ABSTRACT
Novel pyrrole derivatives were discovered as potent agonists of the niacin receptor, GPR109A. During the derivatization, compound 16 was found to be effective both in vitro and in vivo. The compound 16 exhibited a significant reduction of the non-esterified fatty acid in human GPR109A transgenic rats, and the duration of its in vivo efficacy was much longer than niacin.
Subject(s)
Nicotinic Agonists/chemistry , Pyrroles/chemistry , Receptors, G-Protein-Coupled/agonists , Animals , Drug Design , Fatty Acids, Nonesterified/metabolism , Humans , Lipolysis/drug effects , Nicotinic Agonists/metabolism , Nicotinic Agonists/pharmacology , Pyrroles/metabolism , Pyrroles/pharmacology , Rats , Rats, Transgenic , Receptors, G-Protein-Coupled/metabolism , Structure-Activity RelationshipABSTRACT
Expansion of the 6-membered ring and subsequent fine-tuning of the newly obtained 7-membered spiropiperidine structure resulted in the discovery of a series of novel and potent SCD1 inhibitors. Preliminary SAR was explored by modifying an alkyl chain on the azepine nitrogen and resulted in the identification of a highly potent SCD1 inhibitor: 6-[5-(cyclopropylmethyl)-4,5-dihydro-1'H,3H-spiro[1,5-benzoxazepine-2,4'-piperidin]-1'-yl]-N-(2-hydroxy-2-pyridin-3-ylethyl)pyridazine-3-carboxamide (9). Compound 9 exhibited an IC(50) value of 0.01 µM against human SCD1.
Subject(s)
Drug Discovery , Enzyme Inhibitors/pharmacology , Piperidines/pharmacology , Spiro Compounds/pharmacology , Stearoyl-CoA Desaturase/antagonists & inhibitors , Animals , Enzyme Activation/drug effects , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , HEK293 Cells , Humans , Mice , Molecular Structure , Piperidines/chemical synthesis , Piperidines/chemistry , Spiro Compounds/chemical synthesis , Spiro Compounds/chemistry , Stearoyl-CoA Desaturase/metabolism , Stereoisomerism , Structure-Activity RelationshipABSTRACT
In continuation of our investigation on novel stearoyl-CoA desaturase (SCD) 1 inhibitors, we have already reported on the structural modification of the benzoylpiperidines that led to a series of novel and highly potent spiropiperidine-based SCD1 inhibitors. In this report, we would like to extend the scope of our previous investigation and disclose details of the synthesis, SAR, ADME, PK, and pharmacological evaluation of the spiropiperidines with high potency for SCD1 inhibition. Our current efforts have culminated in the identification of 5-fluoro-1'-{6-[5-(pyridin-3-ylmethyl)-1,3,4-oxadiazol-2-yl]pyridazin-3-yl}-3,4-dihydrospiro[chromene-2,4'-piperidine] (10e), which demonstrated a very strong potency for liver SCD1 inhibition (ID(50)=0.6 mg/kg). This highly efficacious inhibition is presumed to be the result of a combination of strong enzymatic inhibitory activity (IC(50) (mouse)=2 nM) and good oral bioavailability (F >95%). Pharmacological evaluation of 10e has demonstrated potent, dose-dependent reduction of the plasma desaturation index in C57BL/6J mice on a high carbohydrate diet after a 7-day oral administration (q.d.). In addition, it did not cause any noticeable skin abnormalities up to the highest dose (10 mg/kg).
Subject(s)
Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Pyridines/chemical synthesis , Pyridines/pharmacology , Stearoyl-CoA Desaturase/antagonists & inhibitors , Animals , Drug Evaluation, Preclinical , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacokinetics , Magnetic Resonance Spectroscopy , Mice , Mice, Inbred C57BL , Pyridines/chemistry , Pyridines/pharmacokinetics , Spectrometry, Mass, Electrospray Ionization , Structure-Activity RelationshipABSTRACT
Starting from a known piperazine-based SCD-1 inhibitor, we obtained more potent benzoylpiperidine analogs. Optimization of the structure of the benzoylpiperidine-based SCD-1 inhibitors resulted in the identification of 6-[4-(2-methylbenzoyl)piperidin-1-yl]pyridazine-3-carboxylic acid (2-hydroxy-2-pyridin-3-yl-ethyl)amide (24) which showed strong inhibitory activity against both human and murine SCD-1. In addition, this compound exhibited good oral bioavailability and demonstrated plasma triglyceride lowering effects in Zucker fatty rats in a dose-dependent manner after a 7-day oral administration (qd).
Subject(s)
Enzyme Inhibitors/chemistry , Hypoglycemic Agents/chemistry , Piperidines/chemistry , Pyridazines/chemistry , Pyridines/chemistry , Stearoyl-CoA Desaturase/antagonists & inhibitors , Triglycerides/blood , Administration, Oral , Animals , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacokinetics , Humans , Hypoglycemic Agents/chemical synthesis , Hypoglycemic Agents/pharmacokinetics , Mice , Microsomes, Liver/metabolism , Piperidines/chemical synthesis , Piperidines/pharmacokinetics , Pyridazines/chemical synthesis , Pyridazines/pharmacology , Pyridines/chemical synthesis , Pyridines/pharmacology , Rats , Rats, Zucker , Stearoyl-CoA Desaturase/metabolismABSTRACT
Cyclization of the benzoylpiperidine in lead compound 2 generated a series of novel and highly potent spiropiperidine-based stearoyl-CoA desaturase (SCD)-1 inhibitors. Among them, 1'-{6-[5-(pyridin-3-ylmethyl)-1,3,4-oxadiazol-2-yl]pyridazin-3-yl}-5-(trifluoromethyl)-3,4-dihydrospiro[chromene-2,4'-piperidine] (19) demonstrated the most powerful inhibitory activity against SCD-1, not only in vitro but also in vivo (C57BL/6J mice). With regard to the pharmacological evaluation, 19 showed powerful reduction of the desaturation index in the plasma of C57BL/6J mice on a non-fat diet after a 7-day oral administration (q.d.) without causing notable abnormalities in the eyes or skin up to the highest dose (3mg/kg) in our preliminary analysis.
Subject(s)
Benzopyrans/chemical synthesis , Piperidines/chemical synthesis , Stearoyl-CoA Desaturase/antagonists & inhibitors , Administration, Oral , Animals , Benzopyrans/chemistry , Benzopyrans/pharmacokinetics , Cell Line, Tumor , Humans , Mice , Mice, Inbred C57BL , Microsomes, Liver/metabolism , Piperidines/chemistry , Piperidines/pharmacokinetics , Stearoyl-CoA Desaturase/metabolismABSTRACT
A series of structurally novel stearoyl-CoA desaturase-1 (SCD-1) inhibitors has been identified by optimizing a hit from our corporate library. Preliminary structure-activity relationship (SAR) studies led to the discovery of the highly potent and orally bioavailable thiazole-based SCD-1 inhibitor, 3-(2-hydroxyethoxy)-4-methoxy-N-[5-(3-trifluoromethylbenzyl)thiazol-2-yl]benzamide (23a).
Subject(s)
Benzamides/chemical synthesis , Chemistry, Pharmaceutical/methods , Enzyme Inhibitors/chemical synthesis , Stearoyl-CoA Desaturase/antagonists & inhibitors , Thiazoles/chemical synthesis , Administration, Oral , Animals , Area Under Curve , Benzamides/pharmacology , Drug Design , Enzyme Inhibitors/pharmacology , Humans , Inhibitory Concentration 50 , Mice , Mice, Inbred C57BL , Models, Chemical , Stearoyl-CoA Desaturase/chemistry , Structure-Activity Relationship , Thiazoles/chemistry , Thiazoles/pharmacologyABSTRACT
The continuing investigation of SAR studies of 3-(2-hydroxyethoxy)-N-(5-benzylthiazol-2-yl)-benzamides as stearoyl-CoA desaturase-1 (SCD-1) inhibitors is reported. Our prior hit-to-lead effort resulted in the identification of 1a as a potent and orally efficacious SCD-1 inhibitor. Further optimization of the structural motif resulted in the identification of 4-ethylamino-3-(2-hydroxyethoxy)-N-[5-(3-trifluoromethylbenzyl)thiazol-2-yl]benzamide (37c) with sub nano molar IC(50) in both murine and human SCD-1 inhibitory assays. This compound demonstrated a dose-dependent decrease in the plasma desaturation index in C57BL/6J mice on a non-fat diet after 7 days of oral administration.
Subject(s)
Benzamides/chemical synthesis , Chemistry, Pharmaceutical/methods , Stearoyl-CoA Desaturase/antagonists & inhibitors , Thiazoles/chemical synthesis , Administration, Oral , Animals , Area Under Curve , Benzamides/pharmacology , Dose-Response Relationship, Drug , Drug Design , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Humans , Inhibitory Concentration 50 , Mice , Mice, Inbred C57BL , Models, Chemical , Stearoyl-CoA Desaturase/chemistry , Structure-Activity Relationship , Thiazoles/chemistry , Thiazoles/pharmacologyABSTRACT
Quinazolinone type alkaloids, febrifugine (1) and isofebrifugine (2), isolated from Dichroa febrifuga roots, show powerful antimalarial activity against Plasmodium falciparum. Unfortunately, their emetic effect and other undesirable side effects have precluded their clinical use for malaria. Because of their antimalarial potency, analogues were searched for, with the goal of preserving the strong antimalarial activity, while dramatically reducing side effects. We expected that compounds useful in drug development would exist in metabolites derived from 1 and Df-1 (3), the condensation product of 1 with acetone, by mouse liver S9. Feb-A and -B (4 and 5) were isolated as the major metabolites of 1. In addition to 4 and 5, feb-C and -D (6 and 7) were also purified from the metabolic mixture of 3. Compounds 4 and 5 were compounds oxidized at C-6 and C-2 of the quinazolinone ring of 1, respectively. Compounds 6 and 7, derived from 3, also bear febrifugine type structures in which the 4' '- and 6' '-positions of the piperidine ring of 1 were oxidized. In vitro antimalarial and cytotoxic tests using synthetically obtained racemic 4-6 and enantiomerically pure 7 demonstrated that 4 and 6 had antimalarial activity against P. falciparum, of similar potency to that of 1, with high selectivity. The antimalarial activity of 5 and 7, however, was dramatically decreased in the test. The in vitro antimalarial activity of analogues 22 and 43, which are stereoisomers of 4 and 6, was also evaluated, showing that 22 is active. The results suggest that basicity of both the 1- and the 1' '-nitrogen atoms of 1 is crucial in conferring powerful antimalarial activity. Racemic 4 and 6 exhibited powerful in vivo antimalarial activity against mouse malaria P. berghei, and especially, no serious side effects were observed with 4. Thus, the metabolite 4 appears to be a promising lead compound for the development of new types of antimalarial drugs.