recently, we carried out virtual screening, cell-based assays, adapta kinase assays, and molecular dynamic analysis to discover novel PI3Kδ inhibitors and identified NSC348884 as a lead PI3Kδ inhibitor. NSC348884 had an excellent docking score, potent PI3Kδ-inhibitory activity, antitumor effects on various cancer cell lines, and a favorable binding mode with the active site of PI3Kδ. Moreover, through the structural modification of NSC348884, we further discovered comp#1, which forms H-bonds with both Val828 and Lys779 in the ATP binding pocket of PI3Kδ, with a more favorable conformation binding to PI3Kδ. In addition, we found that N1, N1, N2-trimethyl-N2-((6-methyl-1H-benzo[d]imidazol-2-yl) methyl) ethane-1,2-diamine might be a potential scaffold structure. Thus, the result of this study provides a far more efficient approach for discovering novel inhibitors targeting PI3Kδ.

Exploring Dual Agonists for PPARα/γ Receptors using Pharmacophore Modeling, Docking Analysis and Molecule Dynamics Simulation.

BACKGROUND: The Peroxisome Proliferator-Activated Receptors (PPARs) are ligandactivated transcription factors belonging to the nuclear receptor family. The roles of PPARα in fatty acid oxidation and PPARγ in adipocyte differentiation and lipid storage have been widely characterized. Compounds with dual PPARα/γ activity have been proposed, combining the benefits of insulin sensitization and lipid lowering into one drug, allowing a single drug to reduce hyperglycemia and hyperlipidemia while preventing the development of cardiovascular complications. METHODS: The new PPARα/γ agonists were screened through virtual screening of pharmacophores and molecular dynamics simulations. First, in the article, the constructed pharmacophore was used to screen the Ligand Expo Components-pub database to obtain the common structural characteristics of representative PPARα/γ agonist ligands. Then, the accepted ligand structure was modified and replaced to obtain 12 new compounds. Using molecular docking, ADMET and molecular dynamics simulation methods to screen the designed 12 ligands, analyze their docking scores when they bind to the PPARα/γ dual targets, their stability and pharmacological properties when they bind to the PPARα/γ dual targets. RESULTS: We performed pharmacophore-based virtual screening for 22949 molecules in Ligand Expo Components-pub database. The compounds that were superior to the original ligand were performed structural analysis and modification, and a series of compounds with novel structures were designed. Using precise docking, ADMET prediction and molecular dynamics methods to screen and verify newly designed compounds, and the above compounds show higher docking scores and lower side effects. CONCLUSION: 9 new PPARα/γ agonists were obtained by pharmacophore modeling, docking analysis and molecular dynamics simulation.

In-silico identification of peroxisome proliferator-activated receptor (PPAR)α/γ agonists from Ligand Expo Components database.

PPARα and PPARγ play important roles in regulating glucose and lipid metabolism. In recent years, the development of dual PPAR agonists has become a hot topic in the field of anti-diabetic medicinal chemistry. The dual PPARα/γ agonists can both improve metabolism and reduce side effects caused by single drugs, and has become a promising strategy for designing effective drugs for the treatment of type 2 diabetes. In this study, by means of virtual screening, molecular docking and ADMET prediction technology, a representative compound with higher docking score, lower toxicity than original ligands was gained from the Ligand Expo Components database. It was observed through MD simulation that the representative compound not only has the function of activating the PPARα target and the PPARγ target, but also show a more favorable binding mode when the representative compound binds to the two receptors compared to the original ligands. Our results provided an approach to rapidly find novel PPARα/γ dual agonists for the treatment of type 2 diabetes mellitus (T2DM).This paper explores novel compounds targeting PPARα/γ dual agonists by using molecular docking, ADMET prediction, and molecular dynamics simulation methods. The specific flowchart is as follows: HighlightsThe results show that the skeleton of compound M80 is not only similar to Saroglitazar but also higher than that of Saroglitazar in activity.This study explained the binding modes of saroglitazar-PPARα/γ complexes and provided structure reference for the research and development of novel PPARα/γ dual agonists.

The influence of genetic polymorphisms in drug metabolism enzymes and transporters on the pharmacokinetics of different fluvastatin formulations.

The purpose of the present study was to investigate the impact of genetic polymorphism on fluvastatin pharmacokinetics. In addition, we compared the fluvastatin pharmacokinetics differences between extended-release (ER) 80 mg tablet and immediate-release (IR) 40 mg capsule in terms of drug metabolism enzyme and transporter genetic polymorphisms. In this open-label, randomized, two-period, two-treatment, crossover study (n = 24), effects of ABCG2, SLCO1B1, ABCB1, CYP2C9 and CYP3A5 polymorphisms on the pharmacokinetics of fluvastatin were analyzed. The administration dosage for IR 40 mg and ER 80 mg were twice and once daily, respectively, for total 7 d. Blood samples for pharmacokinetic evaluation were taken on the 1st and 7th d. The lower exposure following ER was observed. For ER tablets, SLCO1B1 T521C genotype correlated with AUC0-24 of repeat doses (P = 0.010). SLCO1B1 T521C genotype had no statistically significant effect on AUC0-24 of IR capsule of fluvastatin after single or repeated doses. In vitro study demonstrated that when the concentration of fluvastatin was low (< 1 µmol/l), the uptake of fluvastatin in the HEK293-OATP1B1 with SLCO1B1 521TT (Km =0.18 µmol/l) was faster than that with SLCO1B1 521CC (Km =0.49 µmol/l), On the other hand, when concentration reached to higher level (> 1 µmol/l), transport velocity of fluvastatin by HEK293-OATP1B1 with SLCO1B1 521TT (Km  = 11.4 µmol/l) and with SLCO1B1 521TCC (Km =15.1 µmol/l) tend to be the same. It suggests that the increased effect of SLCO1B1 T521C genotype on ER formulation of fluvastatin was mainly caused by lower blood concentrations. We recommend that formulation should be incorporated into future pharmacogenomics studies.

Discovery of novel and highly selective PI3Kδ inhibitors based on the p110δ crystal structure.

Communicated by Ramaswamy H. Sarma.

Virtual identification of novel PPARα/γ dual agonists by 3D-QSAR, molecule docking and molecular dynamics studies.

Peroxisome proliferator-activated receptors (PPARs) are considered important targets for the treatment of Type 2 diabetes (T2DM). To accelerate the discovery of PPAR α/γ dual agonists, the comparative molecular field analysis (CoMFA) were performed for PPARα and PPARγ, respectively. Based on the molecular alignment, highly predictive CoMFA model for PPARα was obtained with a cross-validated q2 value of 0.741 and a conventional r2 of 0.975 in the non-cross-validated partial least-squares (PLS) analysis, while the CoMFA model for PPARγ with a better predictive ability was shown with q2 and r2 values of 0.557 and 0.996, respectively. Contour maps derived from the 3D-QSAR models provided information on main factors towards the activity. Then, we carried out structural optimization and designed several new compounds to improve the predicted biological activity. To investigate the binding modes of the predicted compounds in the active site of PPARα/γ, a molecular docking simulation was carried out. Molecular dynamic (MD) simulations indicated that the predicted ligands were stable in the active site of PPARα/γ. Therefore, combination of the CoMFA and structure-based drug design results could be used for further structural alteration and synthesis and development of novel and potent dual agonists. AbbreviationsDMdiabetes mellitusT2DMtype 2 diabetesPPARsperoxisome proliferator-activated receptorsLBDDligand based drug design3D-QSARthree-dimensional quantitative structure activity relationshipCoMFAcomparative molecular field analysisPLSpartial least squareLOOleave-one-outq2cross-validated correlation coefficientONCoptimal number of principal componentsr2non-cross-validated correlation coefficientSEEstandard error of estimateFthe Fischer ratior2predpredictive correlation coefficientDBDDNA binding domainMDmolecular dynamicsRMSDroot-mean-square deviationRMSFroot mean square fluctuationsCommunicated by Ramaswamy H. Sarma.

Virtual identification of novel peroxisome proliferator-activated receptor (PPAR) α/δ dual antagonist by 3D-QSAR, molecule docking, and molecule dynamics simulation.

The therapeutic potential of PPARs antagonists extends beyond diabetes. PPARs antagonists represent a new drug class that holds promise as a broadly applicable therapeutic approach for cancer treatment. Thus, there is a strong need to develop a rational design strategy for creating PPARs antagonists. In this study, three-dimensional quantitative structure-activity relationship (3D-QSAR) models of PPARα receptor (CoMFA-1, q 2 = 0.636, r 2 = 0.953; CoMSIA-1, q 2 = 0.779, r 2 = 0.999) and PPARδ receptor (CoMFA-2, q 2 = 0.624, r 2 = 0.906; CoMSIA-2, q 2 = 0.627, r 2 = 0.959) were successfully constructed using 35 triazolone ring derivatives. Contour map analysis revealed that the electrostatic and hydrophobic fields played vital roles in the bioactivity of dual antagonists. Molecular docking studies suggested that the hydrogen bonding, electrostatic and hydrophobic interactions all influenced the binding of receptor-ligand complex. Based on the information obtained above, we designed a series of compounds. The docking results were mutually validated with 3D-QSAR results. Three-dimensional-QSAR and absorption, distribution, metabolism, excretion and toxicity (ADMET) predictions indicated that 19 newly designed compounds possessed excellent biological activity and physicochemical properties. In summary, this research could provide theoretical guidance for the structural optimization of novel PPARα and δ dual antagonists. Communicated by Ramaswamy H. Sarma.

Comparative research on the metabolism of metoprolol by four CYP2D6 allelic variants in vitro with LC-MS/MS.

Specific study about the effect of cytochrome P450 2D6 (CYP2D6) polymorphisms on the metabolism of clinic drugs is of great significance for drug safety investigation. Here, the interaction between CYP2D6 variants (*1, *2, *10, *39) and metoprolol (MET) was intensively researched in vitro from the aspect of drug-enzyme kinetic study. To obtain quantitative data, α-hydroxymetoprolol (main metabolite of MET) was selected as an ideal analyte and an LC-MS/MS method was adopted for sample determination. Firstly, by selecting suitable internal standard and optimizing separation condition, the LC-MS/MS method was established and validated. Then, the drug-enzyme incubation system was optimized by two parameters: incubation time and amount of enzyme. Lastly, the interaction between CYP2D6 allelic variants and MET was characterized by Km, Vmax and CLint. As a result, four CYP2D6 enzymes displayed diverse Km or Vmax towards MET and the values of CLint showed a wide range from 8.91 to 100%. Relative to CYP2D6*1 (CLint*1 = 100%), CYP2D6*2 demonstrated the second high catalytic activity (CLint*2/*1 = 74.87%) while CYP2D6*39 (CLint*39/*1 = 29.65%) and CYP2D6*10 (CLint*10/*1 = 8.91%) showed minimal catalytic activity. This comprehensive in vitro data suggested the prominent influence of CYP2D6 polymorphisms on the metabolism of MET, which could offer valuable information for personalized administration of MET in clinic.

Small Molecule Inhibitor that Stabilizes the Autoinhibited Conformation of the Oncogenic Tyrosine Phosphatase SHP2.

Genetic mutations in the phosphatase PTPN11 (SHP2) are associated with childhood leukemias. These mutations cause hyperactivation of SHP2 due to the disruption of the autoinhibitory conformation. By targeting the activation-associated protein conformational change, we have identified an SHP2 inhibitor ( E)-1-(1-(5-(3-(2,4-dichlorophenyl)acryloyl)-2-ethoxy-4-hydroxybenzyl)-1,2,5,6-tetrahydropyridin-3-yl)-1 H-benzo[ d]imidazol-2(3 H)-one (LY6, 1) using computer-aided drug design database screening combined with cell-based assays. This compound inhibited SHP2 with an IC50 value of 9.8 µM, 7-fold more selective for SHP2 than the highly related SHP1. Fluorescence titration, thermal shift, and microscale thermophoresis quantitative binding assays confirmed its direct binding to SHP2. This compound was further verified to effectively inhibit SHP2-mediated cell signaling and proliferation. Furthermore, mouse and patient leukemia cells with PTPN11 activating mutations were more sensitive to this inhibitor than wild-type cells. This small molecule SHP2 inhibitor has a potential to serve as a lead compound for further optimization studies to develop novel anti-SHP2 therapeutic agents.

Identification of novel PPARα/γ dual agonists by pharmacophore screening, docking analysis, ADMET prediction and molecular dynamics simulations.

PPARα and PPARγ play an important role in regulating glucose and lipid metabolism. The single and selective PPARα or PPARγ agonists have caused several side effects such as edema, weight gain and cardiac failure. In the recent years, the dual PPARs agonist development has become a hot topic in the antidiabetic medicinal chemistry field. In this paper, the compound CHEMBL230490 were gained from CHEMBL database, by means of complex-based pharmacophore (CBP) virtual screening, molecular docking, ADMET prediction and molecular dynamics (MD) simulations. The compound CHEMBL230490 not only displayed higher binding scores and better binding modes with the active site of PPARα a/γ, but also had more favorable the pharmacokinetic properties and toxicity evaluated by ADMET prediction. The representative compound CHEMBL230490 was performed to MDs for studying a stable binding conformation. The results indicated that the CHEMBL230490 might be a potential antidiabetic lead compound. The research provided a valuable approach in developing novel PPARα/γ dual agonists for the treatment of type 2 diabetes mellitus (T2DM).

Identification of novel PI3Kδ inhibitors by docking, ADMET prediction and molecular dynamics simulations.

BACKGROUND: Phosphoinositide-3-kinase Delta (PI3Kδ) plays a key role in B-cell signal transduction and inhibition of PI3Kδ is confirmed to have clinical benefit in certain types of activation of B-cell malignancies. Virtual screening techniques have been used to discover new molecules for developing novel PI3Kδ inhibitors with little side effects. METHOD: Computer aided drug design method were used to rapidly screen optimal PI3Kδ inhibitors from the Asinex database. Virtual screening based molecular docking was performed to find novel and potential lead compound targeting PI3Kδ, at first. Subsequently, drug likeness studies were carried out on the retrieved hits to evaluate and analyze their drug like properties such as absorption, distribution, metabolism, excretion, and toxicity (ADMET) for toxicity prediction. Three least toxic compounds were selected for the molecular dynamics (MD) simulations for 30 ns in order to validate its stability inside the active site of PI3Kδ receptor. RESULTS: Based on the present in silico analysis, two molecules have been identified which occupied the same binding pocket confirming the selection of active site. ASN 16296138 (Glide score: -12.175 kcal/mol, cdocker binding energy: -42.975 kcal/mol and ΔGbind value: -90.457 kcal/mol) and BAS 00227397 (Glide score: -10.988 kcal/mol, cdocker binding energy: -39.3376 kcal/mol and ΔGbind value: -81.953 kcal/mol) showed docking affinities comparatively much stronger than those of already reported known inhibitors against PI3Kδ. These two ligand's behaviors also showed consistency during the simulation of protein-ligand complexes for 30000 ps respectively, which is indicative of its stability in the receptor pocket. CONCLUSION: Compound ASN 16296138 and BAS 00227397 are potential candidates for experimental validation of biological activity against PI3Kδ in future drug discovery studies. This study smoothes the path for the development of novel leads with improved binding properties, high drug likeness, and low toxicity to humans for the treatment of cancer.

Systematic Structure-Activity Relationship (SAR) Exploration of Diarylmethane Backbone and Discovery of A Highly Potent Novel Uric Acid Transporter 1 (URAT1) Inhibitor.

In order to systematically explore and better understand the structure-activity relationship (SAR) of a diarylmethane backbone in the design of potent uric acid transporter 1 (URAT1) inhibitors, 33 compounds (1a-1x and 1ha-1hi) were designed and synthesized, and their in vitro URAT1 inhibitory activities (IC50) were determined. The three-round systematic SAR exploration led to the discovery of a highly potent novel URAT1 inhibitor, 1h, which was 200- and 8-fold more potent than parent lesinurad and benzbromarone, respectively (IC50 = 0.035 µM against human URAT1 for 1h vs. 7.18 µM and 0.28 µM for lesinurad and benzbromarone, respectively). Compound 1h is the most potent URAT1 inhibitor discovered in our laboratories so far and also comparable to the most potent ones currently under development in clinical trials. The present study demonstrates that the diarylmethane backbone represents a very promising molecular scaffold for the design of potent URAT1 inhibitors.

Identification of novel PPARα/γ dual agonists by virtual screening, ADMET prediction and molecular dynamics simulations.

PPARα and PPARγ have been the most widely studied Peroxisome proliferator-activated receptor (PPAR) subtypes due to their important roles in regulating glucose, lipids, and cholesterol metabolism. By combining the lowering serum triglyceride levels benefit of PPARα agonists (such as fibrates) with the glycemic advantages of the PPARγ agonists (such as TZD), the dual PPAR agonists approach can both improve the metabolic effects and minimize the side effects caused by either agent alone, and hence, has become a promising strategy for designing effective drugs against type-2 diabetes. In this study, by means of virtual screening, ADMET prediction and molecular dynamics (MD) simulations techniques, one compound-ASN15761007 with high binding score, low toxicity were gained. It was observed by MD simulations that ASN15761007 not only possessed the same function as AZ242 did in activating PPARα and BRL did in activating PPARγ, but also had more favorable conformation for binding to the two receptors. Our results provided an approach to rapidly produce novel PPARα/γ dual agonists which might be a potential lead compound to develop against insulin resistance and hyperlipidemia.

Glycyrrhetic Acid Derivative TY501 Protects Against Lithocholic Acid-Induced Cholestasis.

The aim of the study is to investigate the protective effects of TY501 against LCA-induced cholestasis in mice and to explore the potential mechanisms. It was demonstrated that TY501(5, 15 or 45 mg/kg, i.g.) can markedly reduced the level of ALT, AST and ALP which increased by LCA treatment. Meanwhile, TY501 also lowered total bile acids, total bilirubin and total cholesterol levels in serum. Furthermore, TY501 can protect HepG2 cell cultures from LCA-induced cytotoxicity. RT-PCR and Western Blot analysis showed that TY501 recovered the expression of BSEP, MRP2 and NTCP which were down-regulated by LCA. Moreover, mRNA and protein of FXR was also observed in TY501 treated mice significantly accumulation in nucleus. Taken together, It can be concluded that TY501 exerted beneficial effects on LCA-induced cholestasis, possibly via activation of FXR mediated upregulation of BSEP, MRP2 and NTCP.

Virtual identification of novel PPARα/γ dual agonists by scaffold hopping of saroglitazar.

The thiazolidinedione class PPARγ agonists as antidiabetic agents are restricted in clinical use because of the side effects such as edema, weight gain, and heart failure. The single and selective agonism of PPARγ is the main cause of side effects. The multi-target cooperative PPARα/γ dual agonist development is a hot topic in the antidiabetic medicinal chemistry field. Saroglitazar is the first approved PPARα/γ dual agonist, available in India for the treatment of diabetic dyslipidemia. It got rid of these side effects. With the aim of finding more protent PPARα/γ dual agonists, the scaffold hopping was used to replace α-o phenylpropionic acid skeleton of saroglitazar with L-tyrosine skeleton. Then, the structural modification was carried out designing 72 compounds. Considering the importance of chirality, opposite configuration of 72 compounds was also studied. 12 compounds with better -cdocker energy were screened by molecular docking. Subsequently, the pharmacokinetic properties and toxicity evaluated by ADMET prediction, 11 of them showed better properties. Comp#L-17-1 and comp#L-3-1 were regarded as representatives to study the binding stability by molecular dynamics (MD) simulations. The MD simulation results of comp#L-17-1-PPARs (α, γ) and comp#L-3-1-PPARs (α, γ) provided structure reference for the research and development of novel PPARα/γ dual agonists.

Comparative study on the interaction between 3 CYP2C9 allelic isoforms and benzbromarone by using LC-MS/MS method.

Benzbromarone is a uricosuric drug metabolized predominantly by cytochrome P450 2C9 from in vitro findings. Human CYP2C9 exhibits extensive genetic polymorphism and numbers of clinic studies have demonstrated that CYP2C9 genetic polymorphism has a significant influence on the pharmacokinetics of benzbromarone. But in vitro study on the interaction between CYP2C9 allelic isoforms and benzbromarone was rare. Here, an LC-MS/MS method was established and validated to determine the concentration of benzbromarone in different CYP2C9 enzyme incubation systems for the drug-enzyme interaction study. By selecting appropriate internal standard and optimizing separation system, including mobile phase, sample solvent and gradient elution condition, this LC-MS/MS method was developed with fine linearity (r2≥0.996), good reproducibility (RSD≤6.6%), high stability (92.37-114.67%), efficient recovery (91.23-109.82%) and acceptable matrix effect (110.54-115.31%). Based on this method, the interaction between 3 CYP2C9 allelic isoforms and benzbromarone was researched by kinetics parameters (Km, Vmax, Clint). As a result, CYP2C9*1 displayed the highest metabolic activity towards benzbromarone, CYP2C9*2 showed a little lower catalytic activity than CYP2C9*1 (relative clearance/*1=85.86%), CYP2C9*3 showed the lowest catalytic activity (relative clearance/*1=21.57%). The result illustrated that various CYP2C9 allelic isoforms showed different enzymatic activities towards benzbromarone, which could offer effective consultation for personalized administration in clinic.

Molecular docking, 3D-QSAR and structural optimization on imidazo-pyridine derivatives dually targeting AT1 and PPARg.

Telmisartan, a bifunctional agent of blood pressure lowering and glycemia reduction, was previously reported to antagonize angiotensin II type 1 (AT1) receptor and partially activate peroxisome proliferator-activated receptor γ (PPARγ) simultaneously. Through the modification to telmisartan, researchers designed and obtained imidazo-\pyridine derivatives with the IC50s of 0.49~94.1 nM against AT1 and EC50s of 20~3640 nM towards PPARγ partial activation. For minutely inquiring the interaction modes with the relevant receptor and analyzing the structure-activity relationships, molecular docking and 3D-QSAR (Quantitative structure-activity relationships) analysis of these imidazo-\pyridines on dual targets were conducted in this work. Docking approaches of these derivatives with both receptors provided explicit interaction behaviors and excellent matching degree with the binding pockets. The best CoMFA (Comparative Molecular Field Analysis) models exhibited predictive results of q2=0.553, r2=0.954, SEE=0.127, r2pred=0.779 for AT1 and q2=0.503, r2=1.00, SEE=0.019, r2pred=0.604 for PPARγ, respectively. The contour maps from the optimal model showed detailed information of structural features (steric and electrostatic fields) towards the biological activity. Combining the bioisosterism with the valuable information from above studies, we designed six molecules with better predicted activities towards AT1 and PPARγ partial activation. Overall, these results could be useful for designing potential dual AT1 antagonists and partial PPARγ agonists.

Synthesis and evaluation of anthranilamide-based derivatives as FXa inhibitors.

Factor Xa (FXa) plays a significant role in the blood coagulation cascade and is a promising target for anticoagulation drugs. Three oral FXa inhibitors have been approved by FDA for treating thrombotic diseases. In this study, 43 novel compounds were synthesized anthranilamide-based FXa inhibitors aiming to ameliorate the toxicity of traditional FXa inhibitors in clinic. The data indicated that the compounds 6a, 6a-b, 6a-e, 6k, 6k-a and 6k-b showed remarkable FXa inhibitory activity and excellent selectivity over thrombin in vitro. Selected compounds also exhibited anticoagulant activities in vitro consequently and were potent novel anti-coagulators in further.

Design, sythesis and evaluation of a series of 3- or 4-alkoxy substituted phenoxy derivatives as PPARs agonists.

Peroxisome proliferators-activated receptors (PPARα, γ and δ) are potentially effective targets for Type 2 diabetes mellitus therapy. The severe effects of known glitazones and the successfully approved agents (saroglitazar and lobeglitazone) motivated us to study novelly potent PPARs drugs with improved safety profile. In this work, we received 15 carboxylic acids based on the combination principle to integrate the polar head of bezafibrate with the hydrophobic tail of pioglitazone. Another 12 tetrazoles based on the bioisosterism principle were obtained accordingly. Furthermore, in vitro PPARs transactivation assays on these 3- or 4-alkoxy substituted phenoxy derivatives afforded six compounds. Interactions and binding stability from the docking analysis and 20 ns molecular dynamic simulations confirmed the representative compounds to be suitable and plausible for PPARs pockets. The above-mentioned results demonstrated that the compounds may be used as reference for further optimization for enhanced PPARs activities and wide safety range.

Discovery of Flexible Naphthyltriazolylmethane-based Thioacetic Acids as Highly Active Uric Acid Transporter 1 (URAT1) Inhibitors for the Treatment of Hyperuricemia of Gout.

BACKGROUND: Gout is the most common inflammatory arthritis, which, if left untreated or inadequately treated, will lead to joint destruction, bone erosion and disability due to the crystal deposition. Uric acid transporter 1 (URAT1) was the promising therapeutic target for urate-lowering therapy. OBJECTIVE: The goal of this work is to understand the structure-activity relationship (SAR) of a potent lesinurad-based hit, sodium 2-((5-bromo-4-((4-cyclopropyl-naphth-1-yl)methyl)-4H-1,2,4-triazol-3- yl)thio)acetate (1c), and based on that discover a more potent URAT1 inhibitor. METHODS: The SAR of 1c was systematically explored and the in vitro URAT1 inhibitory activity of synthesized compounds 1a-1t was determined by the inhibition of URAT1-mediated [8-14C]uric acid uptake by human embryonic kidney 293 (HEK293) cells stably expressing human URAT1. RESULTS: Twenty compounds 1a-1t were synthesized. SAR analysis was performed. Two highly active URAT1 inhibitors, sodium 2-((5-bromo-4-((4-n-propylnaphth-1-yl)methyl)-4H-1,2,4-triazol-3- yl)thio)acetate (1j) and sodium 2-((5-bromo-4-((4-bromonaphth-1-yl)methyl)-4H-1,2,4-triazol-3- yl)thio)acetate (1m), were identified, which were 78- and 76-fold more active than parent lesinurad in in vitro URAT1 inhibitory assay, respectively (IC50 values for 1j and 1m were 0.092 µM and 0.094 µM, respectively, against human URAT1 vs 7.18 µM for lesinurad). CONCLUSION: Two highly active URAT1 inhibitors were discovered. The SAR exploration also identified more flexible naphthyltriazolylmethane as a novel molecular skeleton that will be valuable for the design of URAT1 inhibitors, as indicated by the observation that many of the synthesized naphthyltriazolylmethane- bearing derivatives (1b-1d, 1g, 1j and 1m) showed significantly improved UART1 inhibitory activity (sub-micromolar IC50 values) as compared with lesinurad which has the rigid naphthyltriazole skeleton.