1
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Chojnacka W, Teng J, Kim JJ, Jensen AA, Hibbs RE. Structural insights into GABA A receptor potentiation by Quaalude. Nat Commun 2024; 15:5244. [PMID: 38898000 PMCID: PMC11187190 DOI: 10.1038/s41467-024-49471-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 05/31/2024] [Indexed: 06/21/2024] Open
Abstract
Methaqualone, a quinazolinone marketed commercially as Quaalude, is a central nervous system depressant that was used clinically as a sedative-hypnotic, then became a notorious recreational drug in the 1960s-80s. Due to its high abuse potential, medical use of methaqualone was eventually prohibited, yet it persists as a globally abused substance. Methaqualone principally targets GABAA receptors, which are the major inhibitory neurotransmitter-gated ion channels in the brain. The restricted status and limited accessibility of methaqualone have contributed to its pharmacology being understudied. Here, we use cryo-EM to localize the GABAA receptor binding sites of methaqualone and its more potent derivative, PPTQ, to the same intersubunit transmembrane sites targeted by the general anesthetics propofol and etomidate. Both methaqualone and PPTQ insert more deeply into subunit interfaces than the previously-characterized modulators. Binding of quinazolinones to this site results in widening of the extracellular half of the ion-conducting pore, following a trend among positive allosteric modulators in destabilizing the hydrophobic activation gate in the pore as a mechanism for receptor potentiation. These insights shed light on the underexplored pharmacology of quinazolinones and further elucidate the molecular mechanisms of allosteric GABAA receptor modulation through transmembrane binding sites.
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Affiliation(s)
- Weronika Chojnacka
- Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, CA, USA
- Department of Neurobiology, University of California San Diego, La Jolla, CA, USA
| | - Jinfeng Teng
- Department of Neurobiology, University of California San Diego, La Jolla, CA, USA
| | - Jeong Joo Kim
- Protein Structure and Function, Loxo@Lilly, Louisville, CO, USA
| | - Anders A Jensen
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Ryan E Hibbs
- Department of Neurobiology, University of California San Diego, La Jolla, CA, USA.
- Department of Pharmacology, University of California San Diego, La Jolla, CA, USA.
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2
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Pinder NE, Ligocki IY, Horton BM, Hoover JE. Valerenic acid reduces anxiety-like behavior in young adult, female (C57BL/6J) mice. Behav Brain Res 2024; 457:114717. [PMID: 37852540 DOI: 10.1016/j.bbr.2023.114717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 10/05/2023] [Accepted: 10/14/2023] [Indexed: 10/20/2023]
Abstract
Extracts from the plant Valeriana officinalis are marketed as an herbal remedy to treat anxiety and insomnia. Valerenic acid (VA) is a major chemical component of Valeriana extracts. To date, there is relatively little information about how VA affects behavior. The purpose of these experiments was to (1) test whether administration of VA induces measurable changes in anxiety-like, depression-like, or locomotor behaviors; (2) determine whether the effects of VA on behavior are dose-dependent; and (3) compare the effects of VA on behavior to those of diazepam, a commonly prescribed treatment for anxiety. Young adult, female mice (C57BL/6J; 3-4 months old; 12 mice/group) were given one of three dosages of VA (3 mg/kg, 6 mg/kg, or 12 mg/kg), diazepam (1 mg/kg), or a vehicle control solution (20% ethanol v/v) by intraperitoneal injection. Thirty minutes after injection, each mouse was tested in the elevated plus maze (EPM), open field test (OFT), and tail suspension test (TST), in that order. All tests were video recorded and analyzed for relevant behavioral parameters. The results demonstrated that VA treatment effectively reduced multiple anxiety-related behaviors measured in the EPM. In fact, at a dose of 12 mg/kg, the anxiolytic effect of VA was just as robust as that of diazepam. Furthermore, the effects of VA on behavior were specifically anxiolytic, as VA did not induce changes in locomotor activity in the OFT, or depression-related behavior as measured in the TST. Our results provide strong support for VA as a putative anxiolytic drug.
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Affiliation(s)
- Natalie E Pinder
- Department of Biology, Millersville University, P.O. Box 1002, Millersville, PA 17551, USA
| | - Isaac Y Ligocki
- Department of Biology, Millersville University, P.O. Box 1002, Millersville, PA 17551, USA
| | - Brent M Horton
- Department of Biology, Millersville University, P.O. Box 1002, Millersville, PA 17551, USA
| | - John E Hoover
- Department of Biology, Millersville University, P.O. Box 1002, Millersville, PA 17551, USA.
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3
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Song Y, Hu Y, Li J, Wang L, Jing W, Zhang L, Dai Y, Jia S, Meng X, Zhang H. Site-Directed Mutation of Salicylate Decarboxylase Gene and Mechanism of Ginkgo Acid Decarboxylation. Protein J 2023; 42:1-13. [PMID: 36527585 DOI: 10.1007/s10930-022-10086-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/18/2022] [Indexed: 12/23/2022]
Abstract
Ginkgo seed is an important Chinese medicine and food resource in China, but the toxicity of ginkgo acid in it limits its application. Previous studies have found that salicylic acid decarboxylase (Sdc) has a decarboxylation degradation effect on ginkgo acid. In order to improve the decarboxylation ability of Sdc to Ginkgo acid, 11 residues of the Sdc around the substrate (salicylic acid) were determined as mutation targets according to the analysis of crystal structure of Sdc (PDB ID:6JQX), from Trichosporon moniliiforme WU-0401, and a total of 30 single point mutant enzymes and one compound mutant enzyme were obtained. With Ginkgo acid C15:1 as the substrate, it was found from activity assay that Sdc-Y64T and Sdc-P191A had higher decarboxylation activity, which increased by 105.18% and 116.74% compared with that of wild type Sdc, respectively. The optimal pH for Sdc Y64T and Sdc-P191A to decarboxylate Ginkgo acid C15:1 was 5.5, which is the same as the wild type Sdc. The optimal temperature of Sdc-P191A was 50 °C, which was consistent with that of the wild type Sdc, but the optimal temperature of the mutant Sdc-Y64T was 40 °C, which was 10 °C lower than that of wild type Sdc.
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Affiliation(s)
- Yuanyuan Song
- Tianjin Key Laboratory of Industrial Microbiology, Teda Campus, Tianjin University of Science and Technology, No. 9 of 13th Street, Tianjin Economic and Technological Development Zone TEDA, Tianjin, 300457, People's Republic of China
| | - Yanying Hu
- Jining University, Xingtan Road, New District, Qufu City, Shandong Province, People's Republic of China
| | - Jiaxin Li
- Tianjin Key Laboratory of Industrial Microbiology, Teda Campus, Tianjin University of Science and Technology, No. 9 of 13th Street, Tianjin Economic and Technological Development Zone TEDA, Tianjin, 300457, People's Republic of China
| | - Lin Wang
- Tianjin Key Laboratory of Industrial Microbiology, Teda Campus, Tianjin University of Science and Technology, No. 9 of 13th Street, Tianjin Economic and Technological Development Zone TEDA, Tianjin, 300457, People's Republic of China
| | - Wenjie Jing
- Tianjin Key Laboratory of Industrial Microbiology, Teda Campus, Tianjin University of Science and Technology, No. 9 of 13th Street, Tianjin Economic and Technological Development Zone TEDA, Tianjin, 300457, People's Republic of China
| | - Liming Zhang
- Tianjin Key Laboratory of Industrial Microbiology, Teda Campus, Tianjin University of Science and Technology, No. 9 of 13th Street, Tianjin Economic and Technological Development Zone TEDA, Tianjin, 300457, People's Republic of China
| | - Yujie Dai
- Tianjin Key Laboratory of Industrial Microbiology, Teda Campus, Tianjin University of Science and Technology, No. 9 of 13th Street, Tianjin Economic and Technological Development Zone TEDA, Tianjin, 300457, People's Republic of China.
| | - Shiru Jia
- Tianjin Key Laboratory of Industrial Microbiology, Teda Campus, Tianjin University of Science and Technology, No. 9 of 13th Street, Tianjin Economic and Technological Development Zone TEDA, Tianjin, 300457, People's Republic of China
| | - Xuan Meng
- Tianjin Key Laboratory of Industrial Microbiology, Teda Campus, Tianjin University of Science and Technology, No. 9 of 13th Street, Tianjin Economic and Technological Development Zone TEDA, Tianjin, 300457, People's Republic of China
| | - Huitu Zhang
- Tianjin Key Laboratory of Industrial Microbiology, Teda Campus, Tianjin University of Science and Technology, No. 9 of 13th Street, Tianjin Economic and Technological Development Zone TEDA, Tianjin, 300457, People's Republic of China
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4
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Abstract
Major histocompatibility complex (MHC) proteins are the most polymorphic and polygenic proteins in humans. They bind peptides, derived from cleavage of different pathogenic antigens, and are responsible for presenting them to T cells. The peptides recognized by the T cell receptors are denoted as epitopes and they trigger an immune response.In this chapter, we describe a docking protocol for predicting the peptide binding to a given MHC protein using the software tool GOLD. The protocol starts with the construction of a combinatorial peptide library used in the docking and ends with the derivation of a quantitative matrix (QM) accounting for the contribution of each amino acid at each peptide position.
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5
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Ceni C, Benko MJ, Mohamed KA, Poli G, Di Stefano M, Tuccinardi T, Digiacomo M, Valoti M, Laprairie RB, Macchia M, Bertini S. Novel Potent and Selective Agonists of the GPR55 Receptor Based on the 3-Benzylquinolin-2(1H)-One Scaffold. Pharmaceuticals (Basel) 2022; 15:ph15070768. [PMID: 35890067 PMCID: PMC9320067 DOI: 10.3390/ph15070768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/08/2022] [Accepted: 06/17/2022] [Indexed: 11/16/2022] Open
Abstract
A growing body of evidence underlines the crucial role of GPR55 in physiological and pathological conditions. In fact, GPR55 has recently emerged as a therapeutic target for several diseases, including cancer and neurodegenerative and metabolic disorders. Several lines of evidence highlight GPR55′s involvement in the regulation of microglia-mediated neuroinflammation, although the exact molecular mechanism has not been yet elucidated. Nevertheless, there are only a limited number of selective GPR55 ligands reported in the literature. In this work, we designed and synthesized a series of novel GPR55 ligands based on the 3-benzylquinolin-2(1H)-one scaffold, some of which showed excellent binding properties (with Ki values in the low nanomolar range) and almost complete selectivity over cannabinoid receptors. The full agonist profile of all the new derivatives was assessed using the p-ERK activation assay and a computational study was conducted to predict the key interactions with the binding site of the receptor. Our data outline a preliminary structure–activity relationship (SAR) for this class of molecules at GPR55. Some of our compounds are among the most potent GPR55 agonists developed to date and could be useful as tools to validate this receptor as a therapeutic target.
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Affiliation(s)
- Costanza Ceni
- Department of Pharmacy, University of Pisa, Via Bonanno Pisano 6, 56126 Pisa, Italy
- Doctoral School in Life Sciences, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Michael J Benko
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Kawthar A Mohamed
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Giulio Poli
- Department of Pharmacy, University of Pisa, Via Bonanno Pisano 6, 56126 Pisa, Italy
| | - Miriana Di Stefano
- Department of Pharmacy, University of Pisa, Via Bonanno Pisano 6, 56126 Pisa, Italy
- Doctoral School in Life Sciences, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Tiziano Tuccinardi
- Department of Pharmacy, University of Pisa, Via Bonanno Pisano 6, 56126 Pisa, Italy
| | - Maria Digiacomo
- Department of Pharmacy, University of Pisa, Via Bonanno Pisano 6, 56126 Pisa, Italy
| | - Massimo Valoti
- Department of Life Sciences, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Robert B Laprairie
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Marco Macchia
- Department of Pharmacy, University of Pisa, Via Bonanno Pisano 6, 56126 Pisa, Italy
| | - Simone Bertini
- Department of Pharmacy, University of Pisa, Via Bonanno Pisano 6, 56126 Pisa, Italy
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6
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Abstract
Valerena-1,10-diene synthase (VDS) catalyzes the conversion of the universal precursor farnesyl diphosphate into the unusual sesquiterpene valerena-1,10-diene (VLD), which possesses a unique isobutenyl substituent group. In planta, one of VLD's isobutenyl terminal methyl groups becomes oxidized to a carboxylic acid forming valerenic acid (VA), an allosteric modulator of the GABAA receptor. Because a structure-activity relationship study of VA for its modulatory activity is desired, we sought to manipulate the VDS enzyme for the biosynthesis of structurally diverse scaffolds that could ultimately lead to the generation of VA analogues. Using three-dimensional structural homology models, phylogenetic sequence comparisons to well-characterized sesquiterpene synthases, and a substrate-active site contact mapping approach, the contributions of specific amino acid residues within or near the VDS active site to possible catalytic cascades for VLD and other sesquiterpene products were assessed. An essential role of Tyr535 in a germacrenyl route to VLD was demonstrated, while its contribution to a family of other sesquiterpenes derived from a humulyl route was not. No role for Cys415 or Cys452 serving as a proton donor to reaction intermediates in VLD biosynthesis was observed. However, a gatekeeper role for Asn455 in directing farnesyl carbocations down all-trans catalytic cascades (humulyl and germacrenyl routes) versus a cisoid cascade (nerolidyl route) was demonstrated. Altogether, these results have mapped residues that establish a context for the catalytic cascades operating in VDS and future manipulations for generating more structurally constrained scaffolds.
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Affiliation(s)
- Garrett E Zinck
- Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, Kentucky 40536-0596, United States
| | - Joe Chappell
- Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, Kentucky 40536-0596, United States
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7
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Recent Advances in In Silico Target Fishing. Molecules 2021; 26:molecules26175124. [PMID: 34500568 PMCID: PMC8433825 DOI: 10.3390/molecules26175124] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/14/2021] [Accepted: 08/18/2021] [Indexed: 12/24/2022] Open
Abstract
In silico target fishing, whose aim is to identify possible protein targets for a query molecule, is an emerging approach used in drug discovery due its wide variety of applications. This strategy allows the clarification of mechanism of action and biological activities of compounds whose target is still unknown. Moreover, target fishing can be employed for the identification of off targets of drug candidates, thus recognizing and preventing their possible adverse effects. For these reasons, target fishing has increasingly become a key approach for polypharmacology, drug repurposing, and the identification of new drug targets. While experimental target fishing can be lengthy and difficult to implement, due to the plethora of interactions that may occur for a single small-molecule with different protein targets, an in silico approach can be quicker, less expensive, more efficient for specific protein structures, and thus easier to employ. Moreover, the possibility to use it in combination with docking and virtual screening studies, as well as the increasing number of web-based tools that have been recently developed, make target fishing a more appealing method for drug discovery. It is especially worth underlining the increasing implementation of machine learning in this field, both as a main target fishing approach and as a further development of already applied strategies. This review reports on the main in silico target fishing strategies, belonging to both ligand-based and receptor-based approaches, developed and applied in the last years, with a particular attention to the different web tools freely accessible by the scientific community for performing target fishing studies.
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8
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Biological Profiling of Semisynthetic C19-Functionalized Ferruginol and Sugiol Analogues. Antibiotics (Basel) 2021; 10:antibiotics10020184. [PMID: 33673350 PMCID: PMC7918733 DOI: 10.3390/antibiotics10020184] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/10/2021] [Accepted: 02/10/2021] [Indexed: 12/17/2022] Open
Abstract
The abietane-type diterpenoids are significant bioactive compounds exhibiting a varied range of pharmacological properties. In this study, the first synthesis and biological investigation of the new abietane-diterpenoid (+)-4-epi-liquiditerpenoid acid (8a) together with several of its analogs are reported. The compounds were generated from the readily available methyl callitrisate (7), which was obtained from callitrisic acid present in Moroccan Sandarac resin. A biological evaluation was conducted to determine the effects of the different functional groups present in these molecules, providing basic structure-activity relationship (SAR) elements. In particular, the ferruginol and sugiol analogs compounds 10-16 were characterized by the presence of a phenol moiety, higher oxidization states at C-7 (ketone), and the hydroxyl, methyl ester or free carboxylic acid at C19. The biological profiling of these compounds was investigated against a panel of six human solid tumor cell lines (HBL-100, A549, HeLa, T-47D, SW1573 and WiDr), four parasitic Leishmania species (L. donovani, L. infantum, L. guyanensis and L. amazonensis) and two malaria strains (3D7 and K1). Furthermore, the capacity of the compounds to modulate gamma-aminobutyric acid type A (GABAA) receptors (α1β2γ2s) is also described. A comparison of the biological results with those previously reported of the corresponding C18-functionalized analogs was conducted.
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9
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Wang PF, Jensen AA, Bunch L. From Methaqualone and Beyond: Structure-Activity Relationship of 6-, 7-, and 8-Substituted 2,3-Diphenyl-quinazolin-4(3 H)-ones and in Silico Prediction of Putative Binding Modes of Quinazolin-4(3 H)-ones as Positive Allosteric Modulators of GABA A Receptors. ACS Chem Neurosci 2020; 11:4362-4375. [PMID: 33170625 DOI: 10.1021/acschemneuro.0c00600] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Methaqualone (2-methyl-3-(o-tolyl)-quinazolin-4(3H)-one, MTQ) is a moderately potent positive allosteric modulator (PAM) of GABAA receptors (GABAARs). In a previous structure-activity relationship (SAR) study probing the importance of 2- and 3-substituents in the quinazolin-4(3H)-one scaffold, several potent GABAAR PAMs were identified, including 2,3-diphenylquinazolin-4(3H)-one (PPQ) and 3-(2-chlorophenyl)-2-phenylquinazolin-4(3H)-one (Cl-PPQ). Here, PPQ was applied as lead in a SAR study of 6-, 7-, and 8-substituents in the quinazolin-4(3H)-one by synthesis and functional characterization of 36 PPQ analogs at various GABAAR subtypes. While none of the new analogs were significantly more potent than PPQ or displayed pronounced subtype selectivity across the GABAARs tested, several interesting SAR observations were extracted from the study. In an in silico study, the putative binding modes of MTQ, PPQ, and Cl-PPQ in the transmembrane β2(+)/α1(-) interface of the α1β2γ2S GABAAR were predicted. Several plausible binding modes were identified for the three PAMs, and rationalization of the molecular basis for their different modulatory potencies was attempted.
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Affiliation(s)
- Peng-Fei Wang
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
- School of Pharmaceutical Sciences and Innovative Drug Research Centre, Chongqing University, Chongqing 400044, P.R. China
| | - Anders A. Jensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
| | - Lennart Bunch
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark
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10
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jain N, Singour PK. Novel 3-Substituted-2, 3-Dihydro-2-Thioxoquinazolin-4-(1H)-one derivative as Anticonvulsants: Synthesis, Molecular Docking and Pharmacological Screening. LETT DRUG DES DISCOV 2020. [DOI: 10.2174/1570180816666191024090857] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Background:
According to the World Health Organization, 50 million people worldwide
are suffering from epilepsy, making it one of the most common neurological diseases globally. 2,3
disubstituted quinazolinone-4-one derivatives endowed with various pharmacological activity, particularly
having anticonvulsant action.
Objectives:
The aim of this study was to synthesize 3-Substituted-2,3-Dihydro-2-thioxoquinazolin-
4-(1H)-one derivative and evaluate for anticonvulsant activity and neurotoxicity in order to find an
efficient, compound with lesser side effects.
Methods:
A novel series of 3-[4-(2-amino-5, 6-dihydro-4(substituted phenyl)-4H-1, 3-oxazin
/thiazin-6yl) phenyl]-2, 3-dihyro-2-thioxoquinazolin-4(1H)-one derivatives (4a-4p) were synthesized.
The structures of the synthesized compounds were assigned on the basis of spectral data (UV,
IR, 1HNMR, 13CNMR and MS) and performed anticonvulsant activity against maximal electroshock
test and Subcutaneous Pentylenetetrazole model. Neurotoxicity was assessed using a rotarod apparatus
test. The molecular docking study was performed to assess their binding affinities towards
Gamma-Aminobutyric Acid type A receptor. A quantitative estimate of drug-likeness was also performed,
which calculates the molecular properties and screen the molecules based on drug-likeness
rules.
Results:
Compounds 4b, 4e, 4j and 4m have shown the highest anticonvulsant activity against tonic
seizure with decreased mean duration of tonic hind leg extension of 8.31, 7.35, 8.61 and 8.99 s, respectively
in maximal electroshock model and increased onset time clonic convulsion duration of
94.45, 96.65, 93.51 and 91.86 s in Subcutaneous Pentylenetetrazole model. Molecular docking study
revealed a better binding affinity with Gamma-Aminobutyric Acid type A receptor.
Conclusion:
The compound 4b and 4e emerged out as the pilot molecule with a better anticonvulsant
activity without any neurotoxicity. The obtained results showed that compounds 4b and 4e
could be useful as a template for future design, optimization, and investigation to produce more active
analogs.
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Affiliation(s)
- Nimisha jain
- Computational & Synthetic Chemistry Division, Department of Pharmaceutical Chemistry, Faculty of Pharmacy, VNS Group of Institutions, Neelbud, Bhopal 462023 (M.P.), India
| | - Pradeep Kumar Singour
- Computational & Synthetic Chemistry Division, Department of Pharmaceutical Chemistry, Faculty of Pharmacy, VNS Group of Institutions, Neelbud, Bhopal 462023 (M.P.), India
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11
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Rodríguez-Cruz A, Romo-Mancillas A, Mendiola-Precoma J, Escobar-Cabrera JE, García-Alcocer G, Berumen LC. "Effect of valerenic acid on neuroinflammation in a MPTP-induced mouse model of Parkinson's disease". IBRO Rep 2020; 8:28-35. [PMID: 31909290 PMCID: PMC6938966 DOI: 10.1016/j.ibror.2019.12.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 12/11/2019] [Indexed: 12/20/2022] Open
Abstract
Parkinson´s disease is the most important neuromotor pathology due to the prominent loss of dopaminergic neurons in the substantia nigra pars compacta. There is an inherent deficiency of dopamine in Parkinson´s disease, which is aggravated when neuroinflammatory processes are present. Several biomolecules are interesting candidates for the regulation of inflammation and possible neuroprotection, such as valerenic acid, one of the main components of Valeriana officinalis. A 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP)-induced mouse model of Parkinson's disease was developed to evaluate the motor effects of valerenic acid. The evaluation was carried out with four tests (an invert screen test for muscle strength, cross beam test, open field mobility test and lifting on hind legs test). Subsequently, the neuroinflammatory process was evaluated through ELISA of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α and IFN-γ). The decreases in the inflammatory and neurodegenerative processes were evaluated by Western blot and immunohistochemistry analyses of the tissues, which included an evaluation of the tyrosine hydroxylase and GFAP proteins. Finally, the predicted mechanism of action of valerenic acid was supported by molecular docking calculations with the 5-HT5A receptor. The results indicate that the use of valerenic acid as a co-treatment decreases the neuroinflammation in Parkinson's disease induced by MPTP and provides evidence of a decrease in the evaluated pro-inflammatory cytokines and in the amount of GFAP in the mesencephalic area. Valerenic acid prevents neuroinflammation in a Parkinson's disease mouse model, which might reflect the neuroprotection of dopaminergic neurons with the recovery of motor ability.
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Affiliation(s)
- Alfredo Rodríguez-Cruz
- Laboratorio de Investigación Genética, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Mexico
- Posgrado en Ciencias Químico-Biológicas, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Mexico
| | - Antonio Romo-Mancillas
- Posgrado en Ciencias Químico-Biológicas, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Mexico
- Laboratorio de Diseño Asistido por Computadora y Síntesis de Fármacos, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Mexico
| | - Jesus Mendiola-Precoma
- Laboratorio de Investigación Genética, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Mexico
- Posgrado en Ciencias Químico-Biológicas, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Mexico
| | - Jesica Esther Escobar-Cabrera
- Laboratorio de Investigación Genética, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Mexico
- Posgrado en Ciencias Químico-Biológicas, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Mexico
| | - Guadalupe García-Alcocer
- Laboratorio de Investigación Genética, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Mexico
- Posgrado en Ciencias Químico-Biológicas, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Mexico
| | - Laura Cristina Berumen
- Laboratorio de Investigación Genética, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Mexico
- Posgrado en Ciencias Químico-Biológicas, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Mexico
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12
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Jain N, Singour PK. Novel 3-{4-[2-Amino-4-(Substitutedphenyl)-2H-[1, 3] Oxazin/Thiazin-6-Yl} -2-Phenyl-3H-Quinazolin-4-One Derivatives as Enhancer of GABA Mediated Inhibition: Synthesis, Molecular Modeling and Pharmacological Studies. LETT DRUG DES DISCOV 2020. [DOI: 10.2174/1570180816666190222155404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Background:
According to WHO, the 50 million people worldwide are suffering from
epilepsy, making it one of the most common neurological diseases globally. Epilepsy is often
characterized by neurobiological, cognitive, psychological and behavioral changes and that may
enhance the susceptibility to seizures and affect the quality of life.
Objective:
The aim of the present work was to develop 2, 3 disubstituted 4-(3H)-quinazolinone
derivatives in order to find an effective and highly lipophilic compound with lesser side effects and
to evaluate them for anticonvulsant and neurotoxic activity.
Methods:
A novel series of 3-4-[2-amino-4-(substitutedphenyl)-2H-[1.3] oxazin/thiazin-6-yl 2-
phenyl-3H-quinazolin-4-one derivatives were synthesized and evaluated for their anticonvulsant
activity. The structures of the compound have been confirmed by spectral analysis. The molecular
docking study was performed for finding the binding affinity with GABAA receptor in order to
rationalize their anticonvulsant activities in a qualitative way. Quantitative estimate of drug-likeness
was also performed which calculate the molecular properties and screen the molecules based on
drug-likeness rules. Anticonvulsant activities of synthesized compounds were done by using
(Maximal electroshock) MES induced seizures and subcutaneous pentylenetetrazole (scPTZ) induced
seizure models in Wistar rats of either sex. None of the compounds demonstrated any sign of
neurotoxicity.
Results:
Compounds 3-4-[2-amino-4-(fluorophenyl)-2H- [1, 3] oxazin-6-yl 2-phenyl-3H
quinazolin-4-one (5i) and 3-4-[2-amino-4-(fluorophenyl)-2H- [1, 3] thiazin -6-yl 2-phenyl-3H
quinazolin-4-one (5n) have shown significant activity against tonic seizure by the MES model and
clonic seizure by scPTZ induced seizure model.
Conclusion:
These ten novels synthesized compounds had significant anticonvulsant activity. As a
result, the compound (5i) and (5n) emerged out as the pilot molecule with a better anticonvulsant
activity without any neurotoxicity, while the other compounds have moderate activity. QED analysis
of compounds (5i) and (5n) also indicated that these compounds will have good oral absorption. The
proposed work is to make efforts towards the development and identification of novel molecules as
anticonvulsant agents by the synthesis of some novel quinazolinone derivatives with improved
biological activity.
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Affiliation(s)
- Nimisha Jain
- Department of Pharmaceutical Chemistry, Computational and Synthetic Chemistry Division, Faculty of Pharmacy,VNS Group of Institutions, Neelbud, Bhopal 462023 (M.P.), India
| | - Pradeep Kumar Singour
- Department of Pharmaceutical Chemistry, Computational and Synthetic Chemistry Division, Faculty of Pharmacy,VNS Group of Institutions, Neelbud, Bhopal 462023 (M.P.), India
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13
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Carpi S, Scoditti E, Massaro M, Polini B, Manera C, Digiacomo M, Esposito Salsano J, Poli G, Tuccinardi T, Doccini S, Santorelli FM, Carluccio MA, Macchia M, Wabitsch M, De Caterina R, Nieri P. The Extra-Virgin Olive Oil Polyphenols Oleocanthal and Oleacein Counteract Inflammation-Related Gene and miRNA Expression in Adipocytes by Attenuating NF-κB Activation. Nutrients 2019; 11:nu11122855. [PMID: 31766503 PMCID: PMC6950227 DOI: 10.3390/nu11122855] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 11/13/2019] [Accepted: 11/19/2019] [Indexed: 12/21/2022] Open
Abstract
Inflammation of the adipose tissue plays an important role in the development of several chronic diseases associated with obesity. Polyphenols of extra virgin olive oil (EVOO), such as the secoiridoids oleocanthal (OC) and oleacein (OA), have many nutraceutical proprieties. However, their roles in obesity-associated adipocyte inflammation, the NF-κB pathway and related sub-networks have not been fully elucidated. Here, we investigated impact of OC and OA on the activation of NF-κB and the expression of molecules associated with inflammatory and dysmetabolic responses. To this aim, fully differentiated Simpson-Golabi-Behmel syndrome (SGBS) adipocytes were pre-treated with OC or OA before stimulation with TNF-α. EVOO polyphenols significantly reduced the expression of genes implicated in adipocyte inflammation (IL-1β, COX-2), angiogenesis (VEGF/KDR, MMP-2), oxidative stress (NADPH oxidase), antioxidant enzymes (SOD and GPX), leukocytes chemotaxis and infiltration (MCP-1, CXCL-10, MCS-F), and improved the expression of the anti-inflammatory/metabolic effector PPARγ. Accordingly, miR-155-5p, miR-34a-5p and let-7c-5p, tightly connected with the NF-κB pathway, were deregulated by TNF-α in both cells and exosomes. The miRNA modulation and NF-κB activation by TNF-α was significantly counteracted by EVOO polyphenols. Computational studies suggested a potential direct interaction between OC and NF-κB at the basis of its activity. This study demonstrates that OC and OA counteract adipocyte inflammation attenuating NF-κB activation. Therefore, these compounds could be novel dietary tools for the prevention of inflammatory diseases associated with obesity.
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Affiliation(s)
- Sara Carpi
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy; (B.P.); (C.M.); (M.D.); (J.E.S.); (G.P.); (T.T.); (M.M.); (P.N.)
- Interdepartmental Research Center “Nutraceuticals and Food for Health” University of Pisa, 56124 Pisa, Italy
- Correspondence: ; Tel.: +39-050-2219597
| | - Egeria Scoditti
- National Research Council (CNR) Institute of Clinical Physiology (IFC), 73100 Lecce, Italy; (E.S.); (M.M.); (M.A.C.)
| | - Marika Massaro
- National Research Council (CNR) Institute of Clinical Physiology (IFC), 73100 Lecce, Italy; (E.S.); (M.M.); (M.A.C.)
| | - Beatrice Polini
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy; (B.P.); (C.M.); (M.D.); (J.E.S.); (G.P.); (T.T.); (M.M.); (P.N.)
| | - Clementina Manera
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy; (B.P.); (C.M.); (M.D.); (J.E.S.); (G.P.); (T.T.); (M.M.); (P.N.)
- Interdepartmental Research Center “Nutraceuticals and Food for Health” University of Pisa, 56124 Pisa, Italy
| | - Maria Digiacomo
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy; (B.P.); (C.M.); (M.D.); (J.E.S.); (G.P.); (T.T.); (M.M.); (P.N.)
- Interdepartmental Research Center “Nutraceuticals and Food for Health” University of Pisa, 56124 Pisa, Italy
| | - Jasmine Esposito Salsano
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy; (B.P.); (C.M.); (M.D.); (J.E.S.); (G.P.); (T.T.); (M.M.); (P.N.)
- Doctoral School in Life Sciences, University of Siena, 53100 Siena, Italy
| | - Giulio Poli
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy; (B.P.); (C.M.); (M.D.); (J.E.S.); (G.P.); (T.T.); (M.M.); (P.N.)
| | - Tiziano Tuccinardi
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy; (B.P.); (C.M.); (M.D.); (J.E.S.); (G.P.); (T.T.); (M.M.); (P.N.)
| | - Stefano Doccini
- Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, IRCCS Fondazione Stella Maris, Calambrone, 56128 Pisa, Italy; (S.D.); (F.M.S.)
| | - Filippo Maria Santorelli
- Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, IRCCS Fondazione Stella Maris, Calambrone, 56128 Pisa, Italy; (S.D.); (F.M.S.)
| | - Maria Annunziata Carluccio
- National Research Council (CNR) Institute of Clinical Physiology (IFC), 73100 Lecce, Italy; (E.S.); (M.M.); (M.A.C.)
| | - Marco Macchia
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy; (B.P.); (C.M.); (M.D.); (J.E.S.); (G.P.); (T.T.); (M.M.); (P.N.)
- Interdepartmental Research Center “Nutraceuticals and Food for Health” University of Pisa, 56124 Pisa, Italy
| | - Martin Wabitsch
- Division of Pediatric Endocrinology, Diabetes and Obesity, Department of Pediatrics and Adolescent Medicine, University of Ulm, 89075 Ulm, Germany;
| | | | - Paola Nieri
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy; (B.P.); (C.M.); (M.D.); (J.E.S.); (G.P.); (T.T.); (M.M.); (P.N.)
- Interdepartmental Research Center “Nutraceuticals and Food for Health” University of Pisa, 56124 Pisa, Italy
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14
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Discovery of Novel µ-Opioid Receptor Inverse Agonist from a Combinatorial Library of Tetrapeptides through Structure-Based Virtual Screening. Molecules 2019; 24:molecules24213872. [PMID: 31717871 PMCID: PMC6865014 DOI: 10.3390/molecules24213872] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 10/24/2019] [Accepted: 10/26/2019] [Indexed: 11/18/2022] Open
Abstract
Morphine, oxycodone, fentanyl, and other µ-opioid receptors (MOR) agonists have been used for decades in antinociceptive therapies. However, these drugs are associated with numerous side effects, such as euphoria, addiction, respiratory depression, and adverse gastrointestinal reactions, thus, circumventing these drawbacks is of extensive importance. With the aim of identifying novel peptide ligands endowed with MOR inhibitory activity, we developed a virtual screening protocol, including receptor-based pharmacophore screening, docking studies, and molecular dynamics simulations, which was used to filter an in-house built virtual library of tetrapeptide ligands. The three top-scored compounds were synthesized and subjected to biological evaluation, revealing the identity of a hit compound (peptide 1) endowed with appreciable MOR inverse agonist effect and selectivity over δ-opioid receptors. These results confirmed the reliability of our computational approach and provided a promising starting point for the development of new potent MOR modulators.
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15
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Stadler M, Monticelli S, Seidel T, Luger D, Salzer I, Boehm S, Holzer W, Schwarzer C, Urban E, Khom S, Langer T, Pace V, Hering S. Design, Synthesis, and Pharmacological Evaluation of Novel β2/3 Subunit-Selective γ-Aminobutyric Acid Type A (GABA A) Receptor Modulators. J Med Chem 2018; 62:317-341. [PMID: 30289721 DOI: 10.1021/acs.jmedchem.8b00859] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Subunit-selective modulation of γ-aminobutyric acid type A receptors (GABAAR) is considered to exert fewer side effects compared to unselective clinically used drugs. Here, the β2/3 subunit-selective GABAAR modulators valerenic acid (VA) and loreclezole (LOR) guided the synthesis of novel subunit-selective ligands with simplified structures. We studied their effects on GABAARs expressed in Xenopus laevis oocytes using two-microelectrode voltage clamp technique. Five compounds showed significantly more efficacious modulation of GABA-evoked currents than VA and LOR with retained potency and selectivity. Compound 18 [( E)-2-Cyano-3-(2,4-dichlorophenyl)but-2-enamide] induced the highest maximal modulation of GABA-induced chloride currents ( Emax: 3114 ± 242%), while 12 [( Z)-3-(2,4-dichlorophenyl)but-2-enenitrile] displayed the highest potency (EC50: 13 ± 2 μM). Furthermore, in hippocampal neurons 12 facilitated phasic and tonic GABAergic inhibition, and in vivo studies revealed significantly more potent protection against pentylenetetrazole (PTZ)-induced seizures compared to VA and LOR. Collectively, compound 12 constitutes a novel, simplified, and subunit-selective GABAAR modulator with low-dose anticonvulsant activity.
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Affiliation(s)
- Marco Stadler
- Department of Pharmacology and Toxicology , University of Vienna , Althanstraße 14 , 1090 Vienna , Austria
| | - Serena Monticelli
- Department of Pharmaceutical Chemistry , University of Vienna , Althanstraße 14 , 1090 Vienna , Austria
| | - Thomas Seidel
- Department of Pharmaceutical Chemistry , University of Vienna , Althanstraße 14 , 1090 Vienna , Austria
| | - Denise Luger
- Department of Pharmacology and Toxicology , University of Vienna , Althanstraße 14 , 1090 Vienna , Austria
| | - Isabella Salzer
- Department of Neurophysiology and Neuropharmacology , Medical University Vienna , Schwarzspanierstraße 17 , 1090 Vienna , Austria
| | - Stefan Boehm
- Department of Neurophysiology and Neuropharmacology , Medical University Vienna , Schwarzspanierstraße 17 , 1090 Vienna , Austria
| | - Wolfgang Holzer
- Department of Pharmaceutical Chemistry , University of Vienna , Althanstraße 14 , 1090 Vienna , Austria
| | - Christoph Schwarzer
- Department of Pharmacology , Medical University Innsbruck , Peter-Mayr-Straße 1a , 6020 Innsbruck , Austria
| | - Ernst Urban
- Department of Pharmaceutical Chemistry , University of Vienna , Althanstraße 14 , 1090 Vienna , Austria
| | - Sophia Khom
- Department of Pharmacology and Toxicology , University of Vienna , Althanstraße 14 , 1090 Vienna , Austria.,Department of Neuroscience , The Scripps Research Institute , 10550 N Torrey Pines Road , La Jolla , California 92037 , United States
| | - Thierry Langer
- Department of Pharmaceutical Chemistry , University of Vienna , Althanstraße 14 , 1090 Vienna , Austria
| | - Vittorio Pace
- Department of Pharmaceutical Chemistry , University of Vienna , Althanstraße 14 , 1090 Vienna , Austria
| | - Steffen Hering
- Department of Pharmacology and Toxicology , University of Vienna , Althanstraße 14 , 1090 Vienna , Austria
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16
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Delineation of the functional properties and the mechanism of action of AA29504, an allosteric agonist and positive allosteric modulator of GABA A receptors. Biochem Pharmacol 2018; 150:305-319. [DOI: 10.1016/j.bcp.2018.02.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 02/13/2018] [Indexed: 11/22/2022]
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17
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Nybo SE, Saunders J, McCormick SP. Metabolic engineering of Escherichia coli for production of valerenadiene. J Biotechnol 2017; 262:60-66. [DOI: 10.1016/j.jbiotec.2017.10.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Revised: 10/03/2017] [Accepted: 10/04/2017] [Indexed: 01/25/2023]
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18
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Milanos S, Elsharif SA, Janzen D, Buettner A, Villmann C. Metabolic Products of Linalool and Modulation of GABA A Receptors. Front Chem 2017; 5:46. [PMID: 28680877 PMCID: PMC5478857 DOI: 10.3389/fchem.2017.00046] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 06/12/2017] [Indexed: 12/15/2022] Open
Abstract
Terpenoids are major subcomponents in aroma substances which harbor sedative physiological potential. We have demonstrated that various monoterpenoids such as the acyclic linalool enhance GABAergic currents in an allosteric manner in vitro upon overexpression of inhibitory α1β2 GABAA receptors in various expression systems. However, in plants or humans, i.e., following intake via inhalation or ingestion, linalool undergoes metabolic modifications including oxygenation and acetylation, which may affect the modulatory efficacy of the generated linalool derivatives. Here, we analyzed the modulatory potential of linalool derivatives at α1β2γ2 GABAA receptors upon transient overexpression. Following receptor expression control, electrophysiological recordings in a whole cell configuration were used to determine the chloride influx upon co-application of GABA EC10−30 together with the modulatory substance. Our results show that only oxygenated linalool metabolites at carbon 8 positively affect GABAergic currents whereas derivatives hydroxylated or carboxylated at carbon 8 were rather ineffective. Acetylated linalool derivatives resulted in non-significant changes of GABAergic currents. We can conclude that metabolism of linalool reduces its positive allosteric potential at GABAA receptors compared to the significant potentiation effects of the parent molecule linalool itself.
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Affiliation(s)
- Sinem Milanos
- Institute of Clinical Neurobiology, Julius-Maximilians-University of WürzburgWürzburg, Germany.,Department of Chemistry and Pharmacy, Food Chemistry, Emil-Fischer-Center, Friedrich-Alexander-University Erlangen-NürnbergErlangen, Germany
| | - Shaimaa A Elsharif
- Department of Chemistry and Pharmacy, Food Chemistry, Emil-Fischer-Center, Friedrich-Alexander-University Erlangen-NürnbergErlangen, Germany
| | - Dieter Janzen
- Institute of Clinical Neurobiology, Julius-Maximilians-University of WürzburgWürzburg, Germany
| | - Andrea Buettner
- Department of Chemistry and Pharmacy, Food Chemistry, Emil-Fischer-Center, Friedrich-Alexander-University Erlangen-NürnbergErlangen, Germany.,Department of Sensory Analytics, Fraunhofer Institute for Process Engineering and PackagingFreising, Germany
| | - Carmen Villmann
- Institute of Clinical Neurobiology, Julius-Maximilians-University of WürzburgWürzburg, Germany
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19
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Sari S, Dalkara S, Kaynak FB, Reynisson J, Saraç S, Karakurt A. New Anti-Seizure (Arylalkyl)azole Derivatives: Synthesis,In VivoandIn SilicoStudies. Arch Pharm (Weinheim) 2017; 350. [DOI: 10.1002/ardp.201700043] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 03/20/2017] [Accepted: 03/27/2017] [Indexed: 12/19/2022]
Affiliation(s)
- Suat Sari
- Faculty of Pharmacy, Department of Pharmaceutical Chemistry; Hacettepe University; Ankara Turkey
| | - Sevim Dalkara
- Faculty of Pharmacy, Department of Pharmaceutical Chemistry; Hacettepe University; Ankara Turkey
| | - Filiz Betül Kaynak
- Faculty of Engineering, Department of Physics Engineering; Hacettepe University; Ankara Turkey
| | - Jóhannes Reynisson
- School of Chemical Sciences; University of Auckland; Auckland New Zealand
| | - Selma Saraç
- Faculty of Pharmacy, Department of Pharmaceutical Chemistry; Hacettepe University; Ankara Turkey
| | - Arzu Karakurt
- Faculty of Pharmacy, Department of Pharmaceutical Chemistry; Inonu University; Malatya Turkey
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20
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Puthenkalam R, Hieckel M, Simeone X, Suwattanasophon C, Feldbauer RV, Ecker GF, Ernst M. Structural Studies of GABAA Receptor Binding Sites: Which Experimental Structure Tells us What? Front Mol Neurosci 2016; 9:44. [PMID: 27378845 PMCID: PMC4910578 DOI: 10.3389/fnmol.2016.00044] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 05/25/2016] [Indexed: 01/23/2023] Open
Abstract
Atomic resolution structures of cys-loop receptors, including one of a γ-aminobutyric acid type A receptor (GABAA receptor) subtype, allow amazing insights into the structural features and conformational changes that these pentameric ligand-gated ion channels (pLGICs) display. Here we present a comprehensive analysis of more than 30 cys-loop receptor structures of homologous proteins that revealed several allosteric binding sites not previously described in GABAA receptors. These novel binding sites were examined in GABAA receptor homology models and assessed as putative candidate sites for allosteric ligands. Four so far undescribed putative ligand binding sites were proposed for follow up studies based on their presence in the GABAA receptor homology models. A comprehensive analysis of conserved structural features in GABAA and glycine receptors (GlyRs), the glutamate gated ion channel, the bacterial homologs Erwinia chrysanthemi (ELIC) and Gloeobacter violaceus GLIC, and the serotonin type 3 (5-HT3) receptor was performed. The conserved features were integrated into a master alignment that led to improved homology models. The large fragment of the intracellular domain that is present in the structure of the 5-HT3 receptor was utilized to generate GABAA receptor models with a corresponding intracellular domain fragment. Results of mutational and photoaffinity ligand studies in GABAA receptors were analyzed in the light of the model structures. This led to an assignment of candidate ligands to two proposed novel pockets, candidate binding sites for furosemide and neurosteroids in the trans-membrane domain were identified. The homology models can serve as hypotheses generators, and some previously controversial structural interpretations of biochemical data can be resolved in the light of the presented multi-template approach to comparative modeling. Crystal and cryo-EM microscopic structures of the closest homologs that were solved in different conformational states provided important insights into structural rearrangements of binding sites during conformational transitions. The impact of structural variation and conformational motion on the shape of the investigated binding sites was analyzed. Rules for best template and alignment choice were obtained and can generally be applied to modeling of cys-loop receptors. Overall, we provide an updated structure based view of ligand binding sites present in GABAA receptors.
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Affiliation(s)
- Roshan Puthenkalam
- Department of Molecular Neurosciences, Medical University of ViennaVienna, Austria
| | - Marcel Hieckel
- Department of Molecular Neurosciences, Medical University of ViennaVienna, Austria
| | - Xenia Simeone
- Department of Molecular Neurosciences, Medical University of ViennaVienna, Austria
| | | | - Roman V. Feldbauer
- Austrian Research Institute for Artificial Intelligence (OFAI)Vienna, Austria
| | - Gerhard F. Ecker
- Department of Pharmaceutical Chemistry, University of ViennaVienna, Austria
| | - Margot Ernst
- Department of Molecular Neurosciences, Medical University of ViennaVienna, Austria
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21
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Khom S, Hintersteiner J, Luger D, Haider M, Pototschnig G, Mihovilovic MD, Schwarzer C, Hering S. Analysis of β-Subunit-dependent GABAA Receptor Modulation and Behavioral Effects of Valerenic Acid Derivatives. J Pharmacol Exp Ther 2016; 357:580-90. [PMID: 27190170 PMCID: PMC4885513 DOI: 10.1124/jpet.116.232983] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Accepted: 04/06/2016] [Indexed: 12/30/2022] Open
Abstract
Valerenic acid (VA)-a β2/3-selective GABA type A (GABAA) receptor modulator-displays anxiolytic and anticonvulsive effects in mice devoid of sedation, making VA an interesting drug candidate. Here we analyzed β-subunit-dependent enhancement of GABA-induced chloride currents (IGABA) by a library of VA derivatives and studied their effects on pentylenetetrazole (PTZ)-induced seizure threshold and locomotion. Compound-induced IGABA enhancement was determined in oocytes expressing α1β1γ2S, α1β2γ2S, or α1β3γ2S receptors. Effects on seizure threshold and locomotion were studied using C57BL/6N mice and compared with saline-treated controls. β2/3-selective VA derivatives such as VA-amide (VA-A) modulating α1β3γ2S (VA-A: Emax = 972 ± 69%, n = 6, P < 0.05) and α1β2γ2S receptors (Emax = 1119 ± 72%, n = 6, P < 0.05) more efficaciously than VA (α1β3γ2S: VA: Emax = 632 ± 88%, n = 9 versus α1β2γ2S: VA: Emax = 721 ± 68%, n = 6) displayed significantly more pronounced seizure threshold elevation than VA (saline control: 40.4 ± 1.4 mg/kg PTZ versus VA 10 mg/kg: 49.0 ± 1.8 mg/kg PTZ versus VA-A 3 mg/kg: 57.9 ± 1.9 mg/kg PTZ, P < 0.05). Similarly, VA's methylamide (VA-MA) enhancing IGABA through β3-containing receptors more efficaciously than VA (Emax = 1043 ± 57%, P < 0.01, n = 6) displayed stronger anticonvulsive effects. Increased potency of IGABA enhancement and anticonvulsive effects at lower doses compared with VA were observed for VA-tetrazole (α1β3γ2S: VA-TET: EC50 = 6.0 ± 1.0 μM, P < 0.05; VA-TET: 0.3 mg/kg: 47.3 ± 0.5 mg/kg PTZ versus VA: 10 mg/kg: 49.0 ± 1.8 mg/kg PTZ, P < 0.05). At higher doses (≥10 mg/kg), VA-A, VA-MA, and VA-TET reduced locomotion. In contrast, unselective VA derivatives induced anticonvulsive effects only at high doses (30 mg/kg) or did not display any behavioral effects. Our data indicate that the β2/3-selective compounds VA-A, VA-MA, and VA-TET induce anticonvulsive effects at low doses (≤10 mg/kg), whereas impairment of locomotion was observed at doses ≥10 mg/kg.
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Affiliation(s)
- S Khom
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria (S.K., J.H., D.L., S.H.); Institute of Applied Synthetic Chemistry, TU Wien, Vienna, Austria (M.H., G.P., M.D.M.); and Department of Pharmacology, Medical University of Innsbruck, Innsbruck, Austria (C.S.)
| | - J Hintersteiner
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria (S.K., J.H., D.L., S.H.); Institute of Applied Synthetic Chemistry, TU Wien, Vienna, Austria (M.H., G.P., M.D.M.); and Department of Pharmacology, Medical University of Innsbruck, Innsbruck, Austria (C.S.)
| | - D Luger
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria (S.K., J.H., D.L., S.H.); Institute of Applied Synthetic Chemistry, TU Wien, Vienna, Austria (M.H., G.P., M.D.M.); and Department of Pharmacology, Medical University of Innsbruck, Innsbruck, Austria (C.S.)
| | - M Haider
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria (S.K., J.H., D.L., S.H.); Institute of Applied Synthetic Chemistry, TU Wien, Vienna, Austria (M.H., G.P., M.D.M.); and Department of Pharmacology, Medical University of Innsbruck, Innsbruck, Austria (C.S.)
| | - G Pototschnig
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria (S.K., J.H., D.L., S.H.); Institute of Applied Synthetic Chemistry, TU Wien, Vienna, Austria (M.H., G.P., M.D.M.); and Department of Pharmacology, Medical University of Innsbruck, Innsbruck, Austria (C.S.)
| | - M D Mihovilovic
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria (S.K., J.H., D.L., S.H.); Institute of Applied Synthetic Chemistry, TU Wien, Vienna, Austria (M.H., G.P., M.D.M.); and Department of Pharmacology, Medical University of Innsbruck, Innsbruck, Austria (C.S.)
| | - C Schwarzer
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria (S.K., J.H., D.L., S.H.); Institute of Applied Synthetic Chemistry, TU Wien, Vienna, Austria (M.H., G.P., M.D.M.); and Department of Pharmacology, Medical University of Innsbruck, Innsbruck, Austria (C.S.)
| | - S Hering
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria (S.K., J.H., D.L., S.H.); Institute of Applied Synthetic Chemistry, TU Wien, Vienna, Austria (M.H., G.P., M.D.M.); and Department of Pharmacology, Medical University of Innsbruck, Innsbruck, Austria (C.S.)
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22
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Maldifassi MC, Baur R, Pierce D, Nourmahnad A, Forman SA, Sigel E. Novel positive allosteric modulators of GABAA receptors with anesthetic activity. Sci Rep 2016; 6:25943. [PMID: 27198062 PMCID: PMC4873749 DOI: 10.1038/srep25943] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Accepted: 04/25/2016] [Indexed: 01/08/2023] Open
Abstract
GABAA receptors are the main inhibitory neurotransmitter receptors in the brain and are targets for numerous clinically important drugs such as benzodiazepines, anxiolytics and anesthetics. We previously identified novel ligands of the classical benzodiazepine binding pocket in α1β2γ2 GABAA receptors using an experiment-guided virtual screening (EGVS) method. This screen also identified novel ligands for intramembrane low affinity diazepam site(s). In the current study we have further characterized compounds 31 and 132 identified with EGVS as well as 4-O-methylhonokiol. We investigated the site of action of these compounds in α1β2γ2 GABAA receptors expressed in Xenopus laevis oocytes using voltage-clamp electrophysiology combined with a benzodiazepine site antagonist and transmembrane domain mutations. All three compounds act mainly through the two β+/α− subunit transmembrane interfaces of the GABAA receptors. We then used concatenated receptors to dissect the involvement of individual β+/α− interfaces. We further demonstrated that these compounds have anesthetic activity in a small aquatic animal model, Xenopus laevis tadpoles. The newly identified compounds may serve as scaffolds for the development of novel anesthetics.
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Affiliation(s)
- Maria C Maldifassi
- Institute of Biochemistry and Molecular Medicine, University of Bern, CH-3012 Bern, Switzerland
| | - Roland Baur
- Institute of Biochemistry and Molecular Medicine, University of Bern, CH-3012 Bern, Switzerland
| | - David Pierce
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, 02114 Massachusetts
| | - Anahita Nourmahnad
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, 02114 Massachusetts
| | - Stuart A Forman
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, 02114 Massachusetts
| | - Erwin Sigel
- Institute of Biochemistry and Molecular Medicine, University of Bern, CH-3012 Bern, Switzerland
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Luger D, Poli G, Wieder M, Stadler M, Ke S, Ernst M, Hohaus A, Linder T, Seidel T, Langer T, Khom S, Hering S. Identification of the putative binding pocket of valerenic acid on GABAA receptors using docking studies and site-directed mutagenesis. Br J Pharmacol 2015; 172:5403-13. [PMID: 26375408 PMCID: PMC4988470 DOI: 10.1111/bph.13329] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 08/25/2015] [Accepted: 08/30/2015] [Indexed: 12/15/2022] Open
Abstract
Background and Purpose β2/3‐subunit‐selective modulation of GABAA receptors by valerenic acid (VA) is determined by the presence of transmembrane residue β2/3N265. Currently, it is not known whether β2/3N265 is part of VA's binding pocket or is involved in the transduction pathway of VA's action. The aim of this study was to clarify the localization of VA's binding pocket on GABAA receptors. Experimental Approach Docking and a structure‐based three‐dimensional pharmacophore were employed to identify candidate amino acid residues that are likely to interact with VA. Selected amino acid residues were mutated, and VA‐induced modulation of the resulting GABAA receptors expressed in Xenopus oocytes was analysed. Key Results A binding pocket for VA at the β+/α− interface encompassing amino acid β3N265 was predicted. Mutational analysis of suggested amino acid residues revealed a complete loss of VA's activity on β3M286W channels as well as significantly decreased efficacy and potency of VA on β3N265S and β3F289S receptors. In addition, reduced efficacy of VA‐induced IGABA enhancement was also observed for α1M235W, β3R269A and β3M286A constructs. Conclusions and Implications Our data suggest that amino acid residues β3N265, β3F289, β3M286, β3R269 in the β3 subunit, at or near the etomidate/propofol binding site(s), form part of a VA binding pocket. The identification of the binding pocket for VA is essential for elucidating its pharmacological effects and might also help to develop new selective GABAA receptor ligands.
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Affiliation(s)
- D Luger
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
| | - G Poli
- Department of Pharmacy, University of Pisa, Pisa, Italy
| | - M Wieder
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - M Stadler
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
| | - S Ke
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
| | - M Ernst
- Department of Molecular Neurosciences, Center of Brain Research, Medical University of Vienna, Vienna, Austria
| | - A Hohaus
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
| | - T Linder
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
| | - T Seidel
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - T Langer
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - S Khom
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
| | - S Hering
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
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