Hypoxia-inducible factor (HIF) inhibitors: a patent survey (2016-2020).

: Hypoxia-inducible factor (HIF) is a master regulator of oxygen homeostasis. The increased expression of genes targeted by HIF is associated with many human diseases, including ischemic cardiovascular disease, stroke, chronic lung disease, and cancer.: This patent survey summarizes the information about patented HIF inhibitors over the last 5 years.

1, 2-Benzisoxazole: A Privileged Structure with a Potential for Polypharmacology.

Background: Privileged structures are potentially able to bind to a diverse range of biologically important proteins with high affinities, thus benefiting the discovery of novel bioactive compounds. 1,2-Benxisoxazole derivatives can be such important types of "privileged structures" possessing a rich diversity of biological properties especially in the area of CNS disorders.

Methods: This review seeks to explore the most significant examples of 1,2-benzisoxazoles as privileged structures in terms of polypharmacology at the molecular level, specifically focusing on four 1,2-benzisoxazoles (zonisamide, risperidone, paliperidone, and iloperidone) which have been in clinical use and established as effective therapeutics.

Hypoxia-inducible factor (HIF) inhibitors: a patent survey (2011-2015).

Introduction: Hypoxia-inducible factor (HIF)-1α regulates the expression of genes involved in angiogenesis, cellular energy metabolism, and cell survival during cancer development. The increased expression of HIF-1α in most solid tumors is associated with poor prognoses and therapeutic outcomes. Therefore, HIF has been recognized as an attractive target for cancer therapy, and many HIF inhibitors have been reported.

Recent progress in the discovery and development of stearoyl CoA desaturase inhibitors.

Stearoyl-CoA desaturase 1 (SCD1) is a rate-limiting enzyme in the biosynthesis of monounsaturated fatty acids from their saturated fatty acid precursors. SCD1 introduces a cis-double bond at the Δ9 position (between carbons 9 and 10) of stearoyl (C18:0) and palmitoyl-CoA (C16:0). SCD1 has been shown to be a crucial factor in lipid metabolism and body weight control.

1,2-Benzisoxazole compounds: a patent review (2009 - 2014).

Introduction: Benzisoxazoles represent a class of heterocyclic compounds of great importance for the preparation of biologically active compounds. Benzisoxazoles are an important structure and some benzisoxazole-based medicines have been approved for human clinical use, including atypical antipsychotics (risperidone, paliperidone and iloperidone) and an anticonvulsant (zonisamide).

Areas Covered: This review puts emphasis on the recent progress in therapeutically attractive benzisoxazole derivatives especially 1,2-benzisoxazoles, which were published in the patent literature between 2009 and 2014.

Imidazo[1,2-a]pyridines as cholesterol 24-hydroxylase (CYP46A1) inhibitors: a patent evaluation (WO2014061676).

A series of imidazo[1,2-a]pyridine analogs that effectively inhibit cholesterol 24-hydroxylase (CYP46A1) was reported in WO2014061676. The treatment or prophylaxis of neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease, by these novel CYP46A1 inhibitors is claimed in the patent. These compounds represent a novel pharmacophore that is different from other structural motifs described in the prior patent publications by Takeda Pharmaceutical Company Ltd.

A novel inhibitor of stearoyl-CoA desaturase-1 attenuates hepatic lipid accumulation, liver injury and inflammation in model of nonalcoholic steatohepatitis.

Stearoyl-CoA desaturase-1 (SCD-1) catalyzes the biosynthesis of monounsaturated fatty acids, and their abnormality is possibly responsible for obesity, insulin resistance, hepatic steatosis and nonalcoholic steatohepatitis (NASH). A novel SCD-1 inhibitor, N-(2-hydroxy-2-phenylethyl)-6-[4-(2-methylbenzoyl)piperidin-1-yl]pyridazine-3-carboxamide, has been obtained. The compound inhibited liver SCD-1 activity and increased liver triglyceride accumulation in mice fed with non-fat, high-sucrose diets.

Benzisoxazole analogs as glycogen synthase activators, a patent evaluation (WO2011057956).

A small series of benzisoxazole analogs that effectively activate glycogen synthase (GS) was prepared in WO2011057956. These novel GS activators are claimed to be beneficial for the treatment or prophylaxis of metabolic disease and disorders. The 1,2-benzisoxazole-3-ol moiety is utilized in the present patent as a bioisoster of benzoic acid, which has often been employed in prior examples of the GS activators.

Piperidine and pyrrolidine analogs as glycogen synthase activators; a patent evaluation (WO2011058122).

A small series of piperidine analogs that effectively activate glycogen synthase (GS) was prepared in WO2011058122. The treatment or prophylaxis of metabolic disease and disorders by these novel GS activators is claimed. These compounds represent further variations around a structural motif explored in the prior patent publications by Roche.

Discovery of novel SCD1 inhibitors: 5-alkyl-4,5-dihydro-3H-spiro[1,5-benzoxazepine-2,4'-piperidine] analogs.

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.

Hypoxia-inducible factor inhibitors: a survey of recent patented compounds (2004 - 2010).

Introduction: Hypoxia-inducible factor (HIF) is a heterodimeric transcription factor consisting of α and β subunits that regulates the expression of angiogenic factors, including VEGF, which are involved in angiogenesis, invasion/metastasis, glucose uptake and cell survival during cancer development.

Areas Covered: This review summarizes the information about patented HIF inhibitors over the last 7 years (2004 - 2010). The reader will gain an outline of the structure and biological activity of recently developed HIF inhibitors.

Synthesis and evaluation of novel stearoyl-CoA desaturase 1 inhibitors: 1'-{6-[5-(pyridin-3-ylmethyl)-1,3,4-oxadiazol-2-yl]pyridazin-3-yl}-3,4-dihydrospiro[chromene-2,4'-piperidine] analogs.

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.

Novel spiropiperidine-based stearoyl-CoA desaturase-1 inhibitors: Identification of 1'-{6-[5-(pyridin-3-ylmethyl)-1,3,4-oxadiazol-2-yl]pyridazin-3-yl}-5-(trifluoromethyl)-3,4-dihydrospiro[chromene-2,4'-piperidine].

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.

Novel benzoylpiperidine-based stearoyl-CoA desaturase-1 inhibitors: Identification of 6-[4-(2-methylbenzoyl)piperidin-1-yl]pyridazine-3-carboxylic acid (2-hydroxy-2-pyridin-3-ylethyl)amide and its plasma triglyceride-lowering effects in Zucker fatty rats.

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).

Novel and potent inhibitors of stearoyl-CoA desaturase-1. Part II: Identification of 4-ethylamino-3-(2-hydroxyethoxy)-N-[5-(3-trifluoromethylbenzyl)thiazol-2-yl]benzamide and its biological evaluation.

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.

Novel and potent inhibitors of stearoyl-CoA desaturase-1. Part I: Discovery of 3-(2-hydroxyethoxy)-4-methoxy-N-[5-(3-trifluoromethylbenzyl)thiazol-2-yl]benzamide.

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).

Total synthesis of a stereoisomer of bistramide C and assignment of configuration of the natural product.

After the isolation of the bioactive polyether bistramide C from the marine ascidian Lissoclinum bistratum in 1988, NMR spectroscopic investigations over the next 12 years reduced the total number of possible stereoisomers of this compound from 1024 to 32. Based on the preparation of segments of the natural product as well as the total synthesis of a randomly selected stereoisomer of bistramide C, the stereochemical puzzle could be further simplified to eight possible stereoisomers. A convergent three-segment coupling strategy, the use of a common, D-glucose-derived intermediate for the preparation of pyran rings in two segments, a stereoselective photo-spiroketalization, and the use of azides to minimize protective group manipulations before segment couplings are highlights of the synthetic approach.