ABSTRACT
OBJECTIVE: Incretin receptor agonists are now standard of care in treating obesity. Their efficacy and tolerability might be further improved by combining them with compounds that offer orthogonal mechanisms of action. The cannabinoid type 1 receptor (CB1R) is a clinically validated therapeutic target in obesity, and several experimental CB1R inverse agonists have been shown to induce weight loss. METHODS: This study characterizes a novel CB1R inverse agonist (CRB-913) with similar preclinical potency to rimonabant but markedly reduced brain penetration. CRB-913 was tested as monotherapy and in combination with tirzepatide, semaglutide, or liraglutide in the diet-induced obesity (DIO) mouse model for body weight reduction. RESULTS: CRB-913 demonstrated enhanced plasma exposure (3.8-fold larger area under the curvelast ) and reduced brain levels (9.5-fold lower area under the curvelast ) than rimonabant. CRB-913 monotherapy yielded a dose-dependent decrease in body weight in DIO mice reaching -22% within 18 days. In further DIO studies in combination with tirzepatide, semaglutide, or liraglutide, CRB-913 (2.5 mg/kg) resulted in -32.6%, -28.8%, and -16.8% decreases in body weight on Day 18, respectively, with concomitant improvements in body fat content, liver triglycerides, and liver fat deposits. CONCLUSIONS: CRB-913 in combination with incretin analogues could deliver meaningful improvements over current standards of care for obesity and related conditions.
Subject(s)
Drug Inverse Agonism , Liraglutide , Mice , Animals , Rimonabant/pharmacology , Rimonabant/therapeutic use , Liraglutide/pharmacology , Liraglutide/therapeutic use , Incretins/therapeutic use , Obesity/drug therapy , Body Weight , Diet , Weight Loss , Receptors, Cannabinoid/therapeutic useABSTRACT
The effectiveness of controlled release 1-aminobenzotriazole (ABT) administration to inhibit cytochrome P450 (P450) enzymes has been evaluated in mice. To maximize the duration of P450 inhibition in vivo, ABT was administered via an osmotic pump. The degree of P450 inhibition was compared with that achieved with a single bolus dose of ABT. Two-hour prior subcutaneous treatment of mice with ABT (50 mg/kg) inhibited antipyrine clearance by 88%. A less pronounced inhibitory effect (29% reduction in clearance) was observed when ABT was administered 24-hours before antipyrine administration, indicating partial restoration of P450 activity during this longer pretreatment time. The duration of ABT in mice was very short (mean residence time = 1.7 hours) after subcutaneous bolus administration. When the inhibitor was delivered by an osmotic pump, maximum blood concentrations of the inhibitor were observed 24 hours after device implantation and were maintained at steady state for 6 days. Inhibition of P450 activity, as measured by antipyrine clearance, was confirmed at 24 hours and 120 hours after pump implantation, highlighting the utility of this method as a longer-term model for P450 inhibition in mice. The magnitude of P450 inhibition in ABT-treated mice was compared with that in hepatic P450 reductase null mice and both models were comparable. In vivo ABT administration by an osmotic pump offers an effective approach for longer-term P450 inhibition in mice and avoids the necessity for multiple dosing of the inhibitor.
Subject(s)
Antipyrine/pharmacokinetics , Cytochrome P-450 Enzyme Inhibitors/administration & dosage , Cytochrome P-450 Enzyme System/deficiency , Infusion Pumps, Implantable , Liver/drug effects , Triazoles/administration & dosage , Animals , Antipyrine/administration & dosage , Antipyrine/blood , Cytochrome P-450 Enzyme Inhibitors/blood , Cytochrome P-450 Enzyme System/genetics , Genotype , Infusions, Subcutaneous , Injections, Subcutaneous , Liver/enzymology , Male , Mice, Knockout , Osmotic Pressure , Phenotype , Triazoles/bloodABSTRACT
The successful launches of dipeptidyl peptidase IV (DPP IV) inhibitors as oral anti-diabetics warrant and spur the further quest for additional chemical entities in this promising class of therapeutics. Numerous pharmaceutical companies have pursued their proprietary candidates towards the clinic, resulting in a large body of published chemical structures associated with DPP IV. Herein, we report the discovery of a novel chemotype for DPP IV inhibition based on the C-(1-aryl-cyclohexyl)-methylamine scaffold and its optimization to compounds which selectively inhibit DPP IV at low-nM potency and exhibit an excellent oral pharmacokinetic profile in the rat.
Subject(s)
Dipeptidyl Peptidase 4/metabolism , Dipeptidyl-Peptidase IV Inhibitors/chemical synthesis , Dipeptidyl-Peptidase IV Inhibitors/pharmacokinetics , Drug Discovery , Methylamines/chemical synthesis , Methylamines/pharmacokinetics , Adamantane/analogs & derivatives , Adamantane/chemistry , Adamantane/pharmacology , Administration, Oral , Animals , Caco-2 Cells , Crystallography, X-Ray , Cyclization , Dipeptidyl-Peptidase IV Inhibitors/chemistry , Dipeptidyl-Peptidase IV Inhibitors/pharmacology , Enzyme Activation/drug effects , Humans , Inhibitory Concentration 50 , Methylamines/chemistry , Methylamines/pharmacology , Molecular Structure , Nitriles/chemistry , Nitriles/pharmacology , Pyrazines/chemistry , Pyrazines/pharmacology , Pyrrolidines/chemistry , Pyrrolidines/pharmacology , Rats , Sitagliptin Phosphate , Triazoles/chemistry , Triazoles/pharmacology , VildagliptinABSTRACT
We discovered a series of novel and potent thiazolylpyridinone-based SCD1 inhibitors based on a 2-aminothiazole HTS hit by replacing the amide bond with a pyridinone moiety. Compound 19 demonstrated good potency against SCD1 in vitro and in vivo. The mouse liver microsomal SCD1 in vitro potency for 19 was improved by more than 240-fold compared to the original HTS hit. Furthermore, 19 demonstrated a dose-dependent reduction of plasma desaturation index with an ED50 of 6.3 mg/kg. Compound 19 demonstrated high liver to plasma and liver to eyelid exposures, indicating preferential liver distribution. The preliminary toxicology study with compound 19 did not demonstrate adverse effects related to SCD1 inhibition, suggesting a wide safety margin with respect to other known SCD1 inhibitors with wider distribution profiles.
Subject(s)
Drug Discovery/methods , Liver/metabolism , Pyridones/metabolism , Pyridones/pharmacology , Stearoyl-CoA Desaturase/antagonists & inhibitors , Stearoyl-CoA Desaturase/metabolism , Animals , Caco-2 Cells , Dose-Response Relationship, Drug , Hep G2 Cells , Humans , Liver/drug effects , Mice , Pyridones/chemistry , Rats , Rats, Inbred Lew , Tissue Distribution/drug effects , Tissue Distribution/physiologyABSTRACT
Susceptibility to metabolism is a common issue with the tert-butyl group on compounds of medicinal interest. We demonstrate an approach of removing all the fully sp(3) C-Hs from a tert-butyl group: replacing some C-Hs with C-Fs and increasing the s-character of the remaining C-Hs. This approach gave a trifluoromethylcyclopropyl group, which increased metabolic stability. Trifluoromethylcyclopropyl-containing analogues had consistently higher metabolic stability in vitro and in vivo compared to their tert-butyl-containing counterparts.
ABSTRACT
1-[4-Aminomethyl-4-(3-chlorophenyl)-cyclohexyl]-tetrahydro-pyrimidin- 2-one, 1, was developed as an inhibitor of dipeptidyl peptidase-4 enzyme. Biotransformation studies with 1 revealed the presence of an N-carbamoyl glucuronide metabolite (M1) in rat bile and urine. N-Carbamoyl glucuronides are rarely observed, and little is understood regarding the mechanism of N-carbamoyl glucuronidation. The objectives of the current investigation were to elucidate the structure of the novel N-carbamoyl glucuronide, to investigate the mechanism of N-carbamoyl glucuronide formation in vitro using stable labeled CO(2), UDP glucuronosyltransferase (UGT) reaction phenotyping, and to assess whether M1 was formed to the same extent in vitro across species-mouse, rat, hamster, dog, monkey, and human. Structure elucidation was performed on a mass spectrometer with accurate mass measurement and MS(n) capabilities. (13)C-labeled carbon dioxide was used for identification of the mechanism of N-carbamoyl glucuronidation. Mechanistic studies with (13)C-labeled CO(2) in rat liver microsomes revealed that CO(2) from the bicarbonate buffer (in equilibrium with exogenous CO(2)) may be responsible for the formation of M1. M1 was formed in vitro in liver microsomes from multiple species, mainly rat and hamster, followed by similar formation in dog, monkey, mouse, and human. M1 could be detected in UGT1A1, UGT1A3, and UGT2B7 Supersomes in a CO(2)-rich environment. In conclusion, our study demonstrates that formation of M1 was observed in microsomal incubations across various species and strongly suggests incorporation of CO(2) from the bicarbonate buffer, in equilibrium with exogenous CO(2), into the carbamoyl moiety of the formed N-carbamoyl glucuronide.
Subject(s)
Carbamates/chemistry , Carbamates/metabolism , Dipeptidyl-Peptidase IV Inhibitors , Enzyme Inhibitors/pharmacokinetics , Glucuronides/biosynthesis , Glucuronides/chemistry , Glucuronides/metabolism , Pyrimidinones/chemistry , Pyrimidinones/metabolism , Animals , Bile/chemistry , Biotransformation , Carbamates/urine , Diabetes Mellitus, Type 2/drug therapy , Enzyme Inhibitors/metabolism , Glucuronides/urine , Glucuronosyltransferase/metabolism , Humans , Isoenzymes/metabolism , Male , Microsomes, Liver/enzymology , Microsomes, Liver/metabolism , Molecular Structure , Pyrimidinones/pharmacokinetics , Pyrimidinones/urine , Rats , Rats, Sprague-Dawley , Species Specificity , Spectrometry, Mass, Electrospray Ionization , Tandem Mass Spectrometry , Urine/chemistryABSTRACT
We report the design and synthesis of a series of 6-(2,4-diaminopyrimidinyl)-1,4-benzoxazin-3-ones as orally bioavailable small molecule inhibitors of renin. Compounds with a 2-methyl-2-aryl substitution pattern exhibit potent renin inhibition and good permeability, solubility, and metabolic stability. Oral bioavailability was found to be dependent on metabolic clearance and cellular permeability, and was optimized through modulation of the sidechain that binds in the S3(sp) subsite.
Subject(s)
Benzoxazines/chemistry , Benzoxazines/pharmacology , Drug Design , Pyridines/chemistry , Renin/antagonists & inhibitors , Amination , Animals , Benzoxazines/chemical synthesis , Benzoxazines/metabolism , Crystallography, X-Ray , Male , Models, Molecular , Molecular Structure , Rats , Rats, Sprague-Dawley , Renin/chemistry , Renin/metabolism , Structure-Activity RelationshipABSTRACT
Novel 2,4-diaminopyrimidine-based small molecule renin inhibitors are disclosed. Through high throughput screening, parallel synthesis, X-ray crystallography, and structure based drug design, we have developed the first non-chiral, non-peptidic, small molecular template to possess moderate potency against renin. The designed compounds consist of a novel 6-ethyl-5-(1,2,3,4-tetrahydroquinolin-7-yl)pyrimidine-2,4-diamine ring system that exhibit moderate potency (IC(50): 91-650 nM) against renin while remaining 'Rule-of-five' compliant.