Synthesis of sterically encumbered 11β-aminoprogesterone derivatives and evaluation as 11β-hydroxysteroid dehydrogenase inhibitors and mineralocorticoid receptor antagonists

11β-Hydroxyprogesterone is a well-known nonselective inhibitor of 11β-hydroxysteroid dehydrogenase (11βHSD) types 1 and 2. It also activates the mineralocorticoid receptor (MR). Modulation of corticosteroid action by inhibition of 11βHSDs or blocking MR is currently under consideration for treatment of electrolyte disturbances, metabolic diseases and chronic inflammatory disorders. We established conditions to synthesize sterically demanding 11β-aminoprogesterone, which following subsequent nucleophilic or reductive amination, allowed extension of the amino group to prepare amino acid derivatives. Biological testing revealed that some of the 11β-aminoprogesterone derivatives selectively inhibit 11βHSD2. Moreover, two compounds that did not significantly inhibit 11βHSDs had antagonist properties on MR. The 11β-aminoprogesterone derivatives form a basis for the further development of improved modulators of corticosteroid action.     

Discovery of cyclicsulfonamide derivatives as 11β-hydroxysteroid dehydrogenase 1 inhibitors

A new series of cyclic sulfonamide derivatives was synthesized and evaluated for their ability to inhibit 11β-HSD1. Cyclic sulfonamides with phenylacetyl substituents at the 2-position showed nanomolar inhibitory activities. Among them, compound 4e exhibited a good in vitro inhibitory activity and selectivity toward human 11β-HSD2.     

Discovery and optimization of adamantyl carbamate inhibitors of 11β-HSD1

Synthesis of 2-adamantyl carbamate derivatives of piperidines and pyrrolidines led to the discovery of 9a with an IC₅₀ of 15.2 nM against human 11β-HSD1 in adipocytes. Optimization for increased adipocyte potency, metabolic stability and selectivity afforded 11k and 11l, both of which were >25% orally bioavailable in rat.     

A novel derivatives of thiazol-4(5H)-one and their activity in the inhibition of 11β-hydroxysteroid dehydrogenase type 1

11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) is an enzyme that catalyzes the conversion of inactive cortisone into physiologically active cortisol. Inhibiting the activity of this enzyme plays a key role in the treatment of Cushing's syndrome, metabolic syndrome and type 2 diabetes. Therefore, new compounds that are selective inhibitors of this enzyme are constantly being looked for.In this work we present the synthesis of 2-(allylamino)thiazol-4(5H)-one derivatives by the reaction of N-allylthiourea with appropriate α-bromoesters. In the case of using of aliphatic α-bromoesters and α-bromo-β-phenylesters, the reactions were carried out in a basic medium (sodium ethoxide) and the products were isolated with a yield of up to 68%. Derivatives containing spiro systems in which carbon C-5 of the thiazole ring is the linker atom were obtained in the presence of N,N-diisopropylethylamine.Some of the obtained compounds, at a concentration of 10 μM have activity in the inhibition of 11β-HSD1 up to 71%. IC₅₀ value for the most active compound: 2-(allylamino)-1-thia-3-azaspiro[4.5]dec-2-en-4-one is 2.5 µM. With a high degree of 11β-HSD1 inhibition and a relatively large difference in the inhibition of 11β-HSD1 and 11β-HSD2 activity, this compound appears to be promising and should be subjected to further testing.     

Synthesis and characterization of IMPY derivatives that regulate metal-induced amyloid-β aggregation

Metal ions associated with amyloid-β (Aβ) species have been suggested to be involved in neurodegeneration leading to the progression of Alzheimer's disease (AD). The role of metal-involved Aβ species in AD neuropathogenesis, however, is not fully elucidated. In order to advance this understanding and contribute to the therapeutic development for AD, the rational structure-based design of small molecules that specifically target metal ions surrounded by Aβ species has recently received increased attention. To date, only a few compounds have been fashioned for this purpose. Herein, we report the design strategy, synthesis, characterization, and reactivity of new bifunctional IMPY derivatives K1 and K2. Using UV-vis and high-resolution two-dimensional (2D) NMR spectroscopy, the bifunctionality of K1 and K2 (metal chelation and Aβ interaction) was confirmed. These bifunctional IMPY derivatives showed preferential reactivity toward metal-induced Aβ aggregation over metal-free conditions in both in vitro inhibition and disaggregation experiments. Taken together, this study provides another example of a bifunctional small molecule framework that can target metal ions associated with Aβ species.     

Synthesis, α-glucosidase inhibition and molecular docking study of coumarin based derivatives

We have synthesized seventeen Coumarin based derivatives (1–17), characterized by ¹HNMR, ¹³CNMR and EI-MS and evaluated for α-glucosidase inhibitory potential. Among the series, all derivatives exhibited outstanding α-glucosidase inhibition with IC₅₀ values ranging between 1.10 ± 0.01 and 36.46 ± 0.70 μM when compared with the standard inhibitor acarbose having IC₅₀ value 39.45 ± 0.10 μM. The most potent derivative among the series is derivative 3 having IC₅₀ value 1.10 ± 0.01 μM, which are many folds better than the standard acarbose. The structure activity relationship (SAR) was mainly based upon by bring about difference of substituent’s on phenyl part. Molecular docking studies were carried out to understand the binding interaction of the most active compounds.     

Synthesis and evaluation of piperidine urea derivatives as efficacious 11β-hydroxysteroid dehydrogenase type 1 inhibitors in diabetic ob/ob mice

11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) has attracted considerable attention as a potential target for the treatment of diabetes and metabolic syndrome. Herein we report the design, synthesis and efficacy evaluation of novel amide and urea 11β-HSD1 inhibitors. Structure-activity relationship studies led to the identification of 10c, which was efficacious in a diabetic ob/ob mouse model and reduced fasting and non-fasting blood glucose levels after ip dosing.     

Synthesis and antibacterial activity of 4″,11-di-O-arylalkylcarbamoyl azithromycin derivatives

A series of new 4″,11-di-O-arylalkylcarbamoyl azithromycin derivatives were designed, synthesized and evaluated for their in vitro antibacterial activities. Some derivatives exhibited greatly improved activity against erythromycin-resistant bacteria. Among them, compounds 5f and 5k were found to have potent activity against erythromycin-resistant Streptococcus pneumoniae whose resistance was encoded by the erm or mef gene.     

Synthesis of novel 3-amino and 29-hydroxamic acid derivatives of glycyrrhetinic acid as selective 11β-hydroxysteroid dehydrogenase 2 inhibitors

Glycyrrhetinic acid, the metabolite of the natural product glycyrrhizin, is a well known nonselective inhibitor of 11β-hydroxysteroid dehydrogenase (11β-HSD) type 1 and type 2. Whereas inhibition of 11β-HSD1 is currently under consideration for treatment of metabolic diseases, such as obesity and diabetes, 11β-HSD2 inhibitors may find therapeutic applications in chronic inflammatory diseases and certain forms of cancer. So far, no selective 11β-HSD2 inhibitor has been developed and neither animal studies nor clinical trials have been reported based on 11β-HSD2 inhibition. Starting from the lead compound glycyrrhetinic acid, novel triterpene type derivatives were synthesized and analyzed for their biological activity against overexpressed human 11β-HSD1 and 11β-HSD2 in cell lysates. Several hydroxamic acid derivatives showed high selectivity for 11β-HSD2. The most potent and selective compound is active against human 11β-HSD2 in the low nanomolar range with a 350-fold selectivity over human 11β-HSD1.     

Effects of antisense-mediated inhibition of 11β-hydroxysteroid dehydrogenase type 1 on hepatic lipid metabolism

11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) converts inactive 11-keto derivatives to active glucocorticoids within tissues and may play a role in the metabolic syndrome (MS). We used an antisense oligonucleotide (ASO) to knock down 11β-HSD1 in livers of C57BL/6J mice consuming a Western-type diet (WTD). 11β-HSD1 ASO-treated mice consumed less food, so we compared them to ad libitum-fed mice and to food-matched mice receiving control ASO. Knockdown of 11β-HSD1 directly protected mice from WTD-induced steatosis and dyslipidemia by reducing synthesis and secretion of triglyceride (TG) and increasing hepatic fatty acid oxidation. These changes in hepatic and plasma lipids were not associated with reductions in genes involved in de novo lipogenesis. However, protein levels of both sterol regulatory element-binding protein (SREBP) 1 and fatty acid synthase were significantly reduced in mice treated with 11β-HSD1 ASO. There was no change in hepatic secretion of apolipoprotein (apo)B, indicating assembly and secretion of smaller apoB-containing lipoproteins by the liver in the 11β-HSD1-treated mice. Our results indicate that inhibition of 11β-HSD1 by ASO treatment of WTD-fed mice resulted in improved plasma and hepatic lipid levels, reduced lipogenesis by posttranslational regulation, and secretion of similar numbers of apoB-containing lipoproteins containing less TG per particle.     

The inhibition of human and rat 11β-hydroxysteroid dehydrogenase 2 by perfluoroalkylated substances

11β-Hydroxysteroid dehydrogenase 2 (11β-HSD2) regulates active glucocorticoid access to glucocorticoid and mineralocorticoid receptors by metabolizing it to an inactive form. Perfluoroalkylated substances (PFASs) are man-made polyfluorinated compounds that are widely used and persistent in the environment. We tested the inhibitory potencies of four PFASs including perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorohexanesulfonate (PFHxS) and perfluorobutane sulfonate (PFBS) on human and rat 11β-HSD2. PFOS was a potent inhibitor of both human (IC(50)=48 nM) and rat (IC(50)=293 nM) 11β-HSD2 activities. The potencies for the inhibition of human and rat 11β-HSD2 activities were PFOS>PFOA>PFHxS>PFBS. PFASs showed competitive inhibition of both human and rat 11β-HSD2 activities. This observation indicates that PFOS is a potent endocrine disruptor for glucocorticoid metabolism. Article from the Special issue on Targeted Inhibitors.     

Structure-dependent inhibition of human and rat 11β-hydroxysteroid dehydrogenase 2 activities by phthalates

Phthalates are diesters of phthalic acid and an alcohol moiety. Phthalates have been classified as endocrine disruptors and have a broad range of effects with unknown mechanisms. Some of the effects of phthalate are consistent with disruptions of normal glucocorticoid homeostasis, and in particular, with defective function of 11β-hydroxysteroid dehydrogenase 2 (11β-HSD2). In the present study, we tested 12 phthalate diesters and four monoesters for the inhibition of human and rat kidney 11β-HSD2. We examined the modes of inhibition and looked for a relationship between the potency for inhibition and the chemical structures. Of the phthalate diesters we tested, dipropyl phthalate (DPrP) and di-n-butyl phthalate (DBP) significantly inhibited both human and rat 11β-HSD2 activities. The IC₅₀s were 85.59 μM for DPrP and 13.69 μM for DBP when calculated for rat 11β-HSD2. As diesters, 8 of the phthalates did not affect 11β-HSD2 enzyme activity. Compared to the diesters that were inhibitory, the 8 non-inhibitory phthalates, had either fewer carbons, that is 1 or 2 carbons in the alcohol moiety, or more carbons, 5–10, as a branched or unbranched chain in the alcohol moeity. However, phthalates could be inhibitors with six carbons in the alcohol moiety if the carbons were cyclized, as in dicyclohexyl phthalate (DCHP), which inhibited rat 11β-HSD2 with an IC₅₀ of 32.64 μM. Thus, whether a phthalate is an inhibitor may reflect the size and shape of the compound. Although the diesters are the compounds used in manufacturing and present as environmental contaminants, it is the monoester metabolites that are detected in human serum and urine. We showed that mono (2-ethylhexyl) phthalate (MEHP) significantly inhibited human (IC₅₀ = 110.8 ± 10.9) and rat (121.8 ± 8.5 μM) 11β-HSD2 activity even though its parent compound, di(2-ethylhexyl) phthalate (DEHP) did not. MEHP was a competitive inhibitor of 11β-HSD2 enzymatic activity. We conclude that phthalates of a certain size act as competitive inhibitors.     

The determination by microdensitometry of the initial maximum velocity rate of rat ovarian 3β hydroxysteroid dehydrogenase activity

Summary The determination of the initial maximum velocity rate of 3 hydroxysteroid dehydrogenase activity (3 HSD) of the newest generation of corpora lutea of the adult dioestrous rat ovary is described. Under conditions where the substrate and co-factor concentrations are not rate limiting (4×10^–4 M epiandrosterone; 3×10^–3 M NAD⁺ respectively) the initial maximum reaction rate was maintained for approximately 6 min. NADH production during this period was 4.9±0.2 moles/min/cm³ of corpora lutea.     

Synthesis and optimization of arylsulfonylpiperazines as a novel class of inhibitors of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1)

The synthesis and SAR of a series of arylsulfonylpiperazine inhibitors of 11β-HSD1 are described. Optimization rapidly led to potent, selective, and orally bioavailable inhibitors demonstrating efficacy in a cynomolgus monkey ex vivo enzyme inhibition model.     

Synthesis,anti-diabetic evaluation and molecular docking studies of 4-(1-aryl-1H-1, 2, 3-triazol-4-yl)-1,4-dihydropyridine derivatives as novel 11-β hydroxysteroid dehydrogenase-1 (11β-HSD1) inhibitors

11-Beta-Hydroxysteroid dehydrogenase-1(11β-HSD1) inhibitors are one of the emerging classes of molecules to fight against diabetic complications. A novel series of 4-(1-substituted-1H-1,2,3-triazol-4-yl)-1,4-dihydropyridine derivatives were synthesized and evaluated for their anti-diabetic activity. Two compounds showed anti-diabetic activity very effectively. To clarify the mechanism of action of these compounds, the most potent compounds (5g and 5h) of the synthesized analogs were further studied by testing its 11-Beta Hydroxysteroid dehydrogenase-1 inhibitory activity through in vitro enzymatic experiments. The results showed that the 11β-HSD1 inhibitory activity of compounds 5g and 5h was stable and efficient. Molecular docking studies revealed compounds 5g (−9.758) and 5h (−8.495) to have a stable binding patterns to the human 11-Beta-Hydroxysteroid dehydrogenase-1.     

Synthesis of thiobarbituric acid derivatives: In vitro α-glucosidase inhibition and molecular docking studies

Synthesis, structure, and evaluation of in vitro α-glucosidase enzyme inhibition of a new class of diethylammonium salts of aryl substituted thiobarbituric acid is described. This protocol is straight, environmentally benign and efficient, involving Aldol-Michael addition reaction in one pot fashion. The 3D chemical structures of the synthesized compounds were assigned based on spectroscopic methods and X-ray single crystal diffraction analyses. All synthesized compounds 3a-3n were evaluated for their in vitro α-glucosidase enzyme inhibitory activity, whereas acarbose was used as the standard drug (IC₅₀ = 840 ± 1.73 µM). All tested compounds were found to possess varying degree of α-glucosidase enzyme inhibition activity with (IC₅₀ = 19.46 ± 1.84–415.8 ± 4.0 µM). Compound 3i (IC₅₀ = 19.4 ± 1.84 µM) exhibited the highest activity. To the best of knowledge this is the first report of the in vitro α-glucosidase enzyme inhibition by the diethylamonium salts of aryl substituted thiobarbituric acid. Furthermore, molecular docking studies of selected compounds were also performed to see interactions between active compounds and binding sites.     

Synthesis and optimization of novel 4,4-disubstituted cyclohexylbenzamide derivatives as potent 11β-HSD1 inhibitors

The synthesis and SAR of a series of 4,4-disubstituted cyclohexylbenzamide inhibitors of 11β-HSD1 are described. Optimization rapidly led to potent, highly selective, and orally bioavailable inhibitors demonstrating efficacy in both rat and non-human primate ex vivo pharmacodynamic models.     

Synthesis and biological analysis of benzazol-2-yl piperazine sulfonamides as 11β-hydroxysteroid dehydrogenase 1 inhibitors

In the last decade the inhibition of the enzyme 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) emerged as a promising new strategy to treat diabetes and several metabolic syndrome phenotypes. Using a molecular modeling approach and classical bioisosteric studies, we discovered a new class of 11β-HSD1 inhibitors bearing an arylsulfonylpiperazine scaffold. Optimization of the initial lead resulted in compound 11 that selectively inhibits 11β-HSD1 (IC₅₀ = 0.7 μM).