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Exploring Biginelli-based scaffolds as A 2B adenosine receptor antagonists: Unveiling novel structure-activity relationship trends, lead compounds, and potent colorectal anticancer agents. Biomed Pharmacother 2024; 173:116345. [PMID: 38442670 DOI: 10.1016/j.biopha.2024.116345] [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: 12/18/2023] [Revised: 02/19/2024] [Accepted: 02/23/2024] [Indexed: 03/07/2024] Open
Abstract
Antagonists of the A2B adenosine receptor have recently emerged as targeted anticancer agents and immune checkpoint inhibitors within the realm of cancer immunotherapy. This study presents a comprehensive evaluation of novel Biginelli-assembled pyrimidine chemotypes, including mono-, bi-, and tricyclic derivatives, as A2BAR antagonists. We conducted a comprehensive examination of the adenosinergic profile (both binding and functional) of a large compound library consisting of 168 compounds. This approach unveiled original lead compounds and enabled the identification of novel structure-activity relationship (SAR) trends, which were supported by extensive computational studies, including quantum mechanical calculations and free energy perturbation (FEP) analysis. In total, 25 molecules showed attractive affinity (Ki < 100 nM) and outstanding selectivity for A2BAR. From these, five molecules corresponding to the new benzothiazole scaffold were below the Ki < 10 nM threshold, in addition to a novel dual A2A/A2B antagonist. The most potent compounds, and the dual antagonist, showed enantiospecific recognition in the A2BAR. Two A2BAR selective antagonists and the dual A2AAR/A2BAR antagonist reported in this study were assessed for their impact on colorectal cancer cell lines. The results revealed a significant and dose-dependent reduction in cell proliferation. Notably, the A2BAR antagonists exhibited remarkable specificity, as they did not impede the proliferation of non-tumoral cell lines. These findings support the efficacy and potential that A2BAR antagonists as valuable candidates for cancer therapy, but also that they can effectively complement strategies involving A2AAR antagonism in the context of immune checkpoint inhibition.
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Pharmacological insights emerging from the characterization of a large collection of synthetic cannabinoid receptor agonists designer drugs. Biomed Pharmacother 2023; 164:114934. [PMID: 37236027 DOI: 10.1016/j.biopha.2023.114934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 04/01/2023] [Accepted: 05/22/2023] [Indexed: 05/28/2023] Open
Abstract
Synthetic cannabinoid receptor agonists (SCRAs) constitute the largest and most defiant group of abuse designer drugs. These new psychoactive substances (NPS), developed as unregulated alternatives to cannabis, have potent cannabimimetic effects and their use is usually associated with episodes of psychosis, seizures, dependence, organ toxicity and death. Due to their ever-changing structure, very limited or nil structural, pharmacological, and toxicological information is available to the scientific community and the law enforcement offices. Here we report the synthesis and pharmacological evaluation (binding and functional) of the largest and most diverse collection of enantiopure SCRAs published to date. Our results revealed novel SCRAs that could be (or may currently be) used as illegal psychoactive substances. We also report, for the first time, the cannabimimetic data of 32 novel SCRAs containing an (R) configuration at the stereogenic center. The systematic pharmacological profiling of the library enabled the identification of emerging Structure-Activity Relationship (SAR) and Structure-Selectivity Relationship (SSR) trends, the detection of ligands exhibiting incipient cannabinoid receptor type 2 (CB2R) subtype selectivity and highlights the significant neurotoxicity of representative SCRAs on mouse primary neuronal cells. Several of the new emerging SCRAs are currently expected to have a rather limited potential for harm, as the evaluation of their pharmacological profiles revealed lower potencies and/or efficacies. Conceived as a resource to foster collaborative investigation of the physiological effects of SCRAs, the library obtained can contribute to addressing the challenge posed by recreational designer drugs.
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Exploring the Effect of Halogenation in a Series of Potent and Selective A 2B Adenosine Receptor Antagonists. J Med Chem 2022; 66:890-912. [PMID: 36517209 PMCID: PMC9841532 DOI: 10.1021/acs.jmedchem.2c01768] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The modulation of the A2B adenosine receptor is a promising strategy in cancer (immuno) therapy, with A2BAR antagonists emerging as immune checkpoint inhibitors. Herein, we report a systematic assessment of the impact of (di- and mono-)halogenation at positions 7 and/or 8 on both A2BAR affinity and pharmacokinetic properties of a collection of A2BAR antagonists and its study with structure-based free energy perturbation simulations. Monohalogenation at position 8 produced potent A2BAR ligands irrespective of the nature of the halogen. In contrast, halogenation at position 7 and dihalogenation produced a halogen-size-dependent decay in affinity. Eight novel A2BAR ligands exhibited remarkable affinity (Ki < 10 nM), exquisite subtype selectivity, and enantioselective recognition, with some eutomers eliciting sub-nanomolar affinity. The pharmacokinetic profile of representative derivatives showed enhanced solubility and microsomal stability. Finally, two compounds showed the capacity of reversing the antiproliferative effect of adenosine in activated primary human peripheral blood mononuclear cells.
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A 2B adenosine receptor antagonists rescue lymphocyte activity in adenosine-producing patient-derived cancer models. J Immunother Cancer 2022; 10:e004592. [PMID: 35580926 PMCID: PMC9115112 DOI: 10.1136/jitc-2022-004592] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/26/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Adenosine is a metabolite that suppresses antitumor immune response of T and NK cells via extracellular binding to the two subtypes of adenosine-2 receptors, A2ARs. While blockade of the A2AARs subtype effectively rescues lymphocyte activity, with four A2AAR antagonists currently in anticancer clinical trials, less is known for the therapeutic potential of the other A2BAR blockade within cancer immunotherapy. Recent studies suggest the formation of A2AAR/A2BAR dimers in tissues that coexpress the two receptor subtypes, where the A2BAR plays a dominant role, suggesting it as a promising target for cancer immunotherapy. METHODS We report the synthesis and functional evaluation of five potent A2BAR antagonists and a dual A2AAR/A2BAR antagonist. The compounds were designed using previous pharmacological data assisted by modeling studies. Synthesis was developed using multicomponent approaches. Flow cytometry was used to evaluate the phenotype of T and NK cells on A2BAR antagonist treatment. Functional activity of T and NK cells was tested in patient-derived tumor spheroid models. RESULTS We provide data for six novel small molecules: five A2BAR selective antagonists and a dual A2AAR/A2BAR antagonist. The growth of patient-derived breast cancer spheroids is prevented when treated with A2BAR antagonists. To elucidate if this depends on increased lymphocyte activity, immune cells proliferation, and cytokine production, lymphocyte infiltration was evaluated and compared with the potent A2AAR antagonist AZD-4635. We find that A2BAR antagonists rescue T and NK cell proliferation, IFNγ and perforin production, and increase tumor infiltrating lymphocytes infiltration into tumor spheroids without altering the expression of adhesion molecules. CONCLUSIONS Our results demonstrate that A2BAR is a promising target in immunotherapy, identifying ISAM-R56A as the most potent candidate for A2BAR blockade. Inhibition of A2BAR signaling restores T cell function and proliferation. Furthermore, A2BAR and dual A2AAR/A2BAR antagonists showed similar or better results than A2AAR antagonist AZD-4635 reinforcing the idea of dominant role of the A2BAR in the regulation of the immune system.
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Exploring Non-orthosteric Interactions with a Series of Potent and Selective A 3 Antagonists. ACS Med Chem Lett 2022; 13:243-249. [PMID: 35178181 PMCID: PMC8842279 DOI: 10.1021/acsmedchemlett.1c00598] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 01/06/2022] [Indexed: 12/18/2022] Open
Abstract
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A library of potent
and highly A3AR selective pyrimidine-based
compounds was designed to explore non-orthosteric interactions within
this receptor. Starting from a prototypical orthosteric A3AR antagonist (ISVY130), the structure-based design explored functionalized
residues at the exocyclic amide L1 region and aimed to provide additional
interactions outside the A3AR orthosteric site. The novel
ligands were assembled through an efficient and succinct synthetic
approach, resulting in compounds that retain the A3AR potent
and selective profile while improving the solubility of the original
scaffold. The experimentally demonstrated tolerability of the L1 region
to structural functionalization was further assessed by molecular
dynamics simulations, giving hints of the non-orthosteric interactions
explored by these series. The results pave the way to explore newly
functionalized A3AR ligands, including covalent drugs and
molecular probes for diagnostic and delivery purposes.
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Optimization of 2-Amino-4,6-diarylpyrimidine-5-carbonitriles as Potent and Selective A1 Antagonists. J Med Chem 2022; 65:2091-2106. [PMID: 35068155 PMCID: PMC8842224 DOI: 10.1021/acs.jmedchem.1c01636] [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] [Indexed: 11/29/2022]
Abstract
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We herein document a large collection
of 108 2-amino-4,6-disubstituted-pyrimidine
derivatives as potent, structurally simple, and highly selective A1AR ligands. The most attractive ligands were confirmed as
antagonists of the canonical cyclic adenosine monophosphate pathway,
and some pharmacokinetic parameters were preliminarilly evaluated.
The library, built through a reliable and efficient three-component
reaction, comprehensively explored the chemical space allowing the
identification of the most prominent features of the structure–activity
and structure–selectivity relationships around this scaffold.
These included the influence on the selectivity profile of the aromatic
residues at positions R4 and R6 of the pyrimidine
core but most importantly the prominent role to the unprecedented
A1AR selectivity profile exerted by the methyl group introduced
at the exocyclic amino group. The structure–activity relationship
trends on both A1 and A2AARs were conveniently
interpreted with rigorous free energy perturbation simulations, which
started from the receptor-driven docking model that guided the design
of these series.
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Potent and Subtype-Selective Dopamine D 2 Receptor Biased Partial Agonists Discovered via an Ugi-Based Approach. J Med Chem 2021; 64:8710-8726. [PMID: 34110150 PMCID: PMC8552448 DOI: 10.1021/acs.jmedchem.1c00704] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
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Using
a previously unexplored, efficient, and versatile multicomponent
method, we herein report the rapid generation of novel potent and
subtype-selective DRD2 biased partial agonists. This strategy
exemplifies the search for diverse and previously unexplored moieties
for the secondary/allosteric pharmacophore of the common phenyl-piperazine
scaffold. The pharmacological characterization of the new compound
series led to the identification of several ligands with excellent
DRD2 affinity and subtype selectivity and remarkable functional
selectivity for either the cAMP (22a and 24d) or the β-arrestin (27a and 29c)
signaling pathways. These results were further interpreted on the
basis of molecular models of these ligands in complex with the recent
DRD2 crystal structures, highlighting the critical role
of the secondary/allosteric pharmacophore in modulating the functional
selectivity profile.
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9
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3,4-Dihydropyrimidin-2(1 H)-ones as Antagonists of the Human A 2B Adenosine Receptor: Optimization, Structure-Activity Relationship Studies, and Enantiospecific Recognition. J Med Chem 2020; 64:458-480. [PMID: 33372800 DOI: 10.1021/acs.jmedchem.0c01431] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
We present and thoroughly characterize a large collection of 3,4-dihydropyrimidin-2(1H)-ones as A2BAR antagonists, an emerging strategy in cancer (immuno) therapy. Most compounds selectively bind A2BAR, with a number of potent and selective antagonists further confirmed by functional cyclic adenosine monophosphate experiments. The series was analyzed with one of the most exhaustive free energy perturbation studies on a GPCR, obtaining an accurate model of the structure-activity relationship of this chemotype. The stereospecific binding modeled for this scaffold was confirmed by resolving the two most potent ligands [(±)-47, and (±)-38 Ki = 10.20 and 23.6 nM, respectively] into their two enantiomers, isolating the affinity on the corresponding (S)-eutomers (Ki = 6.30 and 11.10 nM, respectively). The assessment of the effect in representative cytochromes (CYP3A4 and CYP2D6) demonstrated insignificant inhibitory activity, while in vitro experiments in three prostate cancer cells demonstrated that this pair of compounds exhibits a pronounced antimetastatic effect.
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X-Ray Crystallography and Free Energy Calculations Reveal the Binding Mechanism of A 2A Adenosine Receptor Antagonists. Angew Chem Int Ed Engl 2020; 59:16536-16543. [PMID: 32542862 PMCID: PMC7540567 DOI: 10.1002/anie.202003788] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 05/18/2020] [Indexed: 01/04/2023]
Abstract
We present a robust protocol based on iterations of free energy perturbation (FEP) calculations, chemical synthesis, biophysical mapping and X-ray crystallography to reveal the binding mode of an antagonist series to the A2A adenosine receptor (AR). Eight A2A AR binding site mutations from biophysical mapping experiments were initially analyzed with sidechain FEP simulations, performed on alternate binding modes. The results distinctively supported one binding mode, which was subsequently used to design new chromone derivatives. Their affinities for the A2A AR were experimentally determined and investigated through a cycle of ligand-FEP calculations, validating the binding orientation of the different chemical substituents proposed. Subsequent X-ray crystallography of the A2A AR with a low and a high affinity chromone derivative confirmed the predicted binding orientation. The new molecules and structures here reported were driven by free energy calculations, and provide new insights on antagonist binding to the A2A AR, an emerging target in immuno-oncology.
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11
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X‐Ray Crystallography and Free Energy Calculations Reveal the Binding Mechanism of A
2A
Adenosine Receptor Antagonists. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202003788] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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12
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Nitrogen-Walk Approach to Explore Bioisosteric Replacements in a Series of Potent A 2B Adenosine Receptor Antagonists. J Med Chem 2020; 63:7721-7739. [PMID: 32573250 DOI: 10.1021/acs.jmedchem.0c00564] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A systematic exploration of bioisosteric replacements for furan and thiophene cores in a series of potent A2BAR antagonists has been carried out using the nitrogen-walk approach. A collection of 42 novel alkyl 4-substituted-2-methyl-1,4-dihydrobenzo[4,5]imidazo[1,2-a]pyrimidine-3-carboxylates, which contain 18 different pentagonal heterocyclic frameworks at position 4, was synthesized and evaluated. This study enabled the identification of new ligands that combine remarkable affinity (Ki < 30 nM) and exquisite selectivity. The structure-activity relationship (SAR) trends identified were substantiated by a molecular modeling study, based on a receptor-driven docking model and including a systematic free energy perturbation (FEP) study. Preliminary evaluation of the CYP3A4 and CYP2D6 inhibitory activity in optimized ligands evidenced weak and negligible activity, respectively. The stereospecific interaction between hA2BAR and the eutomer of the most attractive novel antagonist (S)-18g (Ki = 3.66 nM) was validated.
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13
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Trifluorinated Pyrimidine-Based A2B Antagonists: Optimization and Evidence of Stereospecific Recognition. J Med Chem 2019; 62:9315-9330. [DOI: 10.1021/acs.jmedchem.9b01340] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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14
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Clinical validation of blood/brain glutamate grabbing in acute ischemic stroke. Ann Neurol 2018; 84:260-273. [DOI: 10.1002/ana.25286] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 06/29/2018] [Accepted: 06/29/2018] [Indexed: 01/28/2023]
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15
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Computer-aided design of multi-target ligands at A 1R, A 2AR and PDE10A, key proteins in neurodegenerative diseases. J Cheminform 2017; 9:67. [PMID: 29290010 PMCID: PMC5748027 DOI: 10.1186/s13321-017-0249-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 12/01/2017] [Indexed: 01/30/2023] Open
Abstract
Compounds designed to display polypharmacology may have utility in treating complex diseases, where activity at multiple targets is required to produce a clinical effect. In particular, suitable compounds may be useful in treating neurodegenerative diseases by promoting neuronal survival in a synergistic manner via their multi-target activity at the adenosine A1 and A2A receptors (A1R and A2AR) and phosphodiesterase 10A (PDE10A), which modulate intracellular cAMP levels. Hence, in this work we describe a computational method for the design of synthetically feasible ligands that bind to A1 and A2A receptors and inhibit phosphodiesterase 10A (PDE10A), involving a retrosynthetic approach employing in silico target prediction and docking, which may be generally applicable to multi-target compound design at several target classes. This approach has identified 2-aminopyridine-3-carbonitriles as the first multi-target ligands at A1R, A2AR and PDE10A, by showing agreement between the ligand and structure based predictions at these targets. The series were synthesized via an efficient one-pot scheme and validated pharmacologically as A1R/A2AR-PDE10A ligands, with IC50 values of 2.4-10.0 μM at PDE10A and Ki values of 34-294 nM at A1R and/or A2AR. Furthermore, selectivity profiling of the synthesized 2-amino-pyridin-3-carbonitriles against other subtypes of both protein families showed that the multi-target ligand 8 exhibited a minimum of twofold selectivity over all tested off-targets. In addition, both compounds 8 and 16 exhibited the desired multi-target profile, which could be considered for further functional efficacy assessment, analog modification for the improvement of selectivity towards A1R, A2AR and PDE10A collectively, and evaluation of their potential synergy in modulating cAMP levels.
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16
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Development of Fluorescent Probes that Target Serotonin 5-HT 2B Receptors. Sci Rep 2017; 7:10765. [PMID: 28883627 PMCID: PMC5589878 DOI: 10.1038/s41598-017-11370-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 08/23/2017] [Indexed: 01/07/2023] Open
Abstract
Some 5-HT2B fluorescent probes were obtained by tagging 1-(2,5-dimethoxy-4-iodophenyl)-propan-2-amine (DOI) with a subset of fluorescent amines. Some of the resulting fluorescent ligands showed excellent affinity and selectivity profiles at the 5-HT2B receptors (e.g. 12b), while retain the agonistic functional behaviour of the model ligand (DOI). The study highlighted the most salient features of the structure-activity relationship in this series and these were substantiated by a molecular modelling study based on a receptor-driven docking model constructed on the basis of the crystal structure of the human 5-HT2B receptor. One of the fluorescent ligands developed in this work, compound 12i, specifically labelled CHO-K1 cells expressing 5-HT2B receptors and not parental CHO-K1 cells in a concentration-dependent manner. 12i enables imaging and quantification of specific 5-HT2B receptor labelling in live cells by automated fluorescence microscopy as well as quantification by measurements of fluorescence intensity using a fluorescence plate reader.
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17
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Effect of Nitrogen Atom Substitution in A3 Adenosine Receptor Binding: N-(4,6-Diarylpyridin-2-yl)acetamides as Potent and Selective Antagonists. J Med Chem 2017; 60:7502-7511. [DOI: 10.1021/acs.jmedchem.7b00860] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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18
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Enantiospecific Recognition at the A2B Adenosine Receptor by Alkyl 2-Cyanoimino-4-substituted-6-methyl-1,2,3,4-tetrahydropyrimidine-5-carboxylates. J Med Chem 2017; 60:3372-3382. [DOI: 10.1021/acs.jmedchem.7b00138] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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19
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Drug structural features affect drug delivery from hyperbranched polyesteramide hot melt extrudates. Eur J Pharm Biopharm 2016; 102:1-8. [PMID: 26912462 DOI: 10.1016/j.ejpb.2016.02.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 01/08/2016] [Accepted: 02/14/2016] [Indexed: 11/27/2022]
Abstract
The aim of this study was firstly to evaluate the utility of Hybrane S1200 as a hot melt extrusion (HME) carrier to prepare instant-release multiparticulate systems for very poorly-soluble drugs such as ketoconazole or nifedipine. Hybrane S1200 allows an easy extrusion of its drug mixtures at a relatively low temperature, not higher than 90°C, and with no need of any additional aid. Extrudates containing 10% of nifedipine or ketoconazole form monophasic systems. Nifedipine extrudate shows no drug release in drug dissolution rate tests while ketoconazole extrudate release reaches only 60% of drug content. Additionally, a turbidity in the dissolution medium due to the formation of a kind of polymer vesicles (ranging 3-0.2μm in size) is observed. These facts could suggest a chemical interaction between the polymer and both drugs, triggered by the HME process. Both nifedipine and ketoconazole share characteristic acid-base profiles that could facilitate a degradation processes within the polymer, thus modifying Hybrane's water-solubility and polar nature. Such modified polymer structure, when in aqueous medium, forms the aforementioned stable vesicles that may encapsulate the drugs, thus making its delivery difficult or even preventing it.
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Discovery of Potent and Highly Selective A2B Adenosine Receptor Antagonist Chemotypes. J Med Chem 2016; 59:1967-83. [DOI: 10.1021/acs.jmedchem.5b01586] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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21
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22
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Integrated Ugi-Based Assembly of Functionally, Skeletally, and Stereochemically Diverse 1,4-Benzodiazepin-2-ones. J Org Chem 2015; 80:1533-49. [DOI: 10.1021/jo502382q] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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23
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Abstract
An expedient and concise Ugi-based unified approach for the rapid assembly of quinoxaline frameworks has been developed. This convergent and versatile method uses readily available commercial reagents, does not require advanced intermediates, and exhibits excellent bond-forming efficiency, thus exemplifying the operationally simple synthesis of quinoxaline libraries.
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24
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Structure-Based Design of New KSP-Eg5 Inhibitors Assisted by a Targeted Multicomponent Reaction. Chembiochem 2014; 15:1471-80. [DOI: 10.1002/cbic.201402089] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Indexed: 11/06/2022]
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25
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Discovery of 3,4-Dihydropyrimidin-2(1H)-ones As a Novel Class of Potent and Selective A2B Adenosine Receptor Antagonists. ACS Med Chem Lett 2013; 4:1031-6. [PMID: 24900602 PMCID: PMC4027370 DOI: 10.1021/ml400185v] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 10/03/2013] [Indexed: 01/18/2023] Open
Abstract
We describe the discovery and optimization of 3,4-dihydropyrimidin-2(1H)-ones as a novel family of (nonxanthine) A2B receptor antagonists that exhibit an unusually high selectivity profile. The Biginelli-based hit optimization process enabled a thoughtful exploration of the structure-activity and structure-selectivity relationships for this chemotype, enabling the identification of ligands that combine structural simplicity with excellent hA2B AdoR affinity and remarkable selectivity profiles.
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26
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Three-component assembly of structurally diverse 2-aminopyrimidine-5-carbonitriles. ACS COMBINATORIAL SCIENCE 2013; 15:370-8. [PMID: 23697392 DOI: 10.1021/co4000503] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An expedient route for the synthesis of libraries of diversely decorated 2-aminopyrimidine-5-carbonitriles is reported. This approach is based on a three-component reaction followed by spontaneous aromatization.
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27
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Copper-catalyzed Huisgen 1,3-dipolar cycloaddition under oxidative conditions: polymer-assisted assembly of 4-acyl-1-substituted-1,2,3-triazoles. J Org Chem 2013; 78:6540-9. [PMID: 23738944 DOI: 10.1021/jo400800j] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We herein document the first example of a reliable copper-catalyzed Huisgen 1,3-dipolar cycloaddition under oxidative conditions. The combined use of two polymer-supported reagents (polystyrene-1,5,7-triazabicyclo[4,4,0]dec-5-ene/Cu and polystyrene-2-iodoxybenzamide) overcomes the thermodynamic instability of copper(I) species toward oxidation, enabling the reliable Cu-catalyzed Huisgen 1,3-dipolar cycloadditions in the presence of an oxidant agent. This polymer-assisted pathway, not feasible under conventional homogeneous conditions, provides a direct assembly of 4-acyl-1-substituted-1,2,3-triazoles, contributing to expand the reliability and scope of Cu(I)-catalyzed alkyne-azide cycloaddition.
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28
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29
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Discovery and preliminary SAR of 5-arylidene-2,2-dimethyl-1,3-dioxane- 4,6-diones as platelet aggregation inhibitors. Comb Chem High Throughput Screen 2012; 15:551-4. [PMID: 22272691 DOI: 10.2174/138620712801619122] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 01/18/2012] [Accepted: 02/10/2012] [Indexed: 11/22/2022]
Abstract
We herein document the discovery of 5-arylidene-2,2-dimethyl-1,3-dioxane-4,6-diones as a novel family of platelet aggregation inhibitors. The preliminary optimization study enabled us to establish the most salient features of the structure-activity relationships in this series as well as to identify novel derivatives that are upto 60 times more potent than the hit structure 1 and slightly superior to the reference drug Milrinone.
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30
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Supported p-toluenesulfonic acid as a highly robust and eco-friendly isocyanide scavenger. ACS COMBINATORIAL SCIENCE 2011; 13:89-95. [PMID: 21247131 DOI: 10.1021/co100035z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We document here the use of polymer-supported p-toluenesulfonic acid as a highly effective, robust, economical and eco-friendly isocyanide scavenger. The herein described strategy circumvent the intense and repulsive odor of volatile isocyanides, enabling simplified and odorless workup and purifications. The usefulness of the new scavengers has been validated in a set of diverse isocyanide-based organic transformations and this approach is also amenable to parallel synthesis techniques.
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Silica-supported aluminum chloride-assisted solution phase synthesis of pyridazinone-based antiplatelet agents. ACS COMBINATORIAL SCIENCE 2011; 13:7-12. [PMID: 21247118 DOI: 10.1021/co100017h] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A solution phase protocol that enabled the synthesis of three diverse libraries of pyridazin-3-ones incorporating α,β-unsaturated moieties at position 5 of the heterocyclic core has been developed using silica-supported aluminum trichloride as a heterogeneous and reusable catalyst. This robust procedure has facilitated the hit to lead process for these series of compounds and allowed the identification of new potent derivatives that elicit antiplatelet activity in the low micromolar range.
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