1
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Schiavone DV, Gallardo J, Kapkayeva DM, Baucom JC, Murelli RP. Lactam-fused tropolones: a new tunable, environmentally sensitive fluorophore class. Org Biomol Chem 2023; 21:7900-7907. [PMID: 37750360 DOI: 10.1039/d3ob01263h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Abstract
Fluorescent small-molecules capable of altering their profiles in response to environmental changes are exceptionally valuable tool compounds throughout the scientific community. The following manuscriipt describes a new class of fluorescent small molecules based on lactam-fused tropolones that are responsive to a dynamic range of environmental changes. These molecules can be easily obtained through a rapid annulation procedure between appropriately functionalized tropolones and primary amines, which is often complete within minutes at room temperature. Molecules generated through this approach have been identified with fluoresence emission across the visible light spectra, and can be tuned based on either the tropolone or amine component. They are also highly responsive to changes in solvent, pH, and certain divalent metal ions. Tropolone-fused lactams thus represent a new class of tunable fluorescent small molecules that could find value throughout the scientific community.
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Affiliation(s)
- Daniel V Schiavone
- Department of Chemistry and Biochemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA.
- PhD Program in Chemistry, The Graduate Center, The City University of New York, New York, NY, USA
| | - Joel Gallardo
- Department of Chemistry and Biochemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA.
- PhD Program in Chemistry, The Graduate Center, The City University of New York, New York, NY, USA
| | - Diana M Kapkayeva
- Department of Chemistry and Biochemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA.
| | - John-Charles Baucom
- Department of Chemistry and Biochemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA.
- PhD Program in Chemistry, The Graduate Center, The City University of New York, New York, NY, USA
| | - Ryan P Murelli
- Department of Chemistry and Biochemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA.
- PhD Program in Chemistry, The Graduate Center, The City University of New York, New York, NY, USA
- PhD Program in Biochemistry, The Graduate Center, The City University of New York, New York, NY, USA
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2
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Gazquez Casals A, Berkowitz AJ, Yu AJ, Waters HE, Schiavone DV, Kapkayeva DM, Morrison LA, Murelli RP. Antiviral activity of amide-appended α-hydroxytropolones against herpes simplex virus-1 and -2. RSC Adv 2023; 13:8743-8752. [PMID: 36936842 PMCID: PMC10016935 DOI: 10.1039/d2ra06749h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 02/28/2023] [Indexed: 03/17/2023] Open
Abstract
α-Hydroxytropolones (αHTs) have potent antiviral activity against herpes simplex virus-1 and -2 (HSV-1 and HSV-2) in cell culture, including against acyclovir-resistant mutants, and as a result have the potential to be developed as antiviral drugs targeting these viruses. We recently described a convenient final-step amidation strategy to their synthesis, and this was used to generate 57 amide-substituted αHTs that were tested against hepatitis B virus. The following manuscript describes the evaluation of this library against HSV-1, as well as a subset against HSV-2. The structure-function analysis obtained from these studies demonstrates the importance of lipophilicity and rigidity to αHT-based anti-HSV potency, consistent with our prior work on smaller libraries. We used this information to synthesize and test a targeted library of 4 additional amide-appended αHTs. The most potent of this new series had a 50% effective concentration (EC50) for viral inhibition of 72 nM, on par with the most potent αHT antivirals we have found to date. Given the ease of synthesis of amide-appended αHTs, this new class of antiviral compounds and the chemistry to make them should be highly valuable in future anti-HSV drug development.
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Affiliation(s)
- Andreu Gazquez Casals
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine St. Louis MO USA
| | - Alex J Berkowitz
- Department of Chemistry, Brooklyn College, The City University of New York Brooklyn NY USA
- PhD Program in Chemistry, The Graduate Center, The City University of New York New York NY USA
| | - Alice J Yu
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine St. Louis MO USA
| | - Hope E Waters
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine St. Louis MO USA
| | - Daniel V Schiavone
- Department of Chemistry, Brooklyn College, The City University of New York Brooklyn NY USA
- PhD Program in Chemistry, The Graduate Center, The City University of New York New York NY USA
| | - Diana M Kapkayeva
- Department of Chemistry, Brooklyn College, The City University of New York Brooklyn NY USA
| | - Lynda A Morrison
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine St. Louis MO USA
| | - Ryan P Murelli
- Department of Chemistry, Brooklyn College, The City University of New York Brooklyn NY USA
- PhD Program in Chemistry, The Graduate Center, The City University of New York New York NY USA
- PhD Program in Biochemistry, The Graduate Center, The City University of New York New York NY USA
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3
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Murelli RP, Berkowitz AJ, Zuschlag DW. Carbocycloaddition Strategies for Troponoid Synthesis. Tetrahedron 2023; 130:133175. [PMID: 36777111 PMCID: PMC9910567 DOI: 10.1016/j.tet.2022.133175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Tropone is the prototypical aromatic 7-membered ring, and can be found in virtually any undergraduate textbook as a key example of non-benzenoid aromaticity. Aside from this important historical role, tropone is also of high interest as a uniquely reactive synthon in complex chemical synthesis as well as a valuable chemotype in drug design. More recently, there has been growing interest in the utility of tropones for catalysis and material science. Thus, synthetic strategies capable of synthesizing functional tropones are key to fully exploiting the potential of this aromatic ring system. Cycloaddition reactions are particularly powerful methods for constructing carbocycles, and these strategies in turn have proven to be powerful for generating troponoids. The following review article provides an overview of strategies for troponoids wherein the 7-membered carbocycle is generated through a cycloaddition reaction. Representative examples of each strategy are also provided.
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Affiliation(s)
- Ryan P Murelli
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, NY, 11210, United States
- Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, 10016, United States
- Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY, 10016, United States
| | - Alex J Berkowitz
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, NY, 11210, United States
- Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, 10016, United States
| | - Daniel W Zuschlag
- Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, 10016, United States
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4
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Geerling E, Murphy V, Mai MC, Stone ET, Casals AG, Hassert M, O’Dea AT, Cao F, Donlin MJ, Elagawany M, Elgendy B, Pardali V, Giannakopoulou E, Zoidis G, Schiavone DV, Berkowitz AJ, Agyemang NB, Murelli RP, Tavis JE, Pinto AK, Brien JD. Metal coordinating inhibitors of Rift Valley fever virus replication. PLoS One 2022; 17:e0274266. [PMID: 36112605 PMCID: PMC9481026 DOI: 10.1371/journal.pone.0274266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 08/24/2022] [Indexed: 11/18/2022] Open
Abstract
Rift Valley fever virus (RVFV) is a veterinary and human pathogen and is an agent of bioterrorism concern. Currently, RVFV treatment is limited to supportive care, so new drugs to control RVFV infection are urgently needed. RVFV is a member of the order Bunyavirales, whose replication depends on the enzymatic activity of the viral L protein. Screening for RVFV inhibitors among compounds with divalent cation-coordinating motifs similar to known viral nuclease inhibitors identified 47 novel RVFV inhibitors with selective indexes from 1.1–103 and 50% effective concentrations of 1.2–56 μM in Vero cells, primarily α-Hydroxytropolones and N-Hydroxypyridinediones. Inhibitor activity and selective index was validated in the human cell line A549. To evaluate specificity, select compounds were tested against a second Bunyavirus, La Crosse Virus (LACV), and the flavivirus Zika (ZIKV). These data indicate that the α-Hydroxytropolone and N-Hydroxypyridinedione chemotypes should be investigated in the future to determine their mechanism(s) of action allowing further development as therapeutics for RVFV and LACV, and these chemotypes should be evaluated for activity against related pathogens, including Hantaan virus, severe fever with thrombocytopenia syndrome virus, Crimean-Congo hemorrhagic fever virus.
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Affiliation(s)
- Elizabeth Geerling
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Valerie Murphy
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Maria C. Mai
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - E. Taylor Stone
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Andreu Gazquez Casals
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Mariah Hassert
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Austin T. O’Dea
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Feng Cao
- John Cochran Division, Department of Veterans Affairs Medical Center, Saint Louis, Missouri, United States of America
| | - Maureen J. Donlin
- Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Mohamed Elagawany
- Center for Clinical Pharmacology, Washington University School of Medicine and University of Health Sciences and Pharmacy, Saint Louis, Missouri, United States of America
| | - Bahaa Elgendy
- Center for Clinical Pharmacology, Washington University School of Medicine and University of Health Sciences and Pharmacy, Saint Louis, Missouri, United States of America
- Department of Pharmaceutical and Administrative Sciences, University of Health Sciences and Pharmacy, Saint Louis, Missouri, United States of America
| | - Vasiliki Pardali
- Division of Pharmaceutical Chemistry, Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Athens, Greece
| | - Erofili Giannakopoulou
- Division of Pharmaceutical Chemistry, Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Athens, Greece
| | - Grigoris Zoidis
- Division of Pharmaceutical Chemistry, Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Athens, Greece
| | - Daniel V. Schiavone
- Department of Chemistry and The Graduate Center of The City University of New York, Brooklyn College, The City University of New York, Brooklyn, New York, United States of America
| | - Alex J. Berkowitz
- Department of Chemistry and The Graduate Center of The City University of New York, Brooklyn College, The City University of New York, Brooklyn, New York, United States of America
| | - Nana B. Agyemang
- Department of Chemistry and The Graduate Center of The City University of New York, Brooklyn College, The City University of New York, Brooklyn, New York, United States of America
| | - Ryan P. Murelli
- Department of Chemistry and The Graduate Center of The City University of New York, Brooklyn College, The City University of New York, Brooklyn, New York, United States of America
| | - John E. Tavis
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Amelia K. Pinto
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - James D. Brien
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
- * E-mail:
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5
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Synthesis of Substituted Tropones and Advancement for the Construction of Structurally Significant Skeletons. ChemistrySelect 2022. [DOI: 10.1002/slct.202200440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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6
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Schiavone DV, Kapkayeva DM, Li Q, Woodson ME, Casals AG, Morrison LA, Tavis JE, Murelli RP. Synthesis of Polyoxygenated Tropolones and their Antiviral Activity against Hepatitis B Virus and Herpes Simplex Virus-1. Chemistry 2022; 28:e202104112. [PMID: 34984767 PMCID: PMC8858858 DOI: 10.1002/chem.202104112] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Indexed: 11/06/2022]
Abstract
Polyoxygenated tropolones possess a broad range of biological activity, and as a result are promising lead structures or fragments for drug development. However, structure-function studies and subsequent optimization have been challenging, in part due to the limited number of readily available tropolones and the obstacles to their synthesis. Oxidopyrylium [5+2] cycloaddition can effectively generate a diverse array of seven-membered ring carbocycles, and as a result can provide a highly general strategy for tropolone synthesis. Here, we describe the use of 3-hydroxy-4-pyrone-based oxidopyrylium cycloaddition chemistry in the synthesis of functionalized 3,7-dimethoxytropolones, 3,7-dihydroxytropolones, and isomeric 3-hydroxy-7-methoxytropolones through complementary benzyl alcohol-incorporating procedures. The antiviral activity of these molecules against herpes simplex virus-1 and hepatitis B virus is also described, highlighting the value of this approach and providing new structure-function insights relevant to their antiviral activity.
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Affiliation(s)
- Daniel V. Schiavone
- Department of Chemistry, Brooklyn College of the City University of New York, Brooklyn, New York 11210, USA,PhD Program in Chemistry, The Graduate Center of the City University of New York, New York, New York 10016, USA
| | - Diana M. Kapkayeva
- Department of Chemistry, Brooklyn College of the City University of New York, Brooklyn, New York 11210, USA
| | - Qilan Li
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, USA
| | - Molly E. Woodson
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, USA
| | - Andreu Gazquez Casals
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, USA
| | - Lynda A. Morrison
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, USA
| | - John E. Tavis
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, USA
| | - Ryan P. Murelli
- Department of Chemistry, Brooklyn College of the City University of New York, Brooklyn, New York 11210, USA,PhD Program in Chemistry, The Graduate Center of the City University of New York, New York, New York 10016, USA
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7
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Berkowitz AJ, Murelli RP. Synthesis of α-Tropolones through Autoxidation of Dioxole-Fused Cycloheptatrienes. J Org Chem 2022; 87:4499-4507. [PMID: 35007070 PMCID: PMC9002940 DOI: 10.1021/acs.joc.1c02713] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Herein, we describe the formation of tropolones through the autoxidation of Büchner reaction-derived cycloheptatrienes. The reaction is exceptionally simple procedurally, as it involves blowing a stream of compressed air over the cycloheptatriene, and the products can be obtained without any need for chromatography. The chemistry works specifically on dioxolane-fused systems or close variants, and substitution patterns are also important. A radical-based mechanistic hypothesis is put forward to explain these results. Finally, we demonstrate the utility of the overall process in the synthesis of amide-appended tropolones and an isomer of stipitatic acid.
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Affiliation(s)
- Alex J Berkowitz
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York 11210, United States.,Ph.D. Program in Chemistry, The Graduate Center of The City University of New York, New York, New York 10016, United States
| | - Ryan P Murelli
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York 11210, United States.,Ph.D. Program in Chemistry, The Graduate Center of The City University of New York, New York, New York 10016, United States.,Ph.D. Program in Biochemistry, The Graduate Center of The City University of New York, New York, New York 10016, United States
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8
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Efficient Inhibition of Hepatitis B Virus (HBV) Replication and cccDNA Formation by HBV Ribonuclease H Inhibitors during Infection. Antimicrob Agents Chemother 2021; 65:e0146021. [PMID: 34516242 DOI: 10.1128/aac.01460-21] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The hepatitis B virus (HBV) ribonuclease H (RNase H) is an attractive but unexploited drug target. Here, we addressed three limitations to the current state of RNase H inhibitor development: (a) Efficacy has been assessed only in transfected cell lines. (b) Cytotoxicity data are from transformed cell lines rather than primary cells. (c) It is unknown how the compounds work against nucleos(t)ide analog resistant HBV strains. Three RNase H inhibitors from different chemotypes, 110 (α-hydroxytropolone), 1133 (N-hydroxypyridinedione), and 1073 (N-hydroxynapthyridinone), were tested in HBV-infected HepG2-NTCP cells for inhibition of cccDNA accumulation and HBV product formation. 50% effective concentrations (EC50s) were 0.049-0.078 μM in the infection studies compared to 0.29-1.6 μM in transfected cells. All compounds suppressed cccDNA formation by >98% at 5 μM when added shortly after infection. HBV RNA, intracellular and extracellular DNA, and HBsAg secretion were all robustly suppressed. The greater efficacy of the inhibitors when added shortly after infection is presumably due to blocking amplification of the HBV cccDNA, which suppresses events downstream of cccDNA formation. The compounds had 50% cytotoxic concentrations (CC50s) of 16-100 μM in HepG2-derived cell lines but were nontoxic in primary human hepatocytes, possibly due to the quiescent state of the hepatocytes. The compounds had similar EC50s against replication of wild-type, lamivudine-resistant, and adefovir/lamivudine-resistant HBV, as expected because the RNase H inhibitors do not target the viral reverse transcriptase active site. These studies expand confidence in inhibiting the HBV RNase H as a drug strategy and support inclusion of RNase H inhibitors in novel curative drug combinations for HBV.
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9
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Schiavone DV, Kapkayeva DM, Murelli RP. Investigations into a Stoichiometrically Equivalent Intermolecular Oxidopyrylium [5 + 2] Cycloaddition Reaction Leveraging 3-Hydroxy-4-pyrone-Based Oxidopyrylium Dimers. J Org Chem 2021; 86:3826-3835. [PMID: 33586990 PMCID: PMC8061303 DOI: 10.1021/acs.joc.0c02655] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Oxidopyrylium [5 + 2] cycloaddition reactions are powerful strategies for constructing complex bicyclic architectures. However, intermolecular cycloadditions of oxidopyrylium ylides are limited due to competing dimerization processes; consequently, high equivalents of dipolarophiles are often used to help intercept the ylide prior to dimerization. Recent studies by our lab have revealed that oxidopyrylium dimers derived from 3-hydroxy-4-pyrones are capable of reverting back to ylides in situ and as a result can be used as clean oxidopyrylium ylide sources. The following manuscript investigates intermolecular cycloaddition reactions between 3-hydroxy-4-pyrone-derived oxidopyrylium dimers and stoichiometrically equivalent ratios of alkyne dipolarophiles under thermal conditions. With certain reactive alkynes, pure cycloadducts can be obtained following a simple evaporation of the solvent, which is a benefit of the completely atom-economical reaction conditions. However, when less reactive alkynes are used the yields suffer due to a competing dimer rearrangement. Finally, when reactive-yet-volatile alkynes are used, such as methyl propiolate, competing 2:1 ylide/alkyne cycloadducts are observed. Intriguingly, these complex cycloadducts, which can be obtained in good yields from the pure cycloadducts, form with high regio- and stereoselectivities; however, both the regio-and stereoselectivities differ remarkably based on the source of the oxidopyrylium ylide.
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Affiliation(s)
- Daniel V. Schiavone
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, NY, USA
- PhD Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, USA
| | - Diana M. Kapkayeva
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, NY, USA
| | - Ryan P. Murelli
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, NY, USA
- PhD Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, USA
- PhD Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY, USA
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10
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Du Y, Huang B, Zeng J, Cai M. Recyclable heterogeneous gold(I)-catalyzed oxidative ring expansion of alkynyl quinols: a practical access to tropone and its analogues. Dalton Trans 2021; 50:6488-6499. [PMID: 33903864 DOI: 10.1039/d1dt00988e] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The heterogeneous gold(i)-catalyzed oxidative ring expansion of alkynyl quinols has been achieved by using a benzyldiphenylphosphine-modified MCM-41-immobilized gold(i) complex [MCM-41-BnPh2P-AuNTf2] as the catalyst and 8-methylquinoline N-oxide as the oxidant under mild reaction conditions, yielding a variety of functionalized tropone derivatives in good to excellent yields. Extension of this methodology allows for facile construction of other seven- or six-membered ring systems including dibenzotropones, dibenzooxepines, phenanthrenes, and quinolin-2(1H)-ones. This new heterogeneous gold(i) complex can be readily recovered through a simple filtration process and recycled at least eight times without any apparent decrease in catalytic efficiency.
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Affiliation(s)
- Yingying Du
- Key Laboratory of Functional Small Organic Molecule, Ministry of Education and College of Chemistry & Chemical Engineering, Jiangxi Normal University, Nanchang 330022, P. R. China.
| | - Bin Huang
- Key Laboratory of Functional Small Organic Molecule, Ministry of Education and College of Chemistry & Chemical Engineering, Jiangxi Normal University, Nanchang 330022, P. R. China.
| | - Jiajun Zeng
- Key Laboratory of Functional Small Organic Molecule, Ministry of Education and College of Chemistry & Chemical Engineering, Jiangxi Normal University, Nanchang 330022, P. R. China.
| | - Mingzhong Cai
- Key Laboratory of Functional Small Organic Molecule, Ministry of Education and College of Chemistry & Chemical Engineering, Jiangxi Normal University, Nanchang 330022, P. R. China.
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11
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Bejcek LP, Murelli RP. Synthesis of aryl-substituted 2-methoxyphenol derivatives from maltol-derived oxidopyrylium cycloadducts through an acid-mediated ring contraction cascade. Chem Commun (Camb) 2020; 56:3203-3205. [PMID: 32068199 PMCID: PMC7560963 DOI: 10.1039/c9cc09213g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Oxidopyrylium cycloadducts derived from maltol and aryl acetylenes undergo acid-mediated rearrangements to generate aryl-substituted 2-methoxyphenol (guaiacol) derivatives. Specifically, the cycloadducts react with boron trichloride to form 2-methoxy-5-arylphenol molecules, and with methane sulfonate to form 2-methoxy-4-aryl-6-methylphenol molecules.
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Affiliation(s)
- Lauren P Bejcek
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, NY, USA.
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12
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Bejcek LP, Garimallaprabhakaran AK, Suyabatmaz DM, Greer A, Hersh WH, Greer EM, Murelli RP. Maltol- and Allomaltol-Derived Oxidopyrylium Ylides: Methyl Substitution Pattern Kinetically Influences [5 + 3] Dimerization versus [5 + 2] Cycloaddition Reactions. J Org Chem 2019; 84:14670-14678. [PMID: 31603325 PMCID: PMC6982524 DOI: 10.1021/acs.joc.9b02137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Oxidopyrylium ylides are useful intermediates in synthetic organic chemistry because of their capability of forming structurally complex cycloadducts. They can also self-dimerize via [5 + 3] cycloaddition, which is an oft-reported side reaction that can negatively impact [5 + 2] cycloadduct yields and efficiency. In select instances, these dimers can be synthesized and used as the source of oxidopyrylium ylide, although the generality of this process remains unclear. Thus, how the substitution pattern governs both dimerization and cycloaddition reactions is of fundamental interest to probe factors to regulate them. The following manuscript details our findings that maltol-derived oxidopyrylium ylides (i.e., with ortho methyl substitution relative to oxide) can be trapped prior to dimerization more efficiently than the regioisomeric allomaltol-derived ylide (i.e., with a para methyl substitution relative to oxide). Density functional theory studies provide evidence in support of a sterically (kinetically) controlled mechanism, whereby gauche interactions between appendages of the approaching maltol-derived ylides are privileged by higher barriers for dimerization and thus are readily intercepted by dipolarophiles via [5 + 2] cycloadditions.
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Affiliation(s)
- Lauren P Bejcek
- Department of Chemistry , Brooklyn College, The City University of New York , Brooklyn , New York 11210 , United States
- PhD Program in Chemistry , The Graduate Center of the City University of New York , New York , New York 10016 , United States
| | - Aswin K Garimallaprabhakaran
- Department of Chemistry , Brooklyn College, The City University of New York , Brooklyn , New York 11210 , United States
| | - Duygu M Suyabatmaz
- Department of Chemistry , Brooklyn College, The City University of New York , Brooklyn , New York 11210 , United States
| | - Alexander Greer
- Department of Chemistry , Brooklyn College, The City University of New York , Brooklyn , New York 11210 , United States
- PhD Program in Chemistry , The Graduate Center of the City University of New York , New York , New York 10016 , United States
| | - William H Hersh
- PhD Program in Chemistry , The Graduate Center of the City University of New York , New York , New York 10016 , United States
- Department of Chemistry and Biochemistry , Queens College, City University of New York , Queens , New York 11367 , United States
| | - Edyta M Greer
- Department of Natural Sciences , Baruch College, City University of New York , New York , New York 10010 , United States
| | - Ryan P Murelli
- Department of Chemistry , Brooklyn College, The City University of New York , Brooklyn , New York 11210 , United States
- PhD Program in Chemistry , The Graduate Center of the City University of New York , New York , New York 10016 , United States
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13
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Agyemang NB, Kukla CR, Edwards TC, Li Q, Langen MK, Schaal A, Franson AD, Casals AG, Donald KA, Yu AJ, Donlin MJ, Morrison LA, Tavis JE, Murelli RP. Divergent synthesis of a thiolate-based α-hydroxytropolone library with a dynamic bioactivity profile. RSC Adv 2019; 9:34227-34234. [PMID: 33042521 PMCID: PMC7543996 DOI: 10.1039/c9ra06383h] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Here we describe a rapid and divergent synthetic route toward structurally novel αHTs functionalized with either one or two thioether or sulfonyl appendages. Evaluation of this library against hepatitis B and herpes simplex virus, as well as the pathogenic fungus Cryptococcus neoformans, and a human hepatoblastoma (HepDES19) revealed complementary biological profiles and new lead compounds with sub-micromolar activity against each pathogen.
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Affiliation(s)
- Nana B Agyemang
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York 11210, United States.,PhD Program in Chemistry, The Graduate Center of The City University of New York, New York, New York 10016, United States
| | - Cassandra R Kukla
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri 63104, United States
| | - Tiffany C Edwards
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri 63104, United States
| | - Qilan Li
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri 63104, United States
| | - Madison K Langen
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri, 63104, United States
| | - Alexandra Schaal
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri, 63104, United States
| | - Abaigeal D Franson
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri 63104, United States
| | - Andreu Gazquez Casals
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri 63104, United States
| | - Katherine A Donald
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri 63104, United States
| | - Alice J Yu
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri 63104, United States
| | - Maureen J Donlin
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri, 63104, United States
| | - Lynda A Morrison
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri 63104, United States.,Department of Internal Medicine, Saint Louis University School of Medicine, St. Louis, Missouri, 63110, United States
| | - John E Tavis
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, Missouri 63104, United States
| | - Ryan P Murelli
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York 11210, United States.,PhD Program in Chemistry, The Graduate Center of The City University of New York, New York, New York 10016, United States
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14
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Stasiak JP, Grigoryan A, Murelli RP. Spectrophotometric determination of α-hydroxytropolone p K a values: A structure-acidity relationship study. Tetrahedron Lett 2019; 60:1643-1645. [PMID: 32855576 PMCID: PMC7449261 DOI: 10.1016/j.tetlet.2019.05.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
α-Hydroxytropolones (αHTs) have a wealth of biological activity owing to their ability to serve as metalbinding fragments for many therapeutically valuable dinuclear metalloenzymes. They also have the potential to exist in as many as 4 protonation states under aqueous acidic or basic conditions. The following details how UV absorption can be used to generate pK a values on a series of αHTs. The studies also provide some knowledge into how the acidity and basicity change with some different functional groups. These studies thus provide new strategies and knowledge that could be valuable in leveraging αHTs as metal-binding fragments in drug-development pursuits.
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Affiliation(s)
- John P. Stasiak
- Department of Chemistry, Brooklyn College, The City University of New York, 2900 Bedford Avenue, Brooklyn, NY 11210, United States
| | - Alexandre Grigoryan
- Department of Chemistry, Brooklyn College, The City University of New York, 2900 Bedford Avenue, Brooklyn, NY 11210, United States
| | - Ryan P. Murelli
- Department of Chemistry, Brooklyn College, The City University of New York, 2900 Bedford Avenue, Brooklyn, NY 11210, United States
- Ph.D. Program in Chemistry, The Graduate Center, The City University of New York, 365 Fifth Avenue, New York, NY 10016, United States
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15
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Berkowitz AJ, Franson AD, Gazquez Cassals A, Donald KA, Yu AJ, Garimallaprabhakaran AK, Morrison LA, Murelli RP. Importance of lipophilicity for potent anti-herpes simplex virus-1 activity of α-hydroxytropolones. MEDCHEMCOMM 2019; 10:1173-1176. [PMID: 31391890 DOI: 10.1039/c9md00225a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 05/24/2019] [Indexed: 12/25/2022]
Abstract
We previously reported that troponoid compounds profoundly inhibit replication of herpes simplex virus (HSV)-1 and HSV-2 in cell culture, including acyclovir-resistant mutants. Synthesis of 26 alpha-hydroxylated tropolones (αHTs) led to a preliminary structure-activity relationship highlighting the potency of bi-phenyl side chains. Here, we explore the structure-activity relationship in more detail, with a focus on various biaryl and other lipophilic molecules. Along with our prior structure-function analysis, we present a refined structure-activity relationship that reveals the importance of the lipophilicity and nature of the side chain for potent anti-HSV-1 activity in cells. We expect this new information will help guide future optimization of αHTs as HSV antivirals.
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Affiliation(s)
- Alex J Berkowitz
- Department of Chemistry , Brooklyn College , The City University of New York , Brooklyn , NY , USA . .,Ph.D. Program in Chemistry , The Graduate Center , The City University of New York , New York , NY , USA
| | - Abaigeal D Franson
- Department of Molecular Microbiology and Immunology , Saint Louis University School of Medicine , St. Louis , MO , USA .
| | - Andreu Gazquez Cassals
- Department of Molecular Microbiology and Immunology , Saint Louis University School of Medicine , St. Louis , MO , USA .
| | - Katherine A Donald
- Department of Molecular Microbiology and Immunology , Saint Louis University School of Medicine , St. Louis , MO , USA .
| | - Alice J Yu
- Department of Molecular Microbiology and Immunology , Saint Louis University School of Medicine , St. Louis , MO , USA .
| | | | - Lynda A Morrison
- Department of Molecular Microbiology and Immunology , Saint Louis University School of Medicine , St. Louis , MO , USA . .,Department of Internal Medicine , Saint Louis University School of Medicine , St. Louis , MO , USA
| | - Ryan P Murelli
- Department of Chemistry , Brooklyn College , The City University of New York , Brooklyn , NY , USA . .,Ph.D. Program in Chemistry , The Graduate Center , The City University of New York , New York , NY , USA
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16
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Tavis JE, Zoidis G, Meyers MJ, Murelli RP. Chemical Approaches to Inhibiting the Hepatitis B Virus Ribonuclease H. ACS Infect Dis 2019; 5:655-658. [PMID: 29565562 DOI: 10.1021/acsinfecdis.8b00045] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Hepatitis B virus (HBV) chronically infects >250 million people and kills nearly a million annually, and current antivirals cannot clear the infection or adequately suppress disease. The virus replicates by reverse transcription, and the dominant antiviral drugs are nucleos(t)ide analogs that target the viral reverse transcriptase. We are developing antivirals targeting the other essential viral enzymatic activity, the ribonuclease H (RNaseH). HBV RNaseH inhibitors with efficacies in the low micromolar to nanomolar range against viral replication in culture have been identified in the α-hydroxytropolone and hydroxyimide chemotypes. Here, we review the promise of RNaseH inhibitors, their current structure-activity relationships, and challenges to optimizing the inhibitors into leads for clinical assessment.
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Affiliation(s)
- John E. Tavis
- Department of Molecular Microbiology and Immunology and Saint Louis University Liver Center, School of Medicine, Saint Louis University, 1100 S. Grand Blvd., Saint Louis, Missouri 63104, United States
| | - Grigoris Zoidis
- Department of Pharmaceutical Chemistry, School of Health Sciences, Faculty of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou, Athens, GR-15771, Greece
| | - Marvin J. Meyers
- Department of Chemistry, Saint Louis University, Monsanto Hall 125, 3501 Laclede Avenue, St. Louis, Missouri 63103, United States
| | - Ryan P. Murelli
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York 11210, United States
- PhD Program in Chemistry, The Graduate Center, The City University of New York, New York, New York 10016, United States
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17
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Hirsch DR, Metrano AJ, Stone EA, Storch G, Miller SJ, Murelli RP. Troponoid Atropisomerism: Studies on the Configurational Stability of Tropone-Amide Chiral Axes. Org Lett 2019; 21:2412-2415. [PMID: 30869521 PMCID: PMC6504963 DOI: 10.1021/acs.orglett.9b00707] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Configurationally stable, atropisomeric motifs are an important structural element in a number of molecules, including chiral ligands, catalysts, and molecular devices. Thus, understanding features that stabilize chiral axes is of fundamental interest throughout the chemical sciences. The following details the high rotational barriers about the Ar-C(O) bond of tropone amides, which significantly exceed those of analogous benzamides. These studies are supported by both experimental and computational rotational barrier measurements. We also report the resolution of an axially chiral α-hydroxytropolone amide into its individual atropisomers, and demonstrate its configurational stability at physiological pH and temperatures over 24 h.
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Affiliation(s)
- Danielle R. Hirsch
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York 11210, United States
- PhD Program in Chemistry, The Graduate Center of the City University of New York, New York, New York 10016 United States
| | - Anthony J. Metrano
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Elizabeth A. Stone
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Golo Storch
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Scott J. Miller
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Ryan P. Murelli
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York 11210, United States
- PhD Program in Chemistry, The Graduate Center of the City University of New York, New York, New York 10016 United States
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18
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Cao F, Orth C, Donlin MJ, Adegboyega P, Meyers MJ, Murelli RP, Elagawany M, Elgendy B, Tavis JE. Synthesis and Evaluation of Troponoids as a New Class of Antibiotics. ACS OMEGA 2018; 3:15125-15133. [PMID: 30533576 PMCID: PMC6275967 DOI: 10.1021/acsomega.8b01754] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 10/19/2018] [Indexed: 05/11/2023]
Abstract
Novel antibiotics are urgently needed. The troponoids [tropones, tropolones, and α-hydroxytropolones (α-HT)] can have anti-bacterial activity. We synthesized or purchased 92 troponoids and evaluated their antibacterial activities against Staphylococcus aureus, Escherichia coli, Acinetobacter baumannii, and Pseudomonas aeruginosa. Preliminary hits were assessed for minimum inhibitory concentrations (MIC80) and cytotoxicity (CC50) against human hepatoma cells. Sixteen troponoids inhibited S. aureus/E. coli/A. baumannii growth by ≥80% growth at <30 μM with CC50 values >50 μM. Two selected tropolones (63 and 285) inhibited 18 methicillin-resistant S. aureus (MRSA) strains with similar MIC80 values as against a reference strain. Two selected thiotropolones (284 and 363) inhibited multidrug-resistant (MDR) E. coli with MIC80 ≤30 μM. One α-HT (261) inhibited MDR-A. baumannii with MIC80 ≤30 μM. This study opens new avenues for development of novel troponoid antibiotics to address the critical need to combat MDR bacterial infections.
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Affiliation(s)
- Feng Cao
- John
Cochran Division, Department of Veterans Affairs Medical Center, 915 North Grand Blvd., St. Louis, Missouri 63106, United States
- E-mail: . Phone: +1 (314) 289-6358. Fax: +1(314) 289-7920 (F.C.)
| | - Cari Orth
- John
Cochran Division, Department of Veterans Affairs Medical Center, 915 North Grand Blvd., St. Louis, Missouri 63106, United States
| | - Maureen J. Donlin
- Edward
A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, United States
| | - Patrick Adegboyega
- John
Cochran Division, Department of Veterans Affairs Medical Center, 915 North Grand Blvd., St. Louis, Missouri 63106, United States
| | - Marvin J. Meyers
- Department
of Chemistry, Saint Louis University, St. Louis, Missouri 63104, United States
| | - Ryan P. Murelli
- Department
of Chemistry, Brooklyn College, The City
University of New York, Brooklyn, New York 11210, United States
- PhD
Program in Chemistry, The Graduate Center
of The City University of New York, New York 10016, United
States
| | - Mohamed Elagawany
- Center for
Clinical Pharmacology, Washington University
School of Medicine and St. Louis College of Pharmacy, St. Louis, Missouri 63110, United States
- Department
of Pharmaceutical Chemistry, Faculty of Pharmacy, Damanhour University, Damanhour 31111, Egypt
| | - Bahaa Elgendy
- Center for
Clinical Pharmacology, Washington University
School of Medicine and St. Louis College of Pharmacy, St. Louis, Missouri 63110, United States
- Chemistry
Department, Faculty of Science, Benha University, Benha 13518, Egypt
| | - John E. Tavis
- Department
of Molecular Microbiology and Immunology, The Saint Louis University Liver Center, Saint Louis University School
of Medicine, St. Louis, Missouri 63104, United
States
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19
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Credille CV, Dick BL, Morrison CN, Stokes RW, Adamek RN, Wu NC, Wilson IA, Cohen SM. Structure-Activity Relationships in Metal-Binding Pharmacophores for Influenza Endonuclease. J Med Chem 2018; 61:10206-10217. [PMID: 30351002 DOI: 10.1021/acs.jmedchem.8b01363] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Metalloenzymes represent an important target space for drug discovery. A limitation to the early development of metalloenzyme inhibitors has been the lack of established structure-activity relationships (SARs) for molecules that bind the metal ion cofactor(s) of a metalloenzyme. Herein, we employed a bioinorganic perspective to develop an SAR for inhibition of the metalloenzyme influenza RNA polymerase PAN endonuclease. The identified trends highlight the importance of the electronics of the metal-binding pharmacophore (MBP), in addition to MBP sterics, for achieving improved inhibition and selectivity. By optimization of the MBPs for PAN endonuclease, a class of highly active and selective fragments was developed that displays IC50 values <50 nM. This SAR led to structurally distinct molecules that also displayed IC50 values of ∼10 nM, illustrating the utility of a metal-centric development campaign in generating highly active and selective metalloenzyme inhibitors.
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Affiliation(s)
- Cy V Credille
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
| | - Benjamin L Dick
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
| | - Christine N Morrison
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
| | - Ryjul W Stokes
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
| | - Rebecca N Adamek
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
| | - Nicholas C Wu
- Department of Integrative Structural and Computational Biology , The Scripps Research Institute , La Jolla , California 92037 , United States
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology , The Scripps Research Institute , La Jolla , California 92037 , United States.,The Skaggs Institute for Chemical Biology , The Scripps Research Institute , La Jolla , California 92037 , United States
| | - Seth M Cohen
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
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20
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Miller JT, Zhao H, Masaoka T, Varnado B, Cornejo Castro EM, Marshall VA, Kouhestani K, Lynn AY, Aron KE, Xia A, Beutler JA, Hirsch DR, Tang L, Whitby D, Murelli RP, Le Grice SFJ. Sensitivity of the C-Terminal Nuclease Domain of Kaposi's Sarcoma-Associated Herpesvirus ORF29 to Two Classes of Active-Site Ligands. Antimicrob Agents Chemother 2018; 62:e00233-18. [PMID: 30061278 PMCID: PMC6153795 DOI: 10.1128/aac.00233-18] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 07/19/2018] [Indexed: 01/03/2023] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV), the etiological agent of Kaposi's sarcoma, belongs to the Herpesviridae family, whose members employ a multicomponent terminase to resolve nonparametric viral DNA into genome-length units prior to their packaging. Homology modeling of the ORF29 C-terminal nuclease domain (pORF29C) and bacteriophage Sf6 gp2 have suggested an active site clustered with four acidic residues, D476, E550, D661, and D662, that collectively sequester the catalytic divalent metal (Mn2+) and also provided important insight into a potential inhibitor binding mode. Using this model, we have expressed, purified, and characterized the wild-type pORF29C and variants with substitutions at the proposed active-site residues. Differential scanning calorimetry demonstrated divalent metal-induced stabilization of wild-type (WT) and D661A pORF29C, consistent with which these two enzymes exhibited Mn2+-dependent nuclease activity, although the latter mutant was significantly impaired. Thermal stability of WT and D661A pORF29C was also enhanced by binding of an α-hydroxytropolone (α-HT) inhibitor shown to replace divalent metal at the active site. For the remaining mutants, thermal stability was unaffected by divalent metal or α-HT binding, supporting their role in catalysis. pORF29C nuclease activity was also inhibited by two classes of small molecules reported to inhibit HIV RNase H and integrase, both of which belong to the superfamily of nucleotidyltransferases. Finally, α-HT inhibition of KSHV replication suggests ORF29 nuclease function as an antiviral target that could be combined with latency-activating compounds as a shock-and-kill antiviral strategy.
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Affiliation(s)
- Jennifer T Miller
- Basic Research Laboratory, National Cancer Institute, Frederick, Maryland, USA
| | - Haiyan Zhao
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA
| | - Takashi Masaoka
- Basic Research Laboratory, National Cancer Institute, Frederick, Maryland, USA
| | - Brittany Varnado
- Department of Chemistry, Brooklyn College, City University of New York, Brooklyn, New York, USA
| | - Elena M Cornejo Castro
- Viral Oncology Section, AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research sponsored by the National Cancer Institute, Frederick, Maryland, USA
| | - Vickie A Marshall
- Viral Oncology Section, AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research sponsored by the National Cancer Institute, Frederick, Maryland, USA
| | - Kaivon Kouhestani
- Basic Research Laboratory, National Cancer Institute, Frederick, Maryland, USA
| | - Anna Y Lynn
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA
| | - Keith E Aron
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA
| | - Anqi Xia
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA
| | - John A Beutler
- Molecular Targets Program, National Cancer Institute, Frederick, Maryland, USA
| | - Danielle R Hirsch
- Department of Chemistry, Brooklyn College, City University of New York, Brooklyn, New York, USA
- Molecular Targets Program, National Cancer Institute, Frederick, Maryland, USA
| | - Liang Tang
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA
| | - Denise Whitby
- Viral Oncology Section, AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research sponsored by the National Cancer Institute, Frederick, Maryland, USA
| | - Ryan P Murelli
- Department of Chemistry, Brooklyn College, City University of New York, Brooklyn, New York, USA
- Ph.D. Program in Chemistry, The Graduate Center of The City University of New York, New York, New York, USA
| | - Stuart F J Le Grice
- Basic Research Laboratory, National Cancer Institute, Frederick, Maryland, USA
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21
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Berkowitz AJ, Abdelmessih RG, Murelli RP. Amidation Strategy for Final-Step α-Hydroxytropolone Diversification. Tetrahedron Lett 2018; 59:3026-3028. [PMID: 30872871 PMCID: PMC6411066 DOI: 10.1016/j.tetlet.2018.06.063] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
α-Hydroxytropolones (αHTs) are excellent metalloenzyme-inhibiting fragments that have been the basis for the development of potent inhibitors of various therapeutically important enzymes. The following manuscript describes a final-step amidation approach for αHT diversification. The method takes advantage of a scalable, chromatography-free synthesis of a carboxylic acid-appended αHT, and in the present manuscript we describe the synthesis of eight amide-containing αHTs, three of which we envision using as chemical probes. We expect that the general strategy will find widespread usage in both chemical biology and medicinal chemistry studies on αHTs.
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Affiliation(s)
- Alex J. Berkowitz
- Department of Chemistry, Brooklyn College, The City University of New York, 2900 Bedford Avenue, Brooklyn, NY, 11210, United States
- Ph.D. Program in Chemistry, The Graduate Center, The City University of New York, 365 Fifth Avenue, New York, NY, 10016, United States
| | - Rudolf G. Abdelmessih
- Department of Chemistry, Brooklyn College, The City University of New York, 2900 Bedford Avenue, Brooklyn, NY, 11210, United States
| | - Ryan P. Murelli
- Department of Chemistry, Brooklyn College, The City University of New York, 2900 Bedford Avenue, Brooklyn, NY, 11210, United States
- Ph.D. Program in Chemistry, The Graduate Center, The City University of New York, 365 Fifth Avenue, New York, NY, 10016, United States
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22
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Salacz L, Girard N, Blond G, Suffert J. Synthesis of Polyheterocyclic Tropones by [2 + 2 + 2 + 1] Carbonylative Cycloaddition of Triynes. Org Lett 2018; 20:3915-3918. [DOI: 10.1021/acs.orglett.8b01496] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Laura Salacz
- Université de Strasbourg, CNRS, LIT UMR 7200, F-67000 Strasbourg, France
| | - Nicolas Girard
- Université de Strasbourg, CNRS, LIT UMR 7200, F-67000 Strasbourg, France
| | - Gaëlle Blond
- Université de Strasbourg, CNRS, LIT UMR 7200, F-67000 Strasbourg, France
| | - Jean Suffert
- Université de Strasbourg, CNRS, LIT UMR 7200, F-67000 Strasbourg, France
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23
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Bejcek LP, Murelli RP. Oxidopyrylium [5+2] Cycloaddition Chemistry: Historical Perspective and Recent Advances (2008-2018). Tetrahedron 2018; 74:2501-2521. [PMID: 30455508 PMCID: PMC6238658 DOI: 10.1016/j.tet.2018.04.006] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Lauren P Bejcek
- Department of Chemistry, Brooklyn College, City University of New York, Brooklyn, NY, Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY
| | - Ryan P Murelli
- Department of Chemistry, Brooklyn College, City University of New York, Brooklyn, NY, Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY
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24
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Abstract
α-Hydroxytropolones (αHTs) are troponoids that demonstrate inhibition against an array of therapeutically significant targets, making them potential drug leads for several human diseases. We have utilized a recently discovered one-pot three-component oxidopyrylium cycloaddition in a solid-supported synthesis of αHTs. Though the procedure is time efficient and generates assay-ready molecules, the system suffers from low yields and an inability to perform reaction modifications on resin-bound intermediates. In order to combat these issues with the solid-phase platform, we incorporated fluorous tags into our synthetic route. Through the implementation of fluorous phase chemistry, we demonstrate a substantial increase in the overall yield of αHTs, as well as an ability to execute metal-catalyzed cross coupling and amide coupling on fluorous tagged intermediates. We also show that tagged molecules can be separated from nonfluorous impurities, and vice versa, by utilizing fluorous liquid-liquid and solid-phase extractions. Hence, these proof-of-principle investigations describe the viability of a fluorous phase approach to αHT synthesis and its potential to serve as a combinatorial technique to produce structurally diverse substrates.
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Affiliation(s)
- Michael P. D’Erasmo
- Department of Chemistry, Brooklyn College, The City
University of New York, Brooklyn, New York 11210, United States
- PhD Program in Chemistry, The Graduate Center of The City
University of New York, New York, New York 10016, United States
| | - Ryan P. Murelli
- Department of Chemistry, Brooklyn College, The City
University of New York, Brooklyn, New York 11210, United States
- PhD Program in Chemistry, The Graduate Center of The City
University of New York, New York, New York 10016, United States
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25
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Dehghanpir SD, Birkenheuer CH, Yang K, Murelli RP, Morrison LA, Le Grice SFJ, Baines JD. Broad anti-herpesviral activity of α-hydroxytropolones. Vet Microbiol 2017; 214:125-131. [PMID: 29408023 DOI: 10.1016/j.vetmic.2017.12.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 12/20/2017] [Accepted: 12/22/2017] [Indexed: 01/02/2023]
Abstract
Herpesviruses are ubiquitous in animals and cause economic losses concomitant with many diseases. Most of the domestic animal herpesviruses are within the subfamily Alphaherpesvirinae, which includes human herpes simplex virus 1 (HSV-1). Suppression of HSV-1 replication has been reported with α-hydroxytropolones (αHTs), aromatic ring compounds that have broad bioactivity due to potent chelating activity. It is postulated that αHTs inhibit enzymes within the nucleotidyltransferase superfamily (NTS). These enzymes require divalent cations for nucleic acid cleavage activity. Potential targets include the nuclease component of the herpesvirus terminase (pUL15C), a highly conserved NTS-like enzyme that cleaves viral DNA into genomic lengths prior to packaging into capsids. Inhibition of pUL15C activity in biochemical assays by various αHTs previously revealed a spectrum of potencies. Interestingly, the most potent anti-pUL15C αHT inhibited HSV-1 replication to a limited extent in cell culture. The aim of this study was to evaluate three different αHT molecules with varying biochemical anti-pUL15C activity for a capacity to inhibit replication of veterinary herpesviruses (BoHV-1, EHV-1, and FHV-1) and HSV-1. Given the known discordant potencies between anti-pUL15C and HSV-1 replication inhibition, a second objective was to elucidate the mechanism of action of these compounds. The results show that αHTs broadly inhibit herpesviruses, with similar inhibitory effect against HSV-1, BoHV-1, EHV-1, and FHV-1. Based on immunoblotting, Southern blotting, and real-time qPCR, the compounds were found to specifically inhibit viral DNA replication. Thus, αHTs represent a new class of broadly active anti-herpesviral compounds with potential veterinary applications.
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Affiliation(s)
- Shannon D Dehghanpir
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, United States
| | - Claire H Birkenheuer
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, United States
| | - Kui Yang
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, United States
| | - Ryan P Murelli
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, NY, PhD Program in Chemistry, The Graduate Center, The City University of New York, New York, NY, United States
| | - Lynda A Morrison
- Department of Molecular Microbiology & Immunology, Saint Louis University School of Medicine,St. Louis, MO, United States
| | - Stuart F J Le Grice
- Center for Cancer Research, National Cancer Institute, Frederick, MD, United States
| | - Joel D Baines
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, United States.
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Hirsch DR, Schiavone DV, Berkowitz AJ, Morrison LA, Masaoka T, Wilson JA, Lomonosova E, Zhao H, Patel BS, Datla SH, Hoft SG, Majidi SJ, Pal RK, Gallicchio E, Tang L, Tavis JE, Le Grice SFJ, Beutler JA, Murelli RP. Synthesis and biological assessment of 3,7-dihydroxytropolones. Org Biomol Chem 2017; 16:62-69. [PMID: 29098212 PMCID: PMC5748270 DOI: 10.1039/c7ob02453c] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
3,7-Dihydroxytropolones (3,7-dHTs) are highly oxygenated troponoids that have been identified as lead compounds for several human diseases. To date, structure-function studies on these molecules have been limited due to a scarcity of synthetic methods for their preparation. New synthetic strategies towards structurally novel 3,7-dHTs would be valuable in further studying their therapeutic potential. Here we describe the successful adaptation of a [5 + 2] oxidopyrilium cycloaddition/ring-opening for 3,7-dHT synthesis, which we apply in the synthesis of a plausible biosynthetic intermediate to the natural products puberulic and puberulonic acid. We have also tested these new compounds in several biological assays related to human immunodeficiency virus (HIV), hepatitis B virus (HBV) and herpes simplex virus (HSV) in order to gain insight into structure-functional analysis related to antiviral troponoid development.
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Affiliation(s)
- D R Hirsch
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, 11210, USA.
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27
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Fuhr KN, Hirsch DR, Murelli RP, Brenner-Moyer SE. Catalytic Enantioselective Intermolecular [5 + 2] Dipolar Cycloadditions of a 3-Hydroxy-4-pyrone-Derived Oxidopyrylium Ylide. Org Lett 2017; 19:6356-6359. [PMID: 29148809 PMCID: PMC5831127 DOI: 10.1021/acs.orglett.7b03196] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The first catalytic enantioselective [5 + 2] dipolar cycloaddition of a 3-hydroxy-4-pyrone-derived oxidopyrylium ylide is described. These studies leveraged the recently recognized ability of oxidopyrylium dimers to serve as the source of ylide, which was found to be key to increasing yields and achieving enantiomeric excesses up to 99%. General reaction conditions were identified for an array of α,β-unsaturated aldehyde dipolarophiles. Reaction products possess four stereocenters, and subsequent reduction introduced a fifth contiguous stereocenter with total stereocontrol.
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Affiliation(s)
- Katherine N. Fuhr
- Department of Chemistry, Rutgers University, Newark, New Jersey, USA 07102
| | - Danielle R. Hirsch
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA 11210
- PhD Program in Chemistry, The Graduate Center, The City University of New York, New York, NY, USA 10016
| | - Ryan P. Murelli
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA 11210
- PhD Program in Chemistry, The Graduate Center, The City University of New York, New York, NY, USA 10016
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The Exonuclease Activity of Herpes Simplex Virus 1 UL12 Is Required for Production of Viral DNA That Can Be Packaged To Produce Infectious Virus. J Virol 2017; 91:JVI.01380-17. [PMID: 28956767 DOI: 10.1128/jvi.01380-17] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 09/21/2017] [Indexed: 01/23/2023] Open
Abstract
The herpes simplex virus (HSV) type I alkaline nuclease, UL12, has 5'-to-3' exonuclease activity and shares homology with nucleases from other members of the Herpesviridae family. We previously reported that a UL12-null virus exhibits a severe defect in viral growth. To determine whether the growth defect was a result of loss of nuclease activity or another function of UL12, we introduced an exonuclease-inactivating mutation into the viral genome. The recombinant virus, UL12 D340E (the D340E mutant), behaved identically to the null virus (AN-1) in virus yield experiments, exhibiting a 4-log decrease in the production of infectious virus. Furthermore, both viruses were severely defective in cell-to-cell spread and produced fewer DNA-containing capsids and more empty capsids than wild-type virus. In addition, DNA packaged by the viral mutants was aberrant, as determined by infectivity assays and pulsed-field gel electrophoresis. We conclude that UL12 exonuclease activity is essential for the production of viral DNA that can be packaged to produce infectious virus. This conclusion was bolstered by experiments showing that a series of natural and synthetic α-hydroxytropolones recently reported to inhibit HSV replication also inhibit the nuclease activity of UL12. Taken together, our results demonstrate that the exonuclease activity of UL12 is essential for the production of infectious virus and may be considered a target for development of antiviral agents.IMPORTANCE Herpes simplex virus is a major pathogen, and although nucleoside analogs such as acyclovir are highly effective in controlling HSV-1 or -2 infections in immunocompetent individuals, their use in immunocompromised patients is complicated by the development of resistance. Identification of additional proteins essential for viral replication is necessary to develop improved therapies. In this communication, we confirm that the exonuclease activity of UL12 is essential for viral replication through the analysis of a nuclease-deficient viral mutant. We demonstrate that the exonuclease activity of UL12 is essential for the production of viral progeny and thus provides an attractive, druggable enzymatic target.
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Lomonosova E, Daw J, Garimallaprabhakaran AK, Agyemang NB, Ashani Y, Murelli RP, Tavis JE. Efficacy and cytotoxicity in cell culture of novel α-hydroxytropolone inhibitors of hepatitis B virus ribonuclease H. Antiviral Res 2017. [PMID: 28633989 DOI: 10.1016/j.antiviral.2017.06.014] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Chronic Hepatitis B virus (HBV) infection is a major worldwide public health problem. Current direct-acting anti-HBV drugs target the HBV DNA polymerase activity, but the equally essential viral ribonuclease H (RNaseH) activity is unexploited as a drug target. Previously, we reported that α-hydroxytropolone compounds can inhibit the HBV RNaseH and block viral replication. Subsequently, we found that our biochemical RNaseH assay underreports efficacy of the α-hydroxytropolones against HBV replication. Therefore, we conducted a structure-activity analysis of 59 troponoids against HBV replication in cell culture. These studies revealed that antiviral efficacy is diminished by larger substitutions on the tropolone ring, identified key components in the substitutions needed for high efficacy, and revealed that cytotoxicity correlates with increased lipophilicity of the α-hydroxytropolones. These data provide key guidance for further optimization of the α-hydroxytropolone scaffold as novel HBV RNaseH inhibitors.
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Affiliation(s)
- Elena Lomonosova
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, MO, USA; Saint Louis University Liver Center, Saint Louis, MO, USA
| | - Jil Daw
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, MO, USA
| | | | - Nana B Agyemang
- Department of Chemistry, Brooklyn College, City University of New York, Brooklyn, NY, USA
| | - Yashkumar Ashani
- Department of Chemistry, Brooklyn College, City University of New York, Brooklyn, NY, USA
| | - Ryan P Murelli
- Department of Chemistry, Brooklyn College, City University of New York, Brooklyn, NY, USA; PhD Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, USA
| | - John E Tavis
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis, MO, USA; Saint Louis University Liver Center, Saint Louis, MO, USA.
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Troponoids Can Inhibit Growth of the Human Fungal Pathogen Cryptococcus neoformans. Antimicrob Agents Chemother 2017; 61:AAC.02574-16. [PMID: 28167553 DOI: 10.1128/aac.02574-16] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 02/01/2017] [Indexed: 12/18/2022] Open
Abstract
Cryptococcus neoformans is a pathogen that is common in immunosuppressed patients. It can be treated with amphotericin B and fluconazole, but the mortality rate remains 15 to 30%. Thus, novel and more effective anticryptococcal therapies are needed. The troponoids are based on natural products isolated from western red cedar, and have a broad range of antimicrobial activities. Extracts of western red cedar inhibit the growth of several fungal species, but neither western red cedar extracts nor troponoid derivatives have been tested against C. neoformans We screened 56 troponoids for their ability to inhibit C. neoformans growth and to assess whether they may be attractive candidates for development into anticryptococcal drugs. We determined MICs at which the compounds inhibited 80% of cryptococcal growth relative to vehicle-treated controls and identified 12 compounds with MICs ranging from 0.2 to 15 μM. We screened compounds with MICs of ≤20 μM for cytotoxicity in liver hepatoma cells. Fifty percent cytotoxicity values (CC50s) ranged from 4 to >100 μM. The therapeutic indexes (TI, CC50/MIC) for most of the troponoids were fairly low, with most being <8. However, two compounds had TI values that were >8, including a tropone with a TI of >300. These tropones are fungicidal and are not antagonistic when used in combination with fluconazole or amphotericin B. Inhibition by these two tropones remains unchanged under conditions favoring cryptococcal capsule formation. These data support the hypothesis that troponoids may be a productive scaffold for the development of novel anticryptococcal therapies.
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31
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D'Erasmo MP, Masaoka T, Wilson JA, Hunte EM, Beutler JA, Le Grice SFJ, Murelli RP. Traceless Solid-Phase α-Hydroxytropolone Synthesis. MEDCHEMCOMM 2016; 7:1789-1792. [PMID: 28090282 DOI: 10.1039/c6md00237d] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
α-Hydroxytropolones are established inhibitors of several therapeutically relevant binuclear metalloenzymes, and thus lead drug targets for various human diseases. We have leveraged a recently-disclosed three-component oxidopyrylium cycloaddition in the first solid-phase synthesis of α-hydroxytropolones. We also showed that, while minor impurities exist after cleavage and aqueous wash, the semi-crude products display activity in HIV RT-associated RNaseH enzymatic and cell-based assays consistent with pure molecules made in solution phase. These proof-of-principle studies demonstrate the feasibility of solid-phase α-hydroxytropolone synthesis and its potential to serve as a powerful platform for α-hydroxytropolone-based drug discovery and development.
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Affiliation(s)
- Michael P D'Erasmo
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA; PhD Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, USA
| | - Takashi Masaoka
- Basic Research Laboratory, National Cancer Institute, Frederick, MD, USA
| | - Jennifer A Wilson
- Molecular Targets Laboratory, National Cancer Institute, Frederick, MD, USA
| | - Errol M Hunte
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA
| | - John A Beutler
- Molecular Targets Laboratory, National Cancer Institute, Frederick, MD, USA
| | | | - Ryan P Murelli
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA; PhD Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, USA
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Murelli RP, D'Erasmo MP, Hirsch DR, Meck C, Masaoka T, Wilson JA, Zhang B, Pal RK, Gallicchio E, Beutler JA, Le Grice SFJ. Synthetic α-Hydroxytropolones as Inhibitors of HIV Reverse Transcriptase Ribonuclease H Activity. MEDCHEMCOMM 2016; 7:1783-1788. [PMID: 28093576 PMCID: PMC5234084 DOI: 10.1039/c6md00238b] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
HIV Reverse Transcriptase-associated ribonuclease H activity is a promising enzymatic target for drug development that has not been successfully targeted in the clinic. While the α-hydroxytropolone-containing natural products β-thujaplicinol and manicol have emerged as some of the most potent leads described to date, structure-function studies have been limited to the natural products and semi-synthetic derivatives of manicol. Thus, a library of α-hydroxytropolones synthesized through a convenient oxidopyrylium cycloaddition/ring-opening sequence have been tested in in vitro and cell-based assays, and have been analyzed using computational support. These studies reveal new synthetic α-hydroxytropolones that, unlike the natural product leads they are derived from, demonstrate protective antiviral activity in cellular assays.
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Affiliation(s)
- Ryan P Murelli
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA; PhD Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, USA
| | - Michael P D'Erasmo
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA; PhD Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, USA
| | - Danielle R Hirsch
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA; PhD Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, USA
| | - Christine Meck
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA; PhD Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, USA
| | - Takashi Masaoka
- Basic Research Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, USA
| | - Jennifer A Wilson
- Molecular Targets Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, USA
| | - Baofeng Zhang
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA
| | - Rajat K Pal
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA; PhD Program in Biochemistry, The Graduate Center of The City University of New York, New York, NY, USA
| | - Emilio Gallicchio
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA; PhD Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, USA; PhD Program in Biochemistry, The Graduate Center of The City University of New York, New York, NY, USA
| | - John A Beutler
- Molecular Targets Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, USA
| | - Stuart F J Le Grice
- Basic Research Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, USA
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33
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D’Erasmo MP, Meck C, Lewis CA, Murelli RP. Discovery and Development of a Three-Component Oxidopyrylium [5 + 2] Cycloaddition. J Org Chem 2016; 81:3744-51. [PMID: 27018974 PMCID: PMC5095581 DOI: 10.1021/acs.joc.6b00394] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
α-Hydroxy-γ-pyrone-based oxidopyrylium cycloaddition reactions are useful methods for accessing a highly diverse range of oxabicyclo[3.2.1]octane products. Intermolecular variants of the reaction require the formation of a methyl triflate-based pre-ylide salt that upon treatment with base in the presence of alkenes or alkynes leads to α-methoxyenone-containing bicyclic products. Herein, we describe our discovery that the use of ethanol-stabilized chloroform as solvent leads to the generation of α-ethoxyenone-containing bicyclic byproducts. This three-component process was further optimized by gently heating a mixture of a purified version of the oxidopyrylium dimer in the presence of an alcohol prior to addition of a dipolarophile. Using this convenient procedure, several new oxidopyrylium cycloaddition products can be generated in moderate yields. We also highlight the method in a tandem ring-opening/debenzylation method for the generation of α-hydroxytropolones.
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Affiliation(s)
- Michael P. D’Erasmo
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA
- PhD Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, USA
| | - Christine Meck
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA
- PhD Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, USA
| | - Chad A. Lewis
- Department of Chemistry, Cornell University, Ithaca, NY, USA
| | - Ryan P. Murelli
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA
- PhD Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, USA
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Synthetic α-Hydroxytropolones Inhibit Replication of Wild-Type and Acyclovir-Resistant Herpes Simplex Viruses. Antimicrob Agents Chemother 2016; 60:2140-9. [PMID: 26787704 DOI: 10.1128/aac.02675-15] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 01/14/2016] [Indexed: 12/18/2022] Open
Abstract
Herpes simplex virus 1 (HSV-1) and HSV-2 remain major human pathogens despite the development of anti-HSV therapeutics as some of the first antiviral drugs. Current therapies are incompletely effective and frequently drive the evolution of drug-resistant mutants. We recently determined that certain natural troponoid compounds such as β-thujaplicinol readily suppress HSV-1 and HSV-2 replication. Here, we screened 26 synthetic α-hydroxytropolones with the goals of determining a preliminary structure-activity relationship for the α-hydroxytropolone pharmacophore and providing a starting point for future optimization studies. Twenty-five compounds inhibited HSV-1 and HSV-2 replication at 50 μM, and 10 compounds inhibited HSV-1 and HSV-2 at 5 μM, with similar inhibition patterns and potencies against both viruses being observed. The two most powerful inhibitors shared a common biphenyl side chain, were capable of inhibiting HSV-1 and HSV-2 with a 50% effective concentration (EC50) of 81 to 210 nM, and also strongly inhibited acyclovir-resistant mutants. Moderate to low cytotoxicity was observed for all compounds (50% cytotoxic concentration [CC50] of 50 to >100 μM). Therapeutic indexes ranged from >170 to >1,200. These data indicate that troponoids and specifically α-hydroxytropolones are a promising lead scaffold for development as anti-HSV drugs provided that toxicity can be further minimized. Troponoid drugs are envisioned to be employed alone or in combination with existing nucleos(t)ide analogs to suppress HSV replication far enough to prevent viral shedding and to limit the development of or treat nucleos(t)ide analog-resistant mutants.
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35
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Masaoka T, Zhao H, Hirsch DR, D'Erasmo MP, Meck C, Varnado B, Gupta A, Meyers MJ, Baines J, Beutler JA, Murelli RP, Tang L, Le Grice SFJ. Characterization of the C-Terminal Nuclease Domain of Herpes Simplex Virus pUL15 as a Target of Nucleotidyltransferase Inhibitors. Biochemistry 2016; 55:809-19. [PMID: 26829613 DOI: 10.1021/acs.biochem.5b01254] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The natural product α-hydroxytropolones manicol and β-thujaplicinol inhibit replication of herpes simplex viruses 1 and 2 (HSV-1 and HSV-2, respectively) at nontoxic concentrations. Because these were originally developed as divalent metal-sequestering inhibitors of the ribonuclease H activity of HIV-1 reverse transcriptase, α-hydroxytropolones likely target related HSV proteins of the nucleotidyltransferase (NTase) superfamily, which share an "RNase H-like" fold. One potential candidate is pUL15, a component of the viral terminase molecular motor complex, whose C-terminal nuclease domain, pUL15C, has recently been crystallized. Crystallography also provided a working model for DNA occupancy of the nuclease active site, suggesting potential protein-nucleic acid contacts over a region of ∼ 14 bp. In this work, we extend crystallographic analysis by examining pUL15C-mediated hydrolysis of short, closely related DNA duplexes. In addition to defining a minimal substrate length, this strategy facilitated construction of a dual-probe fluorescence assay for rapid kinetic analysis of wild-type and mutant nucleases. On the basis of its proposed role in binding the phosphate backbone, studies with pUL15C variant Lys700Ala showed that this mutation affected neither binding of duplex DNA nor binding of small molecule to the active site but caused a 17-fold reduction in the turnover rate (kcat), possibly by slowing conversion of the enzyme-substrate complex to the enzyme-product complex and/or inhibiting dissociation from the hydrolysis product. Finally, with a view of pUL15-associated nuclease activity as an antiviral target, the dual-probe fluorescence assay, in combination with differential scanning fluorimetry, was used to demonstrate inhibition by several classes of small molecules that target divalent metal at the active site.
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Affiliation(s)
- Takashi Masaoka
- Basic Research Laboratory, National Cancer Institute , Frederick, Maryland 21702, United States
| | - Haiyan Zhao
- Department of Molecular Biosciences, University of Kansas , Lawrence, Kansas 66045, United States
| | - Danielle R Hirsch
- Department of Chemistry, Brooklyn College, City University of New York , Brooklyn, New York 11210, United States.,Ph.D. Program in Chemistry, The Graduate Center of the City University of New York , New York, New York 10016, United States
| | - Michael P D'Erasmo
- Department of Chemistry, Brooklyn College, City University of New York , Brooklyn, New York 11210, United States.,Ph.D. Program in Chemistry, The Graduate Center of the City University of New York , New York, New York 10016, United States
| | - Christine Meck
- Department of Chemistry, Brooklyn College, City University of New York , Brooklyn, New York 11210, United States.,Ph.D. Program in Chemistry, The Graduate Center of the City University of New York , New York, New York 10016, United States
| | - Brittany Varnado
- Department of Molecular Biosciences, University of Kansas , Lawrence, Kansas 66045, United States
| | - Ankit Gupta
- Department of Molecular Microbiology and Immunology, St. Louis University School of Medicine , St. Louis, Missouri 63104, United States
| | - Marvin J Meyers
- Department of Chemistry, St. Louis University , St. Louis, Missouri 63103, United States
| | - Joel Baines
- School of Veterinary Medicine, Louisiana State University , Baton Rouge, Louisiana 70803, United States
| | - John A Beutler
- Molecular Targets Laboratory, National Cancer Institute , Frederick, Maryland 21702, United States
| | - Ryan P Murelli
- Department of Chemistry, Brooklyn College, City University of New York , Brooklyn, New York 11210, United States.,Ph.D. Program in Chemistry, The Graduate Center of the City University of New York , New York, New York 10016, United States
| | - Liang Tang
- Department of Molecular Biosciences, University of Kansas , Lawrence, Kansas 66045, United States
| | - Stuart F J Le Grice
- Basic Research Laboratory, National Cancer Institute , Frederick, Maryland 21702, United States
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36
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Song W, Xi BM, Yang K, Tang W. Synthesis of Substituted Tropones by Sequential Rh-Catalyzed [5+2] Cycloaddition and Elimination. Tetrahedron 2015; 71:5979-5984. [PMID: 26456984 PMCID: PMC4597182 DOI: 10.1016/j.tet.2015.04.039] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Highly substituted tropones are prepared from cycloheptatrienes derived from Rh-catalyzed intermolecular [5+2] cycloaddition of 3-acyloxy-1,4-enynes and propargylic alcohols. The intermolecular [5+2] cycloaddition is highly regioselective for a variety of propargylic alcohols. Elimination of the cycloaddition products afforded various substituted tropones.
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Affiliation(s)
- Wangze Song
- School of Pharmacy, University of Wisconsin, 777 Highland Avenue, Madison, WI 53705-2222, USA
| | - Bao-min Xi
- School of Pharmacy, University of Wisconsin, 777 Highland Avenue, Madison, WI 53705-2222, USA
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, Guangdong Province, 510515, P. R. China
| | - Ka Yang
- School of Pharmacy, University of Wisconsin, 777 Highland Avenue, Madison, WI 53705-2222, USA
| | - Weiping Tang
- School of Pharmacy, University of Wisconsin, 777 Highland Avenue, Madison, WI 53705-2222, USA
- Department of Chemistry, University of Wisconsin, Madison, WI 53706, USA
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37
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Tavis JE, Lomonosova E. The hepatitis B virus ribonuclease H as a drug target. Antiviral Res 2015; 118:132-8. [PMID: 25862291 DOI: 10.1016/j.antiviral.2015.04.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 03/30/2015] [Accepted: 04/02/2015] [Indexed: 12/20/2022]
Abstract
Chronic hepatitis B virus (HBV) infection is a leading cause of hepatitis, liver failure, and hepatocellular carcinoma. An outstanding vaccine is available; however, the number of infections remains high. Current anti-HBV treatments with interferon α and nucleos(t)ide analogs clear the infection in only a small minority of patients, and either induce serious side-effects or are of very long duration. HBV is a small, enveloped DNA virus that replicates by reverse transcription via an RNA intermediate. The HBV ribonuclease H (RNaseH) is essential for viral replication, but it has not been exploited as a drug target. Recent low-throughput screening of compound classes with anti-Human Immunodeficiency Virus RNaseH activity led to identification of HBV RNaseH inhibitors in three different chemical families that block HBV replication. These inhibitors are promising candidates for development into new anti-HBV drugs. The RNaseH inhibitors may help improve treatment efficacy enough to clear the virus from the liver when used in combination with existing anti-HBV drugs and/or with other novel inhibitors under development. This article forms part of a symposium in Antiviral Research on "An unfinished story: from the discovery of the Australia antigen to the development of new curative therapies for hepatitis B."
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Affiliation(s)
- John E Tavis
- Department of Molecular Microbiology and Immunology, Saint Louis University Liver Center, United States.
| | - Elena Lomonosova
- Department of Molecular Microbiology and Immunology, Saint Louis University Liver Center, United States
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Kats-Kagan R, Herzon SB. The Discovery of a Novel Route to Highly Substituted α-Tropolones Enables Expedient Entry to the Core of the Gukulenins. Org Lett 2015; 17:2030-3. [DOI: 10.1021/acs.orglett.5b00841] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Roman Kats-Kagan
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Seth B. Herzon
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
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Liu N, Song W, Schienebeck CM, Zhang M, Tang W. Synthesis of Naturally Occurring Tropones and Tropolones. Tetrahedron 2014; 70:9281-9305. [PMID: 25400298 PMCID: PMC4228802 DOI: 10.1016/j.tet.2014.07.065] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Tropones and tropolones are an important class of seven-membered non-benzenoid aromatic compounds. They can be prepared directly by oxidation of seven-membered rings. They can also be derived from cyclization or cycloaddition of appropriate precursors followed by elimination or rearrangement. This review discusses the types of naturally occurring tropones and tropolones and outlines important methods developed for the synthesis of tropone and tropolone natural products.
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Affiliation(s)
- Na Liu
- School of Pharmacy, University of Wisconsin, 777 Highland Avenue, Madison, WI 53705
| | - Wangze Song
- School of Pharmacy, University of Wisconsin, 777 Highland Avenue, Madison, WI 53705
| | - Casi M. Schienebeck
- School of Pharmacy, University of Wisconsin, 777 Highland Avenue, Madison, WI 53705
| | - Min Zhang
- Innovative Drug Discovery Centre, Chongqing University, 55 Daxuecheng South Rd, Shapingba, Chongqing, 401331, P. R. China
| | - Weiping Tang
- School of Pharmacy, University of Wisconsin, 777 Highland Avenue, Madison, WI 53705
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, WI 53706
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Hydroxylated tropolones inhibit hepatitis B virus replication by blocking viral ribonuclease H activity. Antimicrob Agents Chemother 2014; 59:1070-9. [PMID: 25451058 DOI: 10.1128/aac.04617-14] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Hepatitis B virus (HBV) remains a major human pathogen despite the development of both antiviral drugs and a vaccine, in part because the current therapies do not suppress HBV replication far enough to eradicate the virus. Here, we screened 51 troponoid compounds for their ability to suppress HBV RNaseH activity and HBV replication based on the activities of α-hydroxytropolones against HIV RNaseH, with the goal of determining whether the tropolone pharmacophore may be a promising scaffold for anti-HBV drug development. Thirteen compounds inhibited HBV RNaseH, with the best 50% inhibitory concentration (IC50) being 2.3 μM. Similar inhibition patterns were observed against HBV genotype D and C RNaseHs, implying limited genotype specificity. Six of 10 compounds tested against HBV replication in culture suppressed replication via blocking of viral RNaseH activity, with the best 50% effective concentration (EC50) being 0.34 μM. Eighteen compounds inhibited recombinant human RNaseH1, and moderate cytotoxicity was observed for all compounds (50% cytotoxic concentration [CC50]=25 to 79 μM). Therapeutic indexes ranged from 3.8 to 94. Efficient inhibition required an intact α-hydroxytropolone moiety plus one or more short appendages on the tropolone ring, but a wide variety of constituents were permissible. These data indicate that troponoids and specifically α-hydroxytropolones are promising lead candidates for development as anti-HBV drugs, providing that toxicity can be minimized. Potential anti-RNaseH drugs are envisioned to be employed in combination with the existing nucleos(t)ide analogs to suppress HBV replication far enough to block genomic maintenance, with the goal of eradicating infection.
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Hirsch DR, Cox G, D'Erasmo MP, Shakya T, Meck C, Mohd N, Wright GD, Murelli RP. Inhibition of the ANT(2")-Ia resistance enzyme and rescue of aminoglycoside antibiotic activity by synthetic α-hydroxytropolones. Bioorg Med Chem Lett 2014; 24:4943-7. [PMID: 25283553 PMCID: PMC4798002 DOI: 10.1016/j.bmcl.2014.09.037] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2014] [Revised: 09/09/2014] [Accepted: 09/11/2014] [Indexed: 11/17/2022]
Abstract
Aminoglycoside-2"-O-nucleotidyltransferase ANT(2")-Ia is an aminoglycoside resistance enzyme prevalent among Gram-negative bacteria, and is one of the most common determinants of enzyme-dependant aminoglycoside-resistance. The following report outlines the use of our recently described oxidopyrylium cycloaddition/ring-opening strategy in the synthesis and profiling of a library of synthetic α-hydroxytropolones against ANT(2")-Ia. In addition, we show that two of these synthetic constructs are capable of rescuing gentamicin activity against ANT-(2")-Ia-expressing bacteria.
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Affiliation(s)
- Danielle R Hirsch
- Department of Chemistry, Brooklyn College, The City University of New York, 2900 Bedford Avenue, Brooklyn, NY 11210, United States; Department of Chemistry, The Graduate Center, The City University of New York, 365 Fifth Avenue, New York, NY 10016, United States
| | - Georgina Cox
- M. G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, ON L8N 4K1, Canada
| | - Michael P D'Erasmo
- Department of Chemistry, Brooklyn College, The City University of New York, 2900 Bedford Avenue, Brooklyn, NY 11210, United States; Department of Chemistry, The Graduate Center, The City University of New York, 365 Fifth Avenue, New York, NY 10016, United States
| | - Tushar Shakya
- M. G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, ON L8N 4K1, Canada
| | - Christine Meck
- Department of Chemistry, Brooklyn College, The City University of New York, 2900 Bedford Avenue, Brooklyn, NY 11210, United States; Department of Chemistry, The Graduate Center, The City University of New York, 365 Fifth Avenue, New York, NY 10016, United States
| | - Noushad Mohd
- Department of Chemistry, Brooklyn College, The City University of New York, 2900 Bedford Avenue, Brooklyn, NY 11210, United States
| | - Gerard D Wright
- M. G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, ON L8N 4K1, Canada
| | - Ryan P Murelli
- Department of Chemistry, Brooklyn College, The City University of New York, 2900 Bedford Avenue, Brooklyn, NY 11210, United States; Department of Chemistry, The Graduate Center, The City University of New York, 365 Fifth Avenue, New York, NY 10016, United States.
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Mei G, Yuan H, Gu Y, Chen W, Chung LW, Li CC. Dearomative Indole [5+2] Cycloaddition Reactions: Stereoselective Synthesis of Highly Functionalized Cyclohepta[b]indoles. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201406278] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Mei G, Yuan H, Gu Y, Chen W, Chung LW, Li CC. Dearomative Indole [5+2] Cycloaddition Reactions: Stereoselective Synthesis of Highly Functionalized Cyclohepta[b]indoles. Angew Chem Int Ed Engl 2014; 53:11051-5. [DOI: 10.1002/anie.201406278] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Indexed: 11/11/2022]
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Meck C, D'Erasmo MP, Hirsch DR, Murelli RP. The biology and synthesis of α-hydroxytropolones. MEDCHEMCOMM 2014; 5:842-852. [PMID: 25089179 PMCID: PMC4114738 DOI: 10.1039/c4md00055b] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
α-Hydroxytropolones are a subclass of the troponoid family of natural products that are of high interest due to their broad biological activity and potential as treatment options for several diseases. Despite this promise, there have been scarce synthetic chemistry-driven optimization studies on the molecules. The following review highlights key developments in the biological studies conducted on α-hydroxytropolones to date, including the few synthetic chemistry-driven optimization studies. In addition, we provide an overview of the methods currently available to access these molecules. This review is intended to serve as a resource for those interested in biological activity of α-hydroxytropolones, and inspire the development of new synthetic methods and strategies that could aid in this pursuit.
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Affiliation(s)
- Christine Meck
- Brooklyn College, City University of New York, Department of Chemistry, 2900 Bedford 4 Avenue, Brooklyn, New York, USA
| | - Michael P D'Erasmo
- Brooklyn College, City University of New York, Department of Chemistry, 2900 Bedford 4 Avenue, Brooklyn, New York, USA
| | - Danielle R Hirsch
- Brooklyn College, City University of New York, Department of Chemistry, 2900 Bedford 4 Avenue, Brooklyn, New York, USA
| | - Ryan P Murelli
- Brooklyn College, City University of New York, Department of Chemistry, 2900 Bedford 4 Avenue, Brooklyn, New York, USA
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Williams YD, Meck C, Mohd N, Murelli RP. Triflic acid-mediated rearrangements of 3-methoxy-8-oxabicyclo[3.2.1]octa-3,6-dien-2-ones: synthesis of methoxytropolones and furans. J Org Chem 2013; 78:11707-13. [PMID: 24171600 PMCID: PMC3909939 DOI: 10.1021/jo401617r] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Methoxytropolones are useful scaffolds for therapeutic development because of their known biological activity and established value in the synthesis of α-hydroxytropolones. Upon treatment with triflic acid, a series of 3-methoxy-8-oxabicyclo[3.2.1]octa-3,6-dien-2-ones rearrange rapidly and cleanly to form methoxytropolones. Interestingly, bicycles that are derived from dimethyl acetylenedicarboxylate (R(2) = R(3) = CO2Me) instead form furans as the major product.
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Affiliation(s)
- Yvonne D. Williams
- Department of Chemistry, Brooklyn College, The City University of New York, 2900 Bed-ford Avenue, Brooklyn College, Brooklyn, New York, 11210, United StatesDepartment of Chemistry, The Graduate Center, The City University of New York, 365 Fifth Avenue, New York, NY 10016, United States
| | - Christine Meck
- Department of Chemistry, Brooklyn College, The City University of New York, 2900 Bed-ford Avenue, Brooklyn College, Brooklyn, New York, 11210, United StatesDepartment of Chemistry, The Graduate Center, The City University of New York, 365 Fifth Avenue, New York, NY 10016, United States
| | - Noushad Mohd
- Department of Chemistry, Brooklyn College, The City University of New York, 2900 Bed-ford Avenue, Brooklyn College, Brooklyn, New York, 11210, United StatesDepartment of Chemistry, The Graduate Center, The City University of New York, 365 Fifth Avenue, New York, NY 10016, United States
| | - Ryan P. Murelli
- Department of Chemistry, Brooklyn College, The City University of New York, 2900 Bed-ford Avenue, Brooklyn College, Brooklyn, New York, 11210, United StatesDepartment of Chemistry, The Graduate Center, The City University of New York, 365 Fifth Avenue, New York, NY 10016, United States
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Maekawa H, Nagakubo K, Nishi M, Nishimura M, Nagahara D. Magnesium-Promoted Reductive Silylation and Acylation of Tropone and Tropone Acetal. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2013. [DOI: 10.1246/bcsj.20130156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Hirofumi Maekawa
- Department of Materials Science and Technology, Nagaoka University of Technology
| | - Keisuke Nagakubo
- Department of Materials Science and Technology, Nagaoka University of Technology
| | - Midori Nishi
- Department of Materials Science and Technology, Nagaoka University of Technology
| | - Makoto Nishimura
- Department of Materials Science and Technology, Nagaoka University of Technology
| | - Daisuke Nagahara
- Department of Materials Science and Technology, Nagaoka University of Technology
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