Synthesis of Potent and Orally Efficacious 11β-Hydroxysteroid Dehydrogenase Type 1 Inhibitor HSD-016

Progress in 11β-HSD1 inhibitors for the treatment of metabolic diseases: A comprehensive guide to their chemical structure diversity in drug development

11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) is a key metabolic enzyme that catalyzing the intracellular conversion of inactive glucocorticoids to physiologically active ones. Work over the past decade has demonstrated the aberrant overexpression of 11β-HSD1 contributed to the pathophysiological process of metabolic diseases like obesity, type 2 diabetes mellitus, and metabolic syndromes. The inhibition of 11β-HSD1 represented an attractive therapeutic strategy for the treatment of metabolic diseases. Therefore, great efforts have been devoted to developing 11β-HSD1 inhibitors based on the diverse molecular scaffolds. This review focused on the structural features of the most important 11β-HSD1 inhibitors and categorized them into natural products derivatives and synthetic compounds. We also briefly discussed the optimization process, binding modes, structure-activity relationships (SAR) and biological evaluations of each inhibitor. Moreover, the challenges and directions for 11β-HSD1 inhibitors were discussed, which might provide some useful clues to guide the future discovery of novel 11β-HSD1 inhibitors.

Discovery and Biological Evaluation of Potent and Orally Active Human 11β-Hydroxysteroid Dehydrogenase Type 1 Inhibitors for the Treatment of Type 2 Diabetes Mellitus

We synthesized and evaluated novel 5-[2-(thiophen-2-yl)propan-2-yl]-4H-1,2,4-triazole derivatives as 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) inhibitors. Optimization of the thiophene ring and the substituents on the 1,2,4-triazole ring produced 3,4-dicyclopropyl-5-{2-[3-fluoro-5-(trifluoromethyl)thiophen-2-yl]propan-2-yl}-4H-1,2,4-triazole monohydrochloride (9a), which showed potent and selective inhibitory activity against human 11β-HSD1. Compound 9a was also metabolically stable against human and mouse liver microsomes. Oral administration of 9a to diabetic ob/ob mice lowered corticosterone levels in adipose tissue, and thereby reduced plasma glucose and insulin levels in a dose-dependent manner.

Palladium-Catalyzed Negishi Coupling of α-CF3 Oxiranyl Zincate: Access to Chiral CF3-Substituted Benzylic Tertiary Alcohols

We report a Pd-catalyzed stereospecific α-arylation of optically pure 2,3-epoxy-1,1,1-trifluoropropane (TFPO). This method allows for the direct and reliable preparation of optically pure 2-CF₃-2-(hetero)aryloxiranes, which are precursors to many CF₃-substituted tertiary alcohols. The use of continuous-flow methods has allowed the deprotonation of TFPO and subsequent zincation at higher temperature compared to that under traditional batch conditions.

Development of an Intermittent-Flow Enantioselective Aza-Henry Reaction Using an Arylnitromethane and Homogeneous Brønsted Acid-Base Catalyst with Recycle

A stereoselective aza-Henry reaction between an arylnitromethane and Boc-protected aryl aldimine using a homogeneous Brønsted acid-base catalyst was translated from batch format to an automated intermittent-flow process. This work demonstrates the advantages of a novel intermittent-flow setup with product crystallization and slow reagent addition which is not amenable to the standard continuous equipment: plug flow tube reactor (PFR) or continuous stirred tank reactor (CSTR). A significant benefit of this strategy was the integration of an organocatalytic enantioselective reaction with straightforward product separation, including recycle of the catalyst, resulting in increased intensity of the process by maintaining high catalyst concentration in the reactor. A continuous campaign confirmed that these conditions could effectively provide high throughput of material using an automated system while maintaining high selectivity, thereby addressing nitroalkane safety and minimizing catalyst usage.

Pharmacokinetic characterization of 2-(3-benzoyl)-4-hydroxy-1,1-dioxo-2H-1,2-benzothiazine-2-yl-1-phenylethanone, a novel 11β-hydroxysteroid dehydrogenase type 1 inhibitor in rats

11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) is associated with metabolic syndromes such as type 2 diabetes mellitus and obesity. A new 11β-HSD1 inhibitor known as 2-(3-benzoyl)-4-hydroxy-1, 1-dioxo-2H-1, 2-benzothiazine-2-yl-1-phenylethanone (KR-66344) is being developed as a therapeutic agent for these metabolic diseases. The purpose of this study was to characterize the pharmacokinetics of KR-66344 to support further preclinical development. KR-66344 showed high liver microsomal stability with T1/2 values >3 h and high permeability with apparent permeability coefficients of 15.2-24.2 × 10(-6) cm/s in Caco-2 cell monolayers. KR-66344 was also strongly bound to plasma proteins (>98%). After intravenous dosing, KR-66344 exhibited low systemic clearance (0.27-0.37 L/h/kg) and a low to moderate volume of distribution at steady state (0.79-0.8 L/kg). The bioavailability and terminal half-lives of KR-66344 following oral administration were 25% and 1.7-3.3 h, respectively. In addition, KR-66344 showed dose-independent pharmacokinetics at 0.5-10 mg/kg in intravenous and oral pharmacokinetic studies.

Flow trifluoromethylation of carbonyl compounds by Ruppert–Prakash reagent and its application for pharmaceuticals, efavirenz and HSD-016

Flow trifluoromethylation of carbonyl compounds using the Ruppert–Prakash reagent, Me₃SiCF₃ is disclosed including enantioselective trifluoromethylation. Synthesis of pharmaceuticals, efavirenz and HSD-016 were achieved by this flow method.

Brain mineralocorticoid receptors in cognition and cardiovascular homeostasis

Mineralocorticoid receptors (MR) mediate diverse functions supporting osmotic and hemodynamic homeostasis, response to injury and inflammation, and neuronal changes required for learning and memory. Inappropriate MR activation in kidneys, heart, vessels, and brain hemodynamic control centers results in cardiovascular and renal pathology and hypertension. MR binds aldosterone, cortisol and corticosterone with similar affinity, while the glucocorticoid receptor (GR) has less affinity for cortisol and corticosterone. As glucocorticoids are more abundant than aldosterone, aldosterone activates MR in cells co-expressing enzymes with 11β-hydroxydehydrogenase activity to inactivate them. MR and GR co-expressed in the same cell interact at the molecular and functional level and these functions may be complementary or opposing depending on the cell type. Thus the balance between MR and GR expression and activation is crucial for normal function. Where 11β-hydroxydehydrogenase 2 (11β-HSD2) that inactivates cortisol and corticosterone in aldosterone target cells of the kidney and nucleus tractus solitarius (NTS) is not expressed, as in most neurons, MR are activated at basal glucocorticoid concentrations, GR at stress concentrations. An exception may be pre-autonomic neurons of the PVN which express MR and 11β-HSD1 in the absence of hexose-6-phosphate dehydrogenase required to generate the requisite cofactor for reductase activity, thus it acts as a dehydrogenase. MR antagonists, valuable adjuncts to the treatment of cardiovascular disease, also inhibit MR in the brain that are crucial for memory formation and exacerbate detrimental effects of excessive GR activation on cognition and mood. 11β-HSD1 inhibitors combat metabolic and cognitive diseases related to glucocorticoid excess, but may exacerbate MR action where 11β-HSD1 acts as a dehydrogenase, while non-selective 11β-HSD1&2 inhibitors cause injurious disruption of MR hemodynamic control. MR functions in the brain are multifaceted and optimal MR:GR activity is crucial. Therefore selectively targeting down-stream effectors of MR specific actions may be a better therapeutic goal.

The multifaceted mineralocorticoid receptor

The primary adrenal cortical steroid hormones, aldosterone, and the glucocorticoids cortisol and corticosterone, act through the structurally similar mineralocorticoid (MR) and glucocorticoid receptors (GRs). Aldosterone is crucial for fluid, electrolyte, and hemodynamic homeostasis and tissue repair; the significantly more abundant glucocorticoids are indispensable for energy homeostasis, appropriate responses to stress, and limiting inflammation. Steroid receptors initiate gene transcription for proteins that effect their actions as well as rapid non-genomic effects through classical cell signaling pathways. GR and MR are expressed in many tissues types, often in the same cells, where they interact at molecular and functional levels, at times in synergy, others in opposition. Thus the appropriate balance of MR and GR activation is crucial for homeostasis. MR has the same binding affinity for aldosterone, cortisol, and corticosterone. Glucocorticoids activate MR in most tissues at basal levels and GR at stress levels. Inactivation of cortisol and corticosterone by 11β-HSD2 allows aldosterone to activate MR within aldosterone target cells and limits activation of the GR. Under most conditions, 11β-HSD1 acts as a reductase and activates cortisol/corticosterone, amplifying circulating levels. 11β-HSD1 and MR antagonists mitigate inappropriate activation of MR under conditions of oxidative stress that contributes to the pathophysiology of the cardiometabolic syndrome; however, MR antagonists decrease normal MR/GR functional interactions, a particular concern for neurons mediating cognition, memory, and affect.

Identification of novel 11β-HSD1 inhibitors by combined ligand- and structure-based virtual screening

11 beta-hydroxysteroid dehydrogenase type 1 (11β-HSD1) converts cortisone to cortisol in a NADPH dependent manner. Overexpression of 11β-HSD1 in key metabolic tissues is related to the development of type 2 diabetes, obesity, hypertension and metabolic syndrome. Using crystal structures of human 11β-HSD1 in complex with inhibitors as source of structural information, a combined ligand and structure-based virtual screening approach was implemented to identify novel 11β-HSD1 inhibitors. A selected group of compounds was identified in silico and further evaluated in cell-based assays for cytotoxicity and 11β-HSD1 mediated cortisol production inhibitory capacity. The expression of 11β-HSD1 and 11β-HSD2 in human LS14 adipocytes was assessed during differentiation. Biological evaluation of 39 compounds in adipocytes and steroids quantification by HPLC-MS/MS identify 4 compounds that exhibit 11β-HSD1 mediated cortisol production inhibitory activity with potencies in the micromolar range. Two compounds showed to be selective for the 11β-HSD1 reductase activity and over 11β-HSD2 isoform, and thus represent novel leads for the development of more active derivatives with higher efficacies targeting intracellular cortisol levels in type 2 diabetes and metabolic syndrome.

11β-Hydroxysteroid dehydrogenase 1: translational and therapeutic aspects

11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) interconverts the inactive glucocorticoid cortisone and its active form cortisol. It is widely expressed and, although bidirectional, in vivo it functions predominantly as an oxoreductase, generating active glucocorticoid. This allows glucocorticoid receptor activation to be regulated at a prereceptor level in a tissue-specific manner. In this review, we will discuss the enzymology and molecular biology of 11β-HSD1 and the molecular basis of cortisone reductase deficiencies. We will also address how altered 11β-HSD1 activity has been implicated in a number of disease states, and we will explore its role in the physiology and pathologies of different tissues. Finally, we will address the current status of selective 11β-HSD1 inhibitors that are in development and being tested in phase II trials for patients with the metabolic syndrome. Although the data are preliminary, therapeutic inhibition of 11β-HSD1 is also an exciting prospect for the treatment of a variety of other disorders such as osteoporosis, glaucoma, intracranial hypertension, and cognitive decline.

1,1-Dioxo-5,6-dihydro-[4,1,2]oxathiazines, a novel class of 11ß-HSD1 inhibitors for the treatment of diabetes

Racemic cis-1,1-dioxo-5,6-dihydro-[4,1,2]oxathiazine derivative 4a was isolated as an impurity in a sample of a hit from a HTS campaign on 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1). After separation by chiral chromatography the 4a-S, 8a-R enantiomer of compound 4a was identified as the true, potent enzyme inhibitor. The cocrystal structure of 4a with human and murine 11ß-HSD1 revealed the unique binding mode of the oxathiazine series. SAR elucidation and optimization in regard to metabolic stability led to monocyclic tetramethyloxathiazines as exemplified by compound 21g.

Discovery of HSD-621 as a Potential Agent for the Treatment of Type 2 Diabetes

11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) catalyzes the conversion of inactive glucocorticoid cortisone to its active form, cortisol. The glucocorticoid receptor (GR) signaling pathway has been linked to the pathophysiology of diabetes and metabolic syndrome. Herein, the structure-activity relationship of a series of piperazine sulfonamide-based 11β-HSD1 inhibitors is described. (R)-3,3,3-Trifluoro-2-(5-(((R)-4-(4-fluoro-2-(trifluoromethyl)phenyl)-2-methylpiperazin-1-yl)sulfonyl)thiophen-2-yl)-2-hydroxypropanamide 18a (HSD-621) was identified as a potent and selective 11β-HSD1 inhibitor and was ultimately selected as a clinical development candidate. HSD-621 has an attractive overall pharmaceutical profile and demonstrates good oral bioavailability in mouse, rat, and dog. When orally dosed in C57/BL6 diet-induced obesity (DIO) mice, HSD-621 was efficacious and showed a significant reduction in both fed and fasting glucose and insulin levels. Furthermore, HSD-621 was well tolerated in drug safety assessment studies.

11beta-Hydroxysteroid dehydrogenase type 1 inhibitors: novel agents for the treatment of metabolic syndrome and obesity-related disorders?

OBJECTIVE

Metabolic syndrome (MetS) and Cushing's syndrome share common features. It has been proposed that increased glucocorticoid activity at peripheral tissues may play a role in the pathogenesis of MetS and obesity-related disorders. It is well-known that intracellular cortisol concentrations are determined not only by plasma levels but also by the activity of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) which catalyzes the conversion of inactive cortisone to active cortisol, especially in the liver and adipose tissue. Another isoenzyme exists, the 11β-hydroxysteroid dehydrogenase type 2, which acts in the opposite direction inactivating cortisol to cortisone in the kidney. This review considers the significance of the 11β-HSD1 inhibition in the treatment of several features of MetS and provides current data about the development of 11β-HSD1 inhibitors, as new agents for this purpose.

MATERIALS/METHODS

Using PubMed, we searched for publications during the last 20years regarding the development of 11β-HSD1 inhibitors.

RESULTS

Emerging data from animal and human studies indicate an association of 11β-HSD1 over-expression with obesity and disorders in glucose and lipid metabolism. This has led to the hypothesis that selective inhibition of 11β-HSD1 could be used to treat MetS and diabetes. Indeed, natural products and older agents such as thiazolidinediones and fibrates seem to exert an inhibitory effect on 11β-HSD1, ameliorating the cardiometabolic profile. In view of this concept, novel compounds, such as adamantyltriazoles, arylsulfonamidothiazoles, anilinothiazolones, BVT2733, INCB-13739, MK-0916 and MK-0736, are currently under investigation and the preliminary findings from both experimental and human studies show a favourable effect on glucose and lipid metabolism, weight reduction and adipokine levels.

CONCLUSIONS

Many compounds inhibiting 11β-ΗSD1 are under development and preliminary data about their impact on glucose metabolism and obesity-related disorders are encouraging.

11β-Hydroxysteroid dehydrogenase type 1: relevance of its modulation in the pathophysiology of obesity, the metabolic syndrome and type 2 diabetes mellitus

Recent evidence strongly argues for a pathogenic role of glucocorticoids and 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) in obesity and the metabolic syndrome, a cluster of risk factors for atherosclerotic cardiovascular disease and type 2 diabetes mellitus (T2DM) that includes insulin resistance (IR), dyslipidaemia, hypertension and visceral obesity. This has been partially prompted not only by the striking clinical resemblances between the metabolic syndrome and Cushing's syndrome (a state characterized by hypercortisolism that associates with metabolic syndrome components) but also from monogenic rodent models for the metabolic syndrome (e.g. the leptin-deficient ob/ob mouse or the leptin-resistant Zucker rat) that display overall increased secretion of glucocorticoids. However, systemic circulating glucocorticoids are not elevated in obese patients and/or patients with metabolic syndrome. The study of the role of 11β-HSD system shed light on this conundrum, showing that local glucocorticoids are finely regulated in a tissue-specific manner at the pre-receptor level. The system comprises two microsomal enzymes that either activate cortisone to cortisol (11β-HSD1) or inactivate cortisol to cortisone (11β-HSD2). Transgenic rodent models, knockout (KO) for HSD11B1 or with HSD11B1 or HSD11B2 overexpression, specifically targeted to the liver or adipose tissue, have been developed and helped unravel the currently undisputable role of the enzymes in metabolic syndrome pathophysiology, in each of its isolated components and in their prevention. In the transgenic HSD11B1 overexpressing models, different features of the metabolic syndrome and obesity are replicated. HSD11B1 gene deficiency or HSD11B2 gene overexpression associates with improvements in the metabolic profile. In face of these demonstrations, research efforts are now being turned both into the inhibition of 11β-HSD1 as a possible pharmacological target and into the role of dietary habits on the establishment or the prevention of the metabolic syndrome, obesity and T2DM through 11β-HSD1 modulation. We intend to review and discuss 11β-HSD1 and obesity, the metabolic syndrome and T2DM and to highlight the potential of its inhibition for therapeutic or prophylactic approaches in those metabolic diseases.

In utero and neonate exposure to nonylphenol develops hyperadrenalism and metabolic syndrome later in life. I. First generation rats (F(1))

Nonylphenol (NP) is an endocrine disruptor (ENDR). It is a chemical associated with the production and degradation of nonylphenol ethoxylates (NPE). NPE is widely used as nonionic surfactants. Previously, we observed that NP increased the production of corticosterone and aldosterone from zona fasciculata-reticularis, and zona glomerulosa cells, respectively. By the "fetal origins adult diseases" (Barker hypothesis), we examined the possible impact of NP exposure during developmental (in utero and neonatal) period with focus on disturbed adrenal function and related hyperadrenal syndrome, i.e. Cushings syndrome/metabolic syndrome. In this study, female rats drink NP water during pregnancy and lactation conferred F(1) generation: (1) increase the corticosterone, aldosterone concentration in plasma; (2) increase 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) activity in liver and adipose tissue; (3) increase aldosterone synthase activity in adrenal for adult offspring. Furthermore, it can increase body weight, adrenocorticotropin (ACTH) concentration in plasma, 11β-HSD1 protein expression in liver, steroidogenic acute regulatory (StAR) protein expression and 11β-hydroxylase activity in adrenal for male adult offspring. In summary, NP exposure during developmental period bestowed F(1) generation with hyperadrenalism and its consequence of metabolic syndrome.