Discovery of novel inhibitors of 11beta-hydroxysteroid dehydrogenase type 1 by docking and pharmacophore modeling

Two new sesquiterpenes from cultures of the fungus Irpex lacteus

Two new tremulane-type sesquiterpenes, irlactin L (1) and irlactin M (2) were isolated from cultures of the fungus Irpex lacteus, together with one known compound, 6-hydroxy-2,6-dimethyloct-7-enoic acid (3). Their structures were elucidated by spectroscopic data analysis. Compounds 1-2 were tested for their cytotoxicities against five human cancer cell lines and for their inhibitory activities against isozymes of 11β-hydroxysteroid dehydrogenases (11β-HSD).[Formula: see text].

Enteric Microbiota⁻Gut⁻Brain Axis from the Perspective of Nuclear Receptors

Nuclear receptors (NRs) play a key role in regulating virtually all body functions, thus maintaining a healthy operating body with all its complex systems. Recently, gut microbiota emerged as major factor contributing to the health of the whole organism. Enteric bacteria have multiple ways to influence their host and several of them involve communication with the brain. Mounting evidence of cooperation between gut flora and NRs is already available. However, the full potential of the microbiota interconnection with NRs remains to be uncovered. Herewith, we present the current state of knowledge on the multifaceted roles of NRs in the enteric microbiota–gut–brain axis.

A new tremulane sesquiterpenoid from the fungus Irpex lacteus

A new tremulane sesquiterpenoid, named irlactam A (1), was isolated from cultures of the fungus Irpex lacteus. The new structure was elucidated by spectroscopic data analysis. The compound was tested for its cytotoxicities on HL-60, SMMC-7721, A-549, MCF-7, and SW480 cells and for its inhibitory activity against isozymes of 11 β-hydroxysteroid dehydrogenases (11 β-HSD).

Synthesis of selective 11β-HSD1 inhibitors based on dammarane scaffold

Inspired by natural 11β-HSD1 inhibitors hupehenols A - E, a ring-focused strategy was applied for the synthesis of 35 structurally diverse dammarane-type derivatives. These derivatives were effectively prepared from protopanaxadiol based on the modification of rings A and D. Among these compounds, ten were identified as selective 11β-HSD1 inhibitors (IC50 range: 101-1047 nM, SI range: 8-169) which exhibited inhibitory activities against human or mouse 11β-HSD1. Otherwise, we found 23a could selectively inhibit both human and mouse 11β-HSD1 with IC50 value of 994 and 213 nM (SI > 10 and > 47), respectively. Additionally, the molecular modelling results of 23a docking into the human and mouse 11β-HSD1 were in good agreement with the results from the enzyme inhibitory experiment. Moreover, valuable structural-activity relationship (SAR) information of dammarane-type 11β-HSD1 inhibitor was summarized.

Virtual screening applications in short-chain dehydrogenase/reductase research

Several members of the short-chain dehydrogenase/reductase (SDR) enzyme family play fundamental roles in adrenal and gonadal steroidogenesis as well as in the metabolism of steroids, oxysterols, bile acids, and retinoids in peripheral tissues, thereby controlling the local activation of their cognate receptors. Some of these SDRs are considered as promising therapeutic targets, for example to treat estrogen-/androgen-dependent and corticosteroid-related diseases, whereas others are considered as anti-targets as their inhibition may lead to disturbances of endocrine functions, thereby contributing to the development and progression of diseases. Nevertheless, the physiological functions of about half of all SDR members are still unknown. In this respect, in silico tools are highly valuable in drug discovery for lead molecule identification, in toxicology screenings to facilitate the identification of hazardous chemicals, and in fundamental research for substrate identification and enzyme characterization. Regarding SDRs, computational methods have been employed for a variety of applications including drug discovery, enzyme characterization and substrate identification, as well as identification of potential endocrine disrupting chemicals (EDC). This review provides an overview of the efforts undertaken in the field of virtual screening supported identification of bioactive molecules in SDR research. In addition, it presents an outlook and addresses the opportunities and limitations of computational modeling and in vitro validation methods.

16-nor Limonoids from Harrisonia perforata as promising selective 11β-HSD1 inhibitors

Two new 16-nor limonoids, harperspinoids A and B (1 and 2), with a unique 7/5/5/6/5 ring system, have been isolated from the plant Harrisonia perforate together with a known one, Harperforin G (3). Their structures were elucidated by NMR spectroscopy, X-ray diffraction analysis and computational modelling. Compound 1 exists as polymorphic crystals. Conformations of 1 in solution were further discussed based on the computational results. These compounds exhibited notable inhibitory activity against the 11β-HSD1 enzyme. Compound 3 had potencies for the inhibition of human 11β-HSD1 with high selectivity against 11β-HSD2 (IC₅₀ 0.58 μM, SI > 174). Molecular docking and quantitative structure-activity relationship studies revealed a mixed regulatory mechanism.

Molecular Modeling Studies of 11β-Hydroxysteroid Dehydrogenase Type 1 Inhibitors through Receptor-Based 3D-QSAR and Molecular Dynamics Simulations

11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) is a potential target for the treatment of numerous human disorders, such as diabetes, obesity, and metabolic syndrome. In this work, molecular modeling studies combining molecular docking, 3D-QSAR, MESP, MD simulations and free energy calculations were performed on pyridine amides and 1,2,4-triazolopyridines as 11β-HSD1 inhibitors to explore structure-activity relationships and structural requirement for the inhibitory activity. 3D-QSAR models, including CoMFA and CoMSIA, were developed from the conformations obtained by docking strategy. The derived pharmacophoric features were further supported by MESP and Mulliken charge analyses using density functional theory. In addition, MD simulations and free energy calculations were employed to determine the detailed binding process and to compare the binding modes of inhibitors with different bioactivities. The binding free energies calculated by MM/PBSA showed a good correlation with the experimental biological activities. Free energy analyses and per-residue energy decomposition indicated the van der Waals interaction would be the major driving force for the interactions between an inhibitor and 11β-HSD1. These unified results may provide that hydrogen bond interactions with Ser170 and Tyr183 are favorable for enhancing activity. Thr124, Ser170, Tyr177, Tyr183, Val227, and Val231 are the key amino acid residues in the binding pocket. The obtained results are expected to be valuable for the rational design of novel potent 11β-HSD1 inhibitors.

Synthesis of hupehenols A, B, and E from protopanaxadiol

A unified semisynthesis approach from protopanaxadiol to hupehenols A, B, and E was described. The synthesis provided the primary SAR and the possibility of further medicinal development of hupehenols.

Pharmacophore Models and Pharmacophore-Based Virtual Screening: Concepts and Applications Exemplified on Hydroxysteroid Dehydrogenases

Computational methods are well-established tools in the drug discovery process and can be employed for a variety of tasks. Common applications include lead identification and scaffold hopping, as well as lead optimization by structure-activity relationship analysis and selectivity profiling. In addition, compound-target interactions associated with potentially harmful effects can be identified and investigated. This review focuses on pharmacophore-based virtual screening campaigns specifically addressing the target class of hydroxysteroid dehydrogenases. Many members of this enzyme family are associated with specific pathological conditions, and pharmacological modulation of their activity may represent promising therapeutic strategies. On the other hand, unintended interference with their biological functions, e.g., upon inhibition by xenobiotics, can disrupt steroid hormone-mediated effects, thereby contributing to the development and progression of major diseases. Besides a general introduction to pharmacophore modeling and pharmacophore-based virtual screening, exemplary case studies from the field of short-chain dehydrogenase/reductase (SDR) research are presented. These success stories highlight the suitability of pharmacophore modeling for the various application fields and suggest its application also in futures studies.

Two new sesquiterpenoids from cultures of the basidiomycete Tremella foliacea

Two new sesquiterpenoids, trefoliol B (1) and trefoliol C (2), together with known echinocidin A (3), were isolated from cultures of the basidiomycetes Tremella foliacea. The new structures were elucidated on the basis of extensive spectroscopic methods. At the same time, trefoliol B (1) and echinocidin A (3) were tested for their cytotoxicities against five human cancer cell lines and for their inhibitory activities against isozymes of 11β-hydroxysteroid dehydrogenases (11β-HSD). No compound showed significant activity (IC50 > 40 μM). Compound 1 showed moderate inhibitory activities against 11β-HSD1 (human IC50 = 13.1 μM; mouse IC50 = 91.8 μM).

Hupehenols A-E, selective 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) inhibitors from Viburnum hupehense

Five selective 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) competitive inhibitors, hupehenols A-E (1-5), were isolated from Viburnum hupehense. The structure elucidation indicated that compounds 1-5 are new 20,21,22,23,24,25,26,27-octanordammarane triterpenoids. Their structures were established on the basis of NMR spectroscopic and mass spectrometric analysis. Hupehenols A-E (1-5) showed inhibition against human 11β-HSD1, with hupehenols B (2) and E (5) having IC50 values of 15.3 and 34.0 nM, respectively. Moreover, hupehenols C (3) and D (4) are highly selective inhibitors of human 11β-HSD1 when compared to murine 11β-HSD1.

Five New Guanacastane-Type Diterpenes from Cultures of the Fungus Psathyrella candolleana

Five new guanacastane-type diterpenes, named guanacastepenes P-T (1-5), were isolated from cultures of the fungus Psathyrella candolleana. Their structures were elucidated on the basis of extensive spectroscopic methods. All of the compounds were tested for their 11β-hydroxysteroid dehydrogenase (11β-HSD1) inhibitory activity. Compound 3 exhibited inhibitory activity against both human and mouse isozymes of 11β-HSD1 with IC50 values of 6.2 and 13.9 μM, respectively.

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.

The biology of the glucocorticoid receptor: new signaling mechanisms in health and disease

Glucocorticoids are primary stress hormones necessary for life that regulate numerous physiologic processes in an effort to maintain homeostasis. Synthetic derivatives of these hormones have been mainstays in the clinic for treating inflammatory diseases, autoimmune disorders, and hematologic cancers. The physiologic and pharmacologic actions of glucocorticoids are mediated by the glucocorticoid receptor (GR), a member of the nuclear receptor superfamily of ligand-dependent transcription factors. Ligand-occupied GR induces or represses the transcription of thousands of genes through direct binding to DNA response elements, physically associating with other transcription factors, or both. The traditional view that glucocorticoids act through a single GR protein has changed dramatically with the discovery of a large cohort of receptor isoforms with unique expression, gene-regulatory, and functional profiles. These GR subtypes are derived from a single gene by means of alternative splicing and alternative translation initiation mechanisms. Posttranslational modification of these GR isoforms further expands the diversity of glucocorticoid responses. Here we discuss the origin and molecular properties of the GR isoforms and their contribution to the specificity and sensitivity of glucocorticoid signaling in healthy and diseased tissues.

A new triterpenoid from Teucrium viscidum

A new ursane-type triterpenoid, 3β-hydroxy-urs-30-p-Z-hydroxycinnamoyloxy-12-en-28-oic-acid (1), together with three known triterpenoids, 3β-hydroxy-urs-30-p-E-hydroxycinnamoyloxy-12-en-28-oic-acid (2), 2α,3β,19α-trihydroxy-urs-12-en-28-oic-acid (3), and ursolic acid (4), four known lignans, pinoresinol (5), 9α-hydroxypinoresinol (6), (+)-medioresinol (7), and (+)-kobusin (8), and two steroids, β-sitosterol (9), and daucosterol (10), were isolated from the whole parts of Teucrium viscidum. Their structures were established by a combination of spectroscopic data analysis, besides comparison with literature data. Compounds 1–4 were evaluated for their inhibitory activities against 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1).

Inhibition of 11b-HSD1 by tetracyclic triterpenoids from Euphorbia kansui

The roots of Euphorbia kansui are considered an important traditional folk medicine. In this study the ethanol extracts of E. kansui were investigated. A new tetracyclic triterpenoid, euphane-3β,20-dihydroxy-24-ene, in addition to five known triterpenoids with euphane skeletons were isolated. Their structures were elucidated on the basis of physical and spectral techniques (1D-, 2D-NMR and MS, respectively). Furthermore, these compounds 1–6 exhibited strong inhibitory activity against human 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), with IC₅₀ values of 34.86 nM, 1.115 μM, 16.08 nM, 2.815 nM, 26.47 nM, 15.99 nM, and 41.86 nM, respectively. The docking results show that the ring part of compounds can insert into the hydrophobic core of h11β-HSD1 and the alkane chain orientates toward the outside. The results presented herein provide a scientific explanation for the usage of the E. kansui in clinical treatment of diabetes.

Five new polyketides from the basidiomycete Craterellus odoratus

Five new polyketides, craterellones A–E (1–5), were isolated from cultures of basidiomycete Craterellus odoratus, together with five known compounds (6–10). Structures of 1–5 were elucidated on the basis of extensive spectroscopic analysis. All compounds were evaluated for their inhibitory activities against one isozyme of 11β-hydroxysteroid dehydrogenase (11β-HSD1) and cytotoxic activities on five tumor cell lines. Compound 10 exhibited significant cytotoxicity against HL-60, SMMC-7721, A-549, MCF-7, and SW-480, with IC50 values of 0.50, 0.69, 0.64, 1.10, 0.54 µM, respectively.

Analysis of structure-based virtual screening studies and characterization of identified active compounds

Structure-based virtual screening makes explicit or implicit use of 3D target structure information to detect novel active compounds. Results of nearly 300 currently available original applications have been analyzed to characterize the state-of-the-art in this field. Compound selection from docking calculations is much influenced by subjective criteria. Although submicromolar compounds are identified, the majority of docking hits are only weakly potent. However, only a small percentage of docking hits can be reproduced by ligand-based methods. When docking calculations identify potent hits, they often originate from specialized compound sources (e.g., pharmaceutical compound decks or target-focused libraries) and also display a notable bias towards kinase targets. Structure-based virtual screening is the dominant approach to computational hit identification. Docking calculations frequently identify active compounds. Limited accuracy of compound scoring and ranking currently presents a major caveat of the approach that is often compensated for by chemical intuition and knowledge.

Cycloartane and friedelane triterpenoids from the leaves of Caloncoba glauca and their evaluation for inhibition of 11β-hydroxysteroid dehydrogenases

Five new triterpenoids, caloncobic acids A and B (1 and 2), caloncobalactones A and B (3 and 4), and glaucalactone (5), along with the known compounds 3β,21β-dihydroxy-30-nor-(D:A)-friedo-olean-20(29)-en-27-oic acid (6) and acetyltrichadenic acid B (7), were isolated from the leaves of Caloncoba glauca. The structures of 1-5 were elucidated using spectroscopic methods. Compounds 1-7 were evaluated for their inhibitory activities against two isozymes of 11β-hydroxysteroid dehydrogenase (11β-HSD1 and 11β-HSD2). Compounds 1 and 2 exhibited strong inhibitory activities against mouse (EC(50) 132 and 13 nM) and human (EC(50) 105 and 72 nM) 11β-HSD1.

Identification of important chemical features of 11β-hydroxysteroid dehydrogenase type1 inhibitors: application of ligand based virtual screening and density functional theory

11β-Hydroxysteroid dehydrogenase type1 (11βHSD1) regulates the conversion from inactive cortisone to active cortisol. Increased cortisol results in diabetes, hence quelling the activity of 11βHSD1 has been thought of as an effective approach for the treatment of diabetes. Quantitative hypotheses were developed and validated to identify the critical chemical features with reliable geometric constraints that contribute to the inhibition of 11βHSD1 function. The best hypothesis, Hypo1, which contains one-HBA; one-Hy-Ali, and two-RA features, was validated using Fischer’s randomization method, a test and a decoy set. The well validated, Hypo1, was used as 3D query to perform a virtual screening of three different chemical databases. Compounds selected by Hypo1 in the virtual screening were filtered by applying Lipinski’s rule of five, ADMET, and molecular docking. Finally, five hit compounds were selected as virtual novel hit molecules for 11βHSD1 based on their electronic properties calculated by Density functional theory.

Four new compounds from the basidiomycete Craterellus odoratus

Four new compounds, craterellin D (1), 5-hydroxymethyl-2-hydroxy-4-methoxy-phenylethanone (2), 5-carboxyl-2-[2-(1,2-dihydroxyisopropyl)]-benzofuran (3), and 6α-hydroxy-3-methoxy-4α-methyl-2-cyclohexen-1-one (4), were isolated from cultures of the basidiomycete Craterellus odoratus, together with three known compounds craterellins A-C (5-7). Structures of 1-4 were elucidated on the basis of extensive spectroscopic analysis. Selected compounds were evaluated for their inhibitory activities against one isozyme of 11β-hydroxysteroid dehydrogenase (11β-HSD1) and cytotoxic activities on five tumor cell lines. Compound 2 was found to exhibit inhibitory activity against human 11β-HSD1 with an IC₅₀ value of 16.4 μg/ml.

Cyclopeptide Alkaloids from Ziziphus apetala

Six novel Ia₃-type cyclopeptide alkaloids (1-6) were isolated from stems of Ziziphus apetala. Compound 5 and the known compounds mauritine A (7) and mauritine F (8) were isolated from the roots. Their structures were determined by spectroscopic analyses and chemical methods. The total alkaloids from the roots and the isolated cyclopeptide alkaloids were tested for antidepressant behavior on mice, cytotoxicity, and 11β-hydroxysteroid dehydrogenase (11β-HSD) inhibition in vitro. Only mauritine A (7) showed inhibitory activity on 11β-HSD1, with IC₅₀ values of 52.0 (human) and 31.2 μg/mL (mouse).

Chemical constituents and their bioactivities of "Tongling White Ginger" (Zingiber officinale)

Gingerols and their corresponding dehydration products shogaols were considered as the active principles of ginger, the rhizome of the plant Zingiber officinale, for its antioxidant, anti-inflammatory, and antitumor activities. Ginger (Z. officinale) has been cultivated for thousands of years as a spice and for medicinal purposes in China. Tongling (Anhui province, China) has traditionally been regarded as an ideal cultivation place. "Tongling White Ginger" enjoys a reputation for being one of the top gingers in China for its thin white peel, tender flesh, rich juice, and flavor. In this study, we have isolated and identified two novel gingerdione dimers, bisgingerdiones A (1) and B (2); two new gingerol derivatives, (5R)-5-acetoxy-1,7-bis(4-hydroxy-3-methoxyphenyl)heptan-3-one (3) and methyl (Z)-neral acetal-[6]-gingerdiol (4); and 38 known compounds (5-42) from rhizomes of Zingiber officinale collected from Tongling, China. Their structures were elucidated by means of spectroscopic methods. Compounds 1-4 showed weak cytotoxic and anti-HIV-1 activities. Compounds 6, 8, and 26 showed inhibitory activities against human and mouse 11β-HSD1 (11β-hydroxysteroid dehydrogenases) with IC(50) values between 1.09 and 1.30 μM.

Rare merosesquiterpenoids from basidiomycete Craterellus odoratus and their inhibition of 11beta-hydroxysteroid dehydrogenases

Rare merosesquiterpenoids, craterellins A-C (1-3), were isolated from cultures of basidiomycete Craterellus odoratus together with the previously known massarinolin C (4). Structures of 1-3 were elucidated on the basis of extensive spectroscopic analysis. Compounds 1-3 possess a rare, epoxymethylenecyclohexanetriol-bicyclofarnesane sesquiterpene hybrid skeleton. Compounds 1-4 were evaluated for their inhibitory activities against two isozymes of 11beta-hydroxysteroid dehydrogenases (11beta-HSD1 and 11beta-HSD2).

Tissue-specific glucocorticoid action: a family affair

Glucocorticoids exert a wide variety of physiological and pathological responses, most of which are mediated by the ubiquitously expressed glucocorticoid receptor (GR). The glucocorticoid response varies among individuals, as well as within tissues from the same individual, and this phenomenon can be partially explained through understanding the process of generating bioavailable ligand and the molecular heterogeneity of GR. This review focuses on the recent advances in our understanding of prereceptor ligand metabolism, GR subtypes and GR polymorphisms. Furthermore, we evaluate the impact of tissue- and individual-specific diversity in the glucocorticoid pathway on human health and disease.