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Pal D, Lal P. Tropolones and Thailandepsin B as Lead-like Natural Compounds in the Development of Potent and Selective Histone Deacetylase Inhibitors. Curr Drug Targets 2023; 24:698-717. [PMID: 37424350 DOI: 10.2174/1389450124666230707144251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 05/31/2023] [Accepted: 06/21/2023] [Indexed: 07/11/2023]
Abstract
BACKGROUND Tropolone and thailandepsin B are naturally occurring substances that are primarily isolated from fungi and plants, although they can also be found in certain bacteria. Tropolones belong to an important class of aromatic compounds with a seven-membered nonbenzenoid ring structure. Thailandepsins are a group of natural products that were initially discovered in the culture broth of the Gram-negative bacterium Burkholderia thailandensis. Tropolonebased structures have been identified in over 200 natural compounds, ranging from simple tropolone derivatives to complex multicyclic systems like pycnidione and pyrerubrine A. These natural compounds exhibit a diverse range of pharmacological effects, including antibacterial, antifungal, insecticidal, phytotoxic, anti-inflammatory, antimitotic, anti-diabetic, enzyme inhibitory, anticancer, cytoprotective, and ROS scavenging properties. It is worth noting that thujaplicane, a compound similar to tropolone, displays all of the listed biological activities except for antimitotic action, which has only been observed in one natural tropolone compound, colchicine. Tropolone can be synthesized from commercially available seven-membered rings or derived through various cyclization and cycloaddition reactions. Thailandepsin B, on the other hand, can be synthesized by macro-lactonization of the corresponding secoacid, followed by the formation of internal disulfide bonds. It is important to mention that thailandepsin B exhibits different selective inhibition profiles compared to FK228. OBJECTIVE We investigated the HDAC inhibitory activity of the Tropolones and Thailandepsin B and discussed the biosynthesis of the naturally occurring compounds and their synthetic scheme. RESULTS AND CONCLUSION It has been observed that Tropolone derivatives act as isoenzyme-selective inhibitors of proven anticancer drug targets, histone deacetylases (HDACs). Some monosubstituted tropolones show remarkable levels of selectivity for HDAC2 and strongly inhibit the growth of T-lymphocyte cell lines. And Thailandepsins have different selective inhibition profiles than FK228. They exhibit comparable inhibitory activities to FK228 against human HDAC1, HDAC2, HDAC3, HDAC6, HDAC7, and HDAC9, but less potent inhibitory activities than FK228 toward HDAC4 and HDAC8, the latter of which may be useful. Thailandepsins possess potent cytotoxic activities toward some types of cell lines.
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Affiliation(s)
- Dilipkumar Pal
- Department of Pharmaceutical Sciences, Guru Ghasidash Vishwavidyalaya (A Central University), Bilaspur, C.G., 495 009, India
| | - Padum Lal
- Department of Pharmaceutical Sciences, Guru Ghasidash Vishwavidyalaya (A Central University), Bilaspur, C.G., 495 009, India
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2
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Lyczko K, Lyczko M, Banasiewicz M, Wegrzynska K, Ziółko A, Baraniak A, Dobrowolski JC. Thallium(I) Tropolonates: Synthesis, Structure, Spectral Characteristics, and Antimicrobial Activity Compared to Lead(II) and Bismuth(III) Analogues. Molecules 2021; 27:molecules27010183. [PMID: 35011415 PMCID: PMC8746424 DOI: 10.3390/molecules27010183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 12/27/2021] [Accepted: 12/27/2021] [Indexed: 11/16/2022] Open
Abstract
Synthesis, single-crystal X-ray determination diffraction and FT-IR, NMR (1H, 13C, 19F and 205Tl), UV–vis, and luminescence spectra characteristics were described for series of thallium(I) compounds: thallium(I) triflate (Tl(OTf)), 1:1 co-crystals of thallium(I) triflate and tropolone (Htrop), Tl(OTf)·Htrop, as well as simple thallium(I) chelates: Tl(trop) (1), Tl(5-metrop) (2), Tl(hino) (3), with Htrop, 5-methyltropolone (5-meHtrop), 4-isopropyltropolone (hinokitiol, Hhino), respectively, and additionally more complex {Tl@[Tl(hino)]6}(OTf) (4) compound. Comparison of their antimicrobial activity with selected lead(II) and bismuth(III) analogs and free ligands showed that only bismuth(III) complexes demonstrated significant antimicrobial activity, from two- to fivefold larger than the free ligands.
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Affiliation(s)
- Krzysztof Lyczko
- Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland; (M.L.); (J.C.D.)
- Correspondence:
| | - Monika Lyczko
- Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland; (M.L.); (J.C.D.)
| | | | - Karolina Wegrzynska
- National Medicines Institute, Chełmska 30/34, 00-725 Warsaw, Poland; (K.W.); (A.Z.); (A.B.)
| | - Anna Ziółko
- National Medicines Institute, Chełmska 30/34, 00-725 Warsaw, Poland; (K.W.); (A.Z.); (A.B.)
| | - Anna Baraniak
- National Medicines Institute, Chełmska 30/34, 00-725 Warsaw, Poland; (K.W.); (A.Z.); (A.B.)
| | - Jan Cz. Dobrowolski
- Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland; (M.L.); (J.C.D.)
- National Medicines Institute, Chełmska 30/34, 00-725 Warsaw, Poland; (K.W.); (A.Z.); (A.B.)
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Duan Y, Petzold M, Saleem‐Batcha R, Teufel R. Bacterial Tropone Natural Products and Derivatives: Overview of their Biosynthesis, Bioactivities, Ecological Role and Biotechnological Potential. Chembiochem 2020; 21:2384-2407. [PMID: 32239689 PMCID: PMC7497051 DOI: 10.1002/cbic.201900786] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 04/02/2020] [Indexed: 12/05/2022]
Abstract
Tropone natural products are non-benzene aromatic compounds of significant ecological and pharmaceutical interest. Herein, we highlight current knowledge on bacterial tropones and their derivatives such as tropolones, tropodithietic acid, and roseobacticides. Their unusual biosynthesis depends on a universal CoA-bound precursor featuring a seven-membered carbon ring as backbone, which is generated by a side reaction of the phenylacetic acid catabolic pathway. Enzymes encoded by separate gene clusters then further modify this key intermediate by oxidation, CoA-release, or incorporation of sulfur among other reactions. Tropones play important roles in the terrestrial and marine environment where they act as antibiotics, algaecides, or quorum sensing signals, while their bacterial producers are often involved in symbiotic interactions with plants and marine invertebrates (e. g., algae, corals, sponges, or mollusks). Because of their potent bioactivities and of slowly developing bacterial resistance, tropones and their derivatives hold great promise for biomedical or biotechnological applications, for instance as antibiotics in (shell)fish aquaculture.
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Affiliation(s)
- Ying Duan
- Faculty of BiologyUniversity of Freiburg79104FreiburgGermany
| | - Melanie Petzold
- Faculty of BiologyUniversity of Freiburg79104FreiburgGermany
| | | | - Robin Teufel
- Faculty of BiologyUniversity of Freiburg79104FreiburgGermany
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Li Q, Lomonosova E, Donlin MJ, Cao F, O'Dea A, Milleson B, Berkowitz AJ, Baucom JC, Stasiak JP, Schiavone DV, Abdelmessih RG, Lyubimova A, Fraboni AJ, Bejcek LP, Villa JA, Gallicchio E, Murelli RP, Tavis JE. Amide-containing α-hydroxytropolones as inhibitors of hepatitis B virus replication. Antiviral Res 2020; 177:104777. [PMID: 32217151 PMCID: PMC7199283 DOI: 10.1016/j.antiviral.2020.104777] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 03/16/2020] [Accepted: 03/18/2020] [Indexed: 12/19/2022]
Abstract
The Hepatitis B Virus (HBV) ribonuclease H (RNaseH) is a promising but unexploited drug target. Here, we synthesized and analyzed a library of 57 amide-containing α-hydroxytropolones (αHTs) as potential leads for HBV drug development. Fifty percent effective concentrations ranged from 0.31 to 54 μM, with selectivity indexes in cell culture of up to 80. Activity against the HBV RNaseH was confirmed in semi-quantitative enzymatic assays with recombinant HBV RNaseH. The compounds were overall poorly active against human ribonuclease H1, with 50% inhibitory concentrations of 5.1 to >1,000 μM. The αHTs had modest activity against growth of the fungal pathogen Cryptococcus neoformans, but had very limited activity against growth of the Gram - bacterium Escherichia coli and the Gram + bacterium Staphylococcus aureus, indicating substantial selectivity for HBV. A molecular model of the HBV RNaseH templated against the Ty3 RNaseH was generated. Docking the compounds to the RNaseH revealed the anticipated binding pose with the divalent cation coordinating motif on the compounds chelating the two Mn++ ions modeled into the active site. These studies reveal that that amide αHTs can be strong, specific HBV inhibitors that merit further assessment toward becoming anti-HBV drugs.
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Affiliation(s)
- Qilan Li
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, 1100 S. Grand Blvd, Saint Louis, MO, 63104, USA
| | - Elena Lomonosova
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, 1100 S. Grand Blvd, Saint Louis, MO, 63104, USA.
| | - Maureen J Donlin
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, 1100 S. Grand Blvd, Saint Louis, MO, 63104, USA.
| | - Feng Cao
- John Cochran Division, Department of Veterans Affairs Medical Center, Saint Louis, MO, USA.
| | - Austin O'Dea
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, 1100 S. Grand Blvd, Saint Louis, MO, 63104, USA.
| | - Brienna Milleson
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, 1100 S. Grand Blvd, Saint Louis, MO, 63104, USA
| | - Alex J Berkowitz
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, NY, 11210, USA; Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, 11210, USA.
| | - John-Charles Baucom
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, NY, 11210, USA; Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, 11210, USA.
| | - John P Stasiak
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, NY, 11210, USA.
| | - Daniel V Schiavone
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, NY, 11210, USA; Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, 11210, USA.
| | - Rudolf G Abdelmessih
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, NY, 11210, USA.
| | - Anastasiya Lyubimova
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, NY, 11210, USA.
| | - Americo J Fraboni
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, NY, 11210, USA.
| | - Lauren P Bejcek
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, NY, 11210, USA; Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, 11210, USA.
| | - Juan A Villa
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, 1100 S. Grand Blvd, Saint Louis, MO, 63104, USA.
| | - Emilio Gallicchio
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, NY, 11210, USA; Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, 11210, USA; Program in Biochemistry, The Graduate Center of The City University of New York, New York, NY, 11210, USA.
| | - Ryan P Murelli
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, NY, 11210, USA; Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, 11210, USA; Program in Biochemistry, The Graduate Center of The City University of New York, New York, NY, 11210, USA.
| | - John E Tavis
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, 1100 S. Grand Blvd, Saint Louis, MO, 63104, USA.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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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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7
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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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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Tsao YT, Huang YF, Kuo CY, Lin YC, Chiang WC, Wang WK, Hsu CW, Lee CH. Hinokitiol Inhibits Melanogenesis via AKT/mTOR Signaling in B16F10 Mouse Melanoma Cells. Int J Mol Sci 2016; 17:248. [PMID: 26901194 PMCID: PMC4783978 DOI: 10.3390/ijms17020248] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 02/04/2016] [Accepted: 02/15/2016] [Indexed: 02/05/2023] Open
Abstract
H inokitiol purified from the heartwood of cupressaceous plants has had various biological functions of cell differentiation and growth. Hinokitiol has been demonstrated as having an important role in anti-inflammation and anti-bacteria effect, suggesting that it is potentially useful in therapies for hyperpigmentation. Previously, hinokitiol inhibited the production of melanin by inhibiting tyrosinase activity. The autophagic signaling pathway can induce hypopigmentation. This study is warranted to investigate the mechanism of hinokitiol-induced hypopigmentation through autophagy in B16F10 melanoma cells. The melanin contents and expression of microthphalmia associated transcription factor (MITF) and tyrosinase were inhibited by treatment with hinokitiol. Moreover, the phosphorylation of the protein express levels of phospho-protein kinase B (P-AKT) and phospho-mammalian targets of rapamycin (P-mTOR) were reduced after hinokitiol treatment. In addition, the microtubule associated protein 1 light chain 3 (LC3) -II and beclin 1 (autophagic markers) were increased after the B16F10 cell was treated with hinokitiol. Meanwhile, hinokitiol decreased cellular melanin contents in a dose-dependent manner. These findings establish that hinokitiol inhibited melanogenesis through the AKT/mTOR signaling pathway.
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Affiliation(s)
- Yu-Tzu Tsao
- Division of Nephrology, Department of Medicine, Taoyuan General Hospital, Taoyuan 330, Taiwan.
- Institute of Clinical Medicine, National Yang-Ming University, Taipei 11221, Taiwan.
| | - Yu-Fen Huang
- Department of Microbiology, School of Medicine, China Medical University, Taichung 404, Taiwan.
| | - Chun-Yu Kuo
- Graduate Institute of Basic Medical Science, School of Medicine, China Medical University, Taichung 404, Taiwan.
| | - Yu-Chiang Lin
- Graduate Institute of Basic Medical Science, School of Medicine, China Medical University, Taichung 404, Taiwan.
| | - Wei-Cheng Chiang
- Department of Environmental Engineering and Science, Feng Chia University, Taichung 40407, Taiwan.
| | - Wei-Kuang Wang
- Department of Environmental Engineering and Science, Feng Chia University, Taichung 40407, Taiwan.
| | - Chia-Wei Hsu
- Graduate Institute of Basic Medical Science, School of Medicine, China Medical University, Taichung 404, Taiwan.
| | - Che-Hsin Lee
- Department of Microbiology, School of Medicine, China Medical University, Taichung 404, Taiwan.
- Graduate Institute of Basic Medical Science, School of Medicine, China Medical University, Taichung 404, Taiwan.
- Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung 804, Taiwan.
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Shaala LA, Youssef DTA. Identification and bioactivity of compounds from the fungus Penicillium sp. CYE-87 isolated from a marine tunicate. Mar Drugs 2015; 13:1698-709. [PMID: 25815893 PMCID: PMC4413182 DOI: 10.3390/md13041698] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 03/13/2015] [Accepted: 03/18/2015] [Indexed: 11/26/2022] Open
Abstract
In the course of our continuous interest in identifying bioactive compounds from marine microbes, we have investigated a tunicate-derived fungus, Penicillium sp. CYE-87. A new compound with the 1,4-diazepane skeleton, terretrione D (2), together with the known compounds, methyl-2-([2-(1H-indol-3-yl)ethyl]carbamoyl)acetate (1), tryptamine (3), indole-3-carbaldehyde (4), 3,6-diisobutylpyrazin-2(1H)-one (5) and terretrione C (6), were isolated from Penicillium sp. CYE-87. The structures of the isolated compounds were established by spectral analysis, including 1D (1H, 13C) and 2D (COSY, multiplicity edited-HSQC and HMBC) NMR and HRESIMS, as well as comparison of their NMR data with those in the literature. The compounds were evaluated for their antimigratory activity against the human breast cancer cell line (MDA-MB-231) and their antiproliferation activity against HeLa cells. Compounds 2 and 6 showed significant antimigratory activity against MDA-MB-231, as well as antifungal activity against C. albicans.
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Affiliation(s)
- Lamiaa A Shaala
- Natural Products Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
- Suez Canal University Hospital, Suez Canal University, Ismailia 51522, Egypt.
| | - Diaa T A Youssef
- Department of Natural Products, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
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Ma J, Pawar RS, Grundel E, Mazzola EP, Ridge CD, Masaoka T, Le Grice SFJ, Wilson J, Beutler JA, Krynitsky AJ. Sesquiterpenoid tropolone glycosides from Liriosma ovata. J Nat Prod 2015; 78:315-319. [PMID: 25587934 PMCID: PMC7709799 DOI: 10.1021/np5006696] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Two new sesquiterpenoid tropolone glycosides, liriosmasides A (1) and B (2), along with two known compounds, secoxyloganin and oplopanpheside C, were isolated from a methanol extract of the roots of Liriosma ovata. The structures of 1 and 2 were elucidated by spectroscopic methods including 1D and 2D NMR and by high-resolution mass spectrometry involving an ultra-high-performance liquid chromatography-quadrupole-orbital ion trap mass spectrometric (UHPLC-Q-Orbitrap MS) method. Compound 1 showed weak inhibitory activity against HIV RNase H.
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Affiliation(s)
- Jun Ma
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, 5100 Paint Branch Parkway, College Park, Maryland 20740, United States
| | - Rahul S. Pawar
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, 5100 Paint Branch Parkway, College Park, Maryland 20740, United States
| | - Erich Grundel
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, 5100 Paint Branch Parkway, College Park, Maryland 20740, United States
| | - Eugene P. Mazzola
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, 5100 Paint Branch Parkway, College Park, Maryland 20740, United States
| | - Clark D. Ridge
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, 5100 Paint Branch Parkway, College Park, Maryland 20740, United States
| | - Takashi Masaoka
- RT Biochemistry Section, HIV Drug Resistance Program, National Cancer Institute at Frederick, Frederick, Maryland 21702, United States
| | - Stuart F. J. Le Grice
- RT Biochemistry Section, HIV Drug Resistance Program, National Cancer Institute at Frederick, Frederick, Maryland 21702, United States
| | - Jennifer Wilson
- Molecular Targets Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, Maryland 21702, United States
| | - John A. Beutler
- Molecular Targets Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, Maryland 21702, United States
| | - Alexander J. Krynitsky
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, 5100 Paint Branch Parkway, College Park, Maryland 20740, United States
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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13
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Shibata H, Nagamine T, Wang Y, Ishikawa T, Sawa Y. Generation of Reactive Oxygen Species from Hinokitiol under Near-UV Irradiation. Biosci Biotechnol Biochem 2014; 67:1996-8. [PMID: 14519989 DOI: 10.1271/bbb.67.1996] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Near-UV irradiation caused the decomposition of hinokitiol in an aqueous solution. During the photochemical reaction, the distinct electron spin resonance signal characteristic of the adduct of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) with the hydroxyl radical was accompanied by small signals corresponding to the adduct of DMPO with the superoxide anion radical. More than 95% of Escherichia coli cells were killed by the incubation with hinokitiol under near-UV irradiation by BLB fluorescent lamps. These results indicated the generation of reactive oxygen species during photochemical reaction of hinokitiol under near-UV irradiation.
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Affiliation(s)
- Hitoshi Shibata
- Department of Life Science and Biotechnology, Faculty of Life and Environmental Science, Shimane University, Matsue, Japan.
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14
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Sekine S, Shimodaira C, Uesawa Y, Kagaya H, Kanda Y, Ishihara M, Amano O, Sakagami H, Wakabayashi H. Quantitative structure-activity relationship analysis of cytotoxicity and anti-UV activity of 2-aminotropones. Anticancer Res 2014; 34:1743-1750. [PMID: 24692705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
BACKGROUND We newly synthesized twenty 2-aminotropones with different lengths of methylene units, with or without introduction of isopropyl group at C-4 position of the cycloheptatriene ring, which were then subjected to quantitative structure-activity relationship (QSAR) analysis. MATERIALS AND METHODS Viable cell number was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The tumor specificity was determined by the ratio of the mean CC50 (50% cytotoxic concentration) for the normal cells (human gingival fibroblast, HGF) to that of the human oral squamous cell carcinoma (OSCC) cell line (Ca9-22) derived from gingival tissue. Anti-UV activity (SI) was determined by the ratio of CC50 to EC50 (the concentration that increased the viability of UV-irradiated cells to 50%) using HSC-2 OSCC cells. Physico-chemical, structural, and quantum-chemical parameters were calculated based on conformations optimized by the LowModeMD method followed by the Discrete Fourier Transform (DFT) method. Fine-cell structure was observed by transmission electron microscopy. RESULTS 2-Aminotropones induced cytotoxicity, accompanied by the production of many rough endoplasmic reticula with enlarged lacuna and vacuolated mitochondria. Their cytotoxicity was a positive function of the number of methylene units and hydrophobicity. Anti-UV activity showed a good correlation with lowest unoccupied molecular orbital (LUMO) energy, but not with the length of methylene units. All twenty 2-aminotropones induced a very low level of hormetic growth stimulation at lower concentrations. CONCLUSION Different types of chemical descriptors may be applicable to estimating the cytotoxicity and anti-UV activity of 2-aminotropones.
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Affiliation(s)
- Shota Sekine
- Faculty of Science, Josai University, Sakado, Saitama 350-0295, Japan. /
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15
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Ononye SN, Vanheyst MD, Giardina C, Wright DL, Anderson AC. Studies on the antiproliferative effects of tropolone derivatives in Jurkat T-lymphocyte cells. Bioorg Med Chem 2014; 22:2188-93. [PMID: 24613456 PMCID: PMC4011186 DOI: 10.1016/j.bmc.2014.02.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 02/13/2014] [Indexed: 01/09/2023]
Abstract
Thujaplicins are tropolone-derived natural products with antiproliferative properties. We recently reported that certain tropolones potently and selectively target histone deacetylases (HDAC) and inhibit the growth of hematological cell lines. Here, we investigated the mechanisms by which these compounds exert their antiproliferative activity in comparison with the pan-selective HDAC inhibitor, vorinostat, using Jurkat T-cell leukemia cells. The tropolones appear to work through a mechanism distinct from vorinostat. These studies suggest that tropolone derivatives may serve as selective epigenetic modulators of hematological cells with potential applications as anti-leukemic or anti-inflammatory agents.
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Affiliation(s)
- Sophia N Ononye
- Department of Pharmaceutical Sciences, University of Connecticut, 69 N. Eagleville Rd., Storrs, CT 06269, United States
| | - Michael D Vanheyst
- Department of Pharmaceutical Sciences, University of Connecticut, 69 N. Eagleville Rd., Storrs, CT 06269, United States
| | - Charles Giardina
- Department of Pharmaceutical Sciences, University of Connecticut, 69 N. Eagleville Rd., Storrs, CT 06269, United States
| | - Dennis L Wright
- Department of Pharmaceutical Sciences, University of Connecticut, 69 N. Eagleville Rd., Storrs, CT 06269, United States
| | - Amy C Anderson
- Department of Pharmaceutical Sciences, University of Connecticut, 69 N. Eagleville Rd., Storrs, CT 06269, United States.
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16
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Lee YS, Choi KM, Kim W, Jeon YS, Lee YM, Hong JT, Yun YP, Yoo HS. Hinokitiol inhibits cell growth through induction of S-phase arrest and apoptosis in human colon cancer cells and suppresses tumor growth in a mouse xenograft experiment. J Nat Prod 2013; 76:2195-202. [PMID: 24308647 DOI: 10.1021/np4005135] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Hinokitiol (1), a tropolone-related natural compound, induces apoptosis and has anti-inflammatory, antioxidant, and antitumor activities. In this study, the inhibitory effects of 1 were investigated on human colon cancer cell growth and tumor formation of xenograft mice. HCT-116 and SW-620 cells derived from human colon cancers were found to be similarly susceptible to 1, with IC50 values of 4.5 and 4.4 μM, respectively. Compound 1 induced S-phase arrest in the cell cycle progression and decreased the expression levels of cyclin A, cyclin E, and Cdk2. Conversely, 1 increased the expression of p21, a Cdk inhibitor. Compound 1 decreased Bcl-2 expression and increased the expression of Bax, and cleaved caspase-9 and -3. The effect of 1 on tumor formation when administered orally was evaluated in male BALB/c-nude mice implanted intradermally separately with HCT-116 and SW-620 cells. Tumor volumes and tumor weights in the mice treated with 1 (100 mg/kg) were decreased in both cases. These results suggest that the suppression of tumor formation by compound 1 in human colon cancer may occur through cell cycle arrest and apoptosis.
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Affiliation(s)
- Youn-Sun Lee
- Department of Biology Education, College of Education, Chungbuk National University , Cheongju 361-763, Korea
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17
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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18
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Cavazza M, Cifelli M, Domenici V, Funaioli T, Mennucci B, Veracini CA, Zandomeneghi M. Synthesis, chiroptical properties and density functional theory calculations of 3,3'-biphenyl-2,2'-bitropone. Chirality 2013; 25:648-55. [PMID: 23828068 DOI: 10.1002/chir.22191] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 04/25/2013] [Indexed: 11/07/2022]
Abstract
The synthesis of new bitropone derivatives, namely, 3,3'-biphenyl-2,2'-bitropone and 7,7'-biphenyl-2,2'-bitropone, are reported. Isolation of enantiomers arising from restricted rotation around the C-C bond connecting the tropone moieties was attempted by means of chiral high performance liquid chromatography (HPLC). No separation was obtained for 7,7'-biphenyl-2,2'-bitropone. For 3,3'-biphenyl-2,2'-bitropone, difficulties were encountered because of the low separation factor of the peaks and the presence of a rapid racemization process. However, quantitative chiroptical data on the antipodes were obtained by linking a circular dichroism (CD) spectrometer and a UV-vis spectrophotometric detector in series to the HPLC instrument. The analysis of the CD and UV-vis spectra in terms of absolute conformations was done with the help of theoretical calculations performed at the Density Functional Theory (DFT) level. The most stable conformations of the 3,3'-biphenyl-2,2'-bitropone in its ground state were obtained. Starting from these minimum energy conformations, it was possible to compute theoretical CD and UV absorption spectra that fit well with the experimental ones. From this comparison the absolute configuration to the antipodes was assigned. Finally, the effect of the presence of the two lateral phenyl substituents on the structure of the bitropone and hence on the CD spectrum is discussed.
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Affiliation(s)
- Marino Cavazza
- Dipartimento di Chimica e Chimica Industriale, via Risorgimento 35, 56126 Pisa, Italy
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19
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Fullagar JL, Garner AL, Struss AK, Day JA, Martin DP, Yu J, Cai X, Janda KD, Cohen SM. Antagonism of a zinc metalloprotease using a unique metal-chelating scaffold: tropolones as inhibitors of P. aeruginosa elastase. Chem Commun (Camb) 2013; 49:3197-9. [PMID: 23482955 PMCID: PMC3618488 DOI: 10.1039/c3cc41191e] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Tropolone emerged from the screening of a chelator fragment library (CFL) as an inhibitor of the Zn(2+)-dependent virulence factor, Pseudomonas aeruginosa elastase (LasB). Based on this initial hit, a series of substituted tropolone-based LasB inhibitors was prepared, and a compound displaying potent activity in vitro and in a bacterial swarming assay was identified. Importantly, this inhibitor was found to be specific for LasB over other metalloenzymes, validating the usage of tropolone as a viable scaffold for identifying first-in-class LasB inhibitors.
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Affiliation(s)
- Jessica L. Fullagar
- Departments of Chemistry and Immunology and Microbial Science, The Skaggs Institute for Chemical Biology, The Worm Institute for Research and Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, USA;Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA 92093
| | - Amanda L. Garner
- Departments of Chemistry and Immunology and Microbial Science, The Skaggs Institute for Chemical Biology, The Worm Institute for Research and Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, USA;Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA 92093
| | - Anjali K. Struss
- Departments of Chemistry and Immunology and Microbial Science, The Skaggs Institute for Chemical Biology, The Worm Institute for Research and Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, USA;Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA 92093
| | - Joshua A. Day
- Departments of Chemistry and Immunology and Microbial Science, The Skaggs Institute for Chemical Biology, The Worm Institute for Research and Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, USA;Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA 92093
| | - David P. Martin
- Departments of Chemistry and Immunology and Microbial Science, The Skaggs Institute for Chemical Biology, The Worm Institute for Research and Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, USA;Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA 92093
| | - Jing Yu
- Departments of Chemistry and Immunology and Microbial Science, The Skaggs Institute for Chemical Biology, The Worm Institute for Research and Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, USA;Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA 92093
| | - Xiaoqing Cai
- Departments of Chemistry and Immunology and Microbial Science, The Skaggs Institute for Chemical Biology, The Worm Institute for Research and Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, USA;Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA 92093
| | - Kim D. Janda
- Departments of Chemistry and Immunology and Microbial Science, The Skaggs Institute for Chemical Biology, The Worm Institute for Research and Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, USA;Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA 92093
| | - Seth M. Cohen
- Departments of Chemistry and Immunology and Microbial Science, The Skaggs Institute for Chemical Biology, The Worm Institute for Research and Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, USA;Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA 92093
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20
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Abstract
α-Hydroxytropolones are a class of molecules with therapeutic potential against several human diseases. However, structure-activity relationship studies on these molecules have been limited due to a scarcity of efficient synthetic methods to access them. It is demonstrated herein that α-hydroxytropolones can be generated through a BCl(3)-mediated ring-opening/aromatization/demethylation process on 8-oxabicyclo[3.2.1]octenes. Used in conjunction with an improved method based on established oxidopyrylium dipolar cycloadditions, several polysubstituted α-hydroxytropolones can be accessed in three steps from readily available α-hydroxy-γ-pyrones.
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Affiliation(s)
- Christine Meck
- Department of Chemistry, Brooklyn College, The City University of New York, 2900 Bedford Avenue, Brooklyn College 11210
- Department of Chemistry, The Graduate Center, The City University of New York, 365 Fifth Avenue, New York, NY 10016
| | - Noushad Mohd
- Department of Chemistry, Brooklyn College, The City University of New York, 2900 Bedford Avenue, Brooklyn College 11210
| | - Ryan P. Murelli
- Department of Chemistry, Brooklyn College, The City University of New York, 2900 Bedford Avenue, Brooklyn College 11210
- Department of Chemistry, The Graduate Center, The City University of New York, 365 Fifth Avenue, New York, NY 10016
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21
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Fujisaki R, Kamei K, Yamamura M, Nishiya H, Inouye S, Takahashi M, Abe S. In vitro and in vivo anti-plasmodial activity of essential oils, including hinokitiol. Southeast Asian J Trop Med Public Health 2012; 43:270-279. [PMID: 23082579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Abstract. The anti-plasmodial activity of 47 essential oils and 10 of their constituents were screened for in vitro activity against Plasmodium falciparum. Five of these essential oils (sandalwood, caraway, monarda, nutmeg, and Thujopsis dolabrata var. hondai) and 2 constituents (thymoquinone and hinokitiol) were found to be active against P. falciparum in vitro, with 50% inhibitory concentration (IC50) values equal to or less than 1.0 microg/ml. Furthermore, in vivo analysis using a rodent model confirmed the anti-plasmodial potential of subcutaneously administered sandalwood oil, and percutaneously administered hinokitiol and caraway oil against rodent P. berghei. Notably, these oils showed no efficacy when administered orally, intraperitoneally or intravenously. Caraway oil and hinokitiol dissolved in carrier oil, applied to the skin of hairless mice caused high levels in the blood, with concentrations exceeding their IC50 values.
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Affiliation(s)
- Ryuichi Fujisaki
- Teikyo University Hospital, School of Medicine, Teikyo University, Tokyo, Hachioji, Tokyo, Japan
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22
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Kantoh K, Ono M, Nakamura Y, Nakamura Y, Hashimoto K, Sakagami H, Wakabayashi H. Hormetic and anti-radiation effects of tropolone-related compounds. In Vivo 2010; 24:843-851. [PMID: 21164042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We have previously investigated a total of 173 azulene-, tropolone- and azulenequinone-related compounds for their tumor-specificity and anti-inflammatory activity. In this study, we selected six compounds that showed tumor-specific cytotoxicity (referred to as group I compounds) and five compounds that inhibited nitric oxide production by activated macrophages (referred to as group II compounds) to investigate their possible hormetic and anti-radiation effects. We have established three oral normal cell type, human gingival fibroblast HGF-1, pulp cell HPC-1 and periodontal ligament fibroblast HPLF-1, from extracted teeth and periodontal tissue. These normal cells expressed p53 protein, regardless of the growth stage (either at growing or near confluent phase), more than oral squamous cell carcinoma cell line (HSC-2). Group I compounds slightly stimulated the growth of HPL-1 cells only at restricted durations and concentrations, but did not affect that of HGF-1 and HPC-1 cells, suggesting the minor hormetic effects displayed by these compounds. We established a new evaluation system for UV-induced cellular damage using an intact HSC-2 cell system in which sodium ascorbate (vitamin C) and gallic acid, but not N-acetyl-l-cysteine nor catalase, exerted protective effects. Three group I compounds and two group II compounds significantly protected the cells from UV-induced injury, suggesting their possible anti-UV effect.
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Affiliation(s)
- Kaori Kantoh
- Faculty of Science, Josai University, Sakado, Saitama 350-0295, Japan
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23
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Nishinaga T, Aono T, Isomura E, Watanabe S, Miyake Y, Miyazaki A, Enoki T, Miyasaka H, Otani H, Iyoda M. Structural, electronic and magnetic properties of Cu(ii) complexes of 2-substituted tropones bearing a ferrocenyl group at 5-position. Dalton Trans 2010; 39:2293-300. [PMID: 20162203 DOI: 10.1039/b912255a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Tohru Nishinaga
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan.
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24
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Ishihara M, Wakabayashi H, Motohashi N, Sakagami H. Quantitative structure-cytotoxicity relationship of newly synthesized tropolones determined by a semiempirical molecular-orbital method (PM5). Anticancer Res 2010; 30:129-133. [PMID: 20150627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A semiempirical molecular-orbital method (CONFLEX/PM5) was applied to delineate the relationship between the cytotoxicity (evaluated by 50% cytotoxic concentration, CC(50)) of twenty-four tropolone-related compounds and their molecular weight or one of the following eleven chemical descriptors: the heat of formation (COSMO, non-COSMO; kcal/mole), stability of hydration (=COSMO-nonCOSMO (DeltaH); kcal/mole), dipole moment (D), hydrophobicity (log P), highest occupied molecular orbital energy (E(HOMO); eV), lowest unoccupied molecular orbital energy (E(LUMO); eV), absolute hardness [eta=(E(LUMO)-E(HOMO))/2; eV)], absolute electron negativity [chi=-(E(LUMO)+E(HOMO))/2; eV], reactivity index (omega=chi(2)/2eta; eV), surface area (A(2)) and volume (A(3)) of the molecule. No good correlation was found with the unseparated twenty-four compounds all together, but modest to high correlation was found after separation into three different groups of compounds, depending on the structural similarity. Particular descriptors could be used to evaluate the biological activity of newly synthesized tropolones.
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Affiliation(s)
- Mariko Ishihara
- Division of Basic Chemistry, Department of Oral Biology and Tissue Engineering, Meikai University School of Dentistry, Sakado, Saitama 350-0283, Japan.
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25
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Abstract
A concise approach to the core skeleton of the welwitindolinone alkaloids was developed on the basis of sequential cycloaddition reactions. First, a palladium catalyzed enantioselective [6 + 3] trimethylenemethane cycloaddition onto a tropone nucleus was used to generate the requisite bicyclo[4.3.1]decadiene. Subsequent modifications to the cycloadduct allowed for an intramolecular [4 + 2] cycloaddition to generate the oxindole and complete the core of the natural product family.
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Affiliation(s)
- Barry M Trost
- Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA.
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26
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Randau KP, Sproll S, Lerche H, Bracher F. Pernambucone, a new tropone derivative from Croton argyroglossum. Pharmazie 2009; 64:350-351. [PMID: 19530449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Two tropone derivatives, orobanone (1), previously isolated from Orobanche rapum-genistae, and the new natural product pernambucone (3,8-dimethyl-5-isopropyl-2,3-dihydro-1H-azulene-1,6-dione, 2), were isolated from the sterm bark of Croton argyroglossum. The structures were elucidated from spectroscopic data.
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Affiliation(s)
- K P Randau
- Department Pharmazie-Zentrum für Pharmaforschung, Ludwig-Maximilians-Universität, München, Germany
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27
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Narita T, Suga A, Kobayashi M, Hashimoto K, Sakagami H, Motohashi N, Kurihara T, Wakabayashi H. Tumor-specific cytotoxicity and type of cell death induced by benzo[b]cyclohept[e][1,4]oxazine and 2-aminotropone derivatives. Anticancer Res 2009; 29:1123-1130. [PMID: 19414354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A total of twenty benzo[b]cyclohept[e] [1,4]oxazines and their S-analogs, and 2-aminotropone derivatives were investigated for their cytotoxicity against three human normal cells and four tumor cell lines. These compounds showed moderate tumor-specific cytotoxicity. The cytotoxicity was enhanced by bromination at the tropone ring and replacement by formylbenzene. The cytotoxicity of 2-(2-hydroxyanilino) tropone was enhanced by introduction of bromine or isopropyl group to the tropone ring. The presence of a hydroxyl group at ortho or para-position should be necessary for the appearance of cytotoxicity and tumor-specificity. The highly active derivatives, 7-bromo-2-(4-hydroxyanilino)tropone [16] and 4-isopropyl-2-(2-hydroxyanilino)tropone [20], induced internucleosomal DNA fragmentation and caspase-3, -8 and -9 activation in human promyelocytic leukemia HL-60 cells, but only at concentrations twice or four times higher than CC(50) values. These compounds induced no discernible DNA fragmentation, and activated caspases much more weakly in human oral squamous cell carcinoma HSC-2 cells. Both [16] and [20] failed to induce the production of acidic organelles, a marker of autophagy, in contrast to the nutritional starvation. These data demonstrated that 2-aminotropones showed relatively higher tumor-specificity than benzo[b]cyclohept[e] [1,4]oxazine, and that 2-aminotropones induced little or no apoptotic cell death in oral squamous cell carcinoma, in contrast to HL-60 cells.
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Affiliation(s)
- Taichi Narita
- Faculty of Science, Josai University, Sakado, Saitama 350-0295, Japan
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Kwon S, Shimoda K, Hamada H, Ishihara K, Masuoka N, Hamada H. High production of beta-thujaplicin glycosides by immobilized plant cells of Nicotiana tabacum. Acta Biol Hung 2008; 59:347-55. [PMID: 18839701 DOI: 10.1556/abiol.59.2008.3.8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
beta-Thujaplicin (hinokitiol) is a tropolone derivative present in the heartwood of cupressaceous plants and is used as a medicine, a food additive, and a preservative, and in cosmetics as hair tonic. The cultured plant cells of Nicotiana tabacum glycosylated beta-thujaplicin to two glucosides, 4-isopropyltropolone 2-O-beta-D-glucoside (6%) and 6-isopropyltropolone 2-O-beta-D-glucoside (12%), and two gentiobiosides, 4-isopropyltropolone 2-O-beta-D-gentiobioside (2%) and 6-isopropyltropolone 2-O-beta-D-gentiobioside (5%) after 48 h incubation. The use of immobilized cells of N. tabacum in sodium alginate gel much improved the yield of the products; the glycosylation of beta-thujaplicin with immobilized N. tabacum gave the glycoside products, 4-isopropyltropolone 2-O-beta-D-glucoside (11%), 4-isopropyltropolone 2-O-beta-D-gentiobioside (6%), 6-isopropyltropolone 2-O-beta-D-glucoside (20%), and 6-isopropyltropolone 2-O-beta-D-gentiobioside (10%). On the other hand, 4-isopropyltropolone 2-O-beta-D-glucoside (14%), 4-isopropyltropolone 2-O-beta-D-gentiobioside (7%), 6-isopropyltropolone 2-O-beta-D-glucoside (33%), and 6-isopropyltropolone 2-O-beta-D-gentiobioside (13%) were obtained through the biotransformation with immobilized cells in the medium without iron ions. In comparison with the case of bioconversion in the normal medium containing iron ions, removal of iron ions improved the yields of products.
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Affiliation(s)
- S Kwon
- Department of Applied Science, Faculty of Science, Okayama University of Science, 1-1 Ridai-cho, Okayama 700-0005, Japan
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Ayers S, Zink DL, Powell JS, Brown CM, Grund A, Bills GF, Platas G, Thompson D, Singh SB. Noreupenifeldin, a tropolone from an unidentified ascomycete. J Nat Prod 2008; 71:457-459. [PMID: 18095654 DOI: 10.1021/np070513k] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Noreupenifeldin ( 2), a new monotropolone derivative of the bistropolone eupenifeldin ( 1), was isolated from an unidentified ascomycete by bioassay-guided fractionation as part of our search for new anthelmintics. The structure of 1 was confirmed by comparison with literature data. The structure of 2 was elucidated from MS and 1D and 2D NMR data. Compounds 1 and 2 are diastereomers of pycnidione ( 3) and epolone A ( 4), respectively. Compounds 1- 3 were evaluated for their anthelmintic activity against the parasitic worm Hemonchus contortus. Compounds 1 and 3 exhibited modest in vitro activity, showing EC 90 50 and 83 microg/mL, respectively, in reducing motility of L3 larvae of H. contortus. Compound 2 was inactive, indicating that the second tropolone moiety is required for activity.
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Affiliation(s)
- Sloan Ayers
- Merck Research Laboratories, Rahway, New Jersey 07065, USA
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Varin M, Chiaroni A, Lallemand JY, Iorga B, Guillou C. A New Access to Dihydrotropones through Ring Expansion of Spirocyclohexadienones: Synthesis and Mechanism. J Org Chem 2007; 72:6421-6. [PMID: 17655358 DOI: 10.1021/jo070594p] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this paper we report the rearrangement of spirocyclohexadienones into dihydrotropones in basic conditions as a new method for the preparation of seven-membered ring ketones, which are key building blocks for the synthesis of tropoloalkaloids. DFT calculations and deuterium labeling studies support the mechanism we propose for this rearrangement, involving the ring opening of a spirocyclopropane intermediate followed by successive base-catalyzed 1,3-hydrogen shifts. The X-ray structure of the resulting dihydrotropone shows near-perfect planarity and the conjugation gain is likely to be the driving force of the reaction.
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Affiliation(s)
- Marie Varin
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, F-91198 Gif sur Yvette, France
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Abstract
Potassium N-isopropyl-2-(isopropylamino)troponiminate, K{(iPr)2ATI}, and potassium N-cyclohexyl-2-(cyclohexylamino)troponiminate, K{(Cy)2ATI}, were synthesized by treatment of the neutral ligands with an excess of KH in THF. Reaction of the potassium reagents with [AuClPPh3] resulted in the gold complexes [Au{(iPr)2ATI}PPh3] and [Au{(Cy)2ATI}PPh3]. The solid-state structures of both compounds, in which the ligands are arranged in plane, show distorted trigonal planar coordinated gold atoms. Potassium 2-(isopropylamino)troponate (K(iPrAT)) and the cyclohexyl analogue (K(CyAT)) were obtained by deprotonation of corresponding aminotropones with KH. In an analogous fashion the gold complexes of composition [Au(iPrAT)PPh3] and [Au(CyAT)PPh3] were prepared by reaction of K(iPrAT) and K(CyAT) with [AuClPPh3], respectively.
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Affiliation(s)
- Jenni Meiners
- Institut für Chemie und Biochemie, Freie Universität Berlin, Fabeckstrasse 34-36, 14195 Berlin, Germany
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Lyczko K, Starosta W, Persson I. Influence of pH and Counteranion on the Structure of Tropolonato−Lead(II) Complexes: Structural and Infrared Characterization of Formed Lead Compounds. Inorg Chem 2007; 46:4402-10. [PMID: 17474735 DOI: 10.1021/ic061561f] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Reactions of tropolone with lead(II) trifluoromethanesulfonate, perchlorate, and nitrate in water/methanol mixtures at pH below 1.0 lead to the formation of three different polymeric lead(II) complexes, [Pb(trop)(CF3SO3)(H2O)]n (1), [Pb3(trop)4(ClO4)2]n (2), and [Pb2(trop)2(NO3)2(CH3OH)]n (3), respectively. On the other hand, if the reactions are performed at pH above 2.0, the dimeric compound [Pb(trop)2]2 (4) is obtained independently of the lead(II) salt used, as long as lead(II) does not form any strong complexes with the counterion. The crystal structures of these compounds have been determined by single-crystal X-ray diffraction. The structure of solid tetrakis(tropolonato)lead(IV), Pb(trop)4 (5), has been studied by means of the EXAFS technique because it was not possible to obtain sufficiently large single crystals. In the polymeric structures, the counterions are coordinated to the lead(II) ions and act as bridges. The tropolonato ligand behaves as a chelating agent and a tri- or tetraconnective bridge. The total coordination number of the lead(II) ion is five in compound 4, seven in 1 and 3, and eight in 2, and the lead(IV) ion in 5 is eight-coordinated. The 6s2 lone electron pair on the lead(II) ion seems to be stereochemically active in all lead(II) complexes studied. All compounds have been characterized by IR spectroscopy as well.
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Affiliation(s)
- Krzysztof Lyczko
- Institute of Nuclear Chemistry and Technology, Dorodna 16, PL-03-195 Warsaw, Poland.
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Inamori Y, Morita Y, Sakagami Y, Okabe T, Ishida N. The excellence of Aomori Hiba (Hinokiasunaro) in its use as building materials of Buddhist temples and Shinto shrines. Biocontrol Sci 2006; 11:49-54. [PMID: 16789546 DOI: 10.4265/bio.11.49] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Five hinokitiol-related compounds (hinokitiol (beta-thujaplicin), beta-dolabrin, gamma-thujaplicin, 4-acetyltropolone and alpha -thujaplicin) isolated from the acid oil of Aomori Hiba (Thujopsis dolabrata Sieb. et Zucc. var hondai MAKINO) showed clear antifungal activity against wood-rotting fungi. These compounds have obvious insecticidal effects on termites. They also exhibited potent acaricidal activity against mites. The above-mentioned features suggest that Konjiki-do, a well known national treasure, one of the buildings in Chuson-ji Temple of Iwate Prefecture, Japan, which was built of wood from the tree containing these five compounds, was kept from harm against noxious insects and wood-rotting fungi for a long time of about 840 years, until it was extensively repaired in 1962. In addition to Konjiki-do, there are some old famous Buddhist temples and Shinto shrines using Aomori Hiba. From the results, it was found that Aomori Hiba (Hinokiasunaro) is excellent for use as building materials.
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Jianlin Y, Yaxian Y, Renao G. Raman spectroscopic studies on tropolone complexes with La, Nd, Sm, Yb. Spectrochim Acta A Mol Biomol Spectrosc 2006; 64:1072-6. [PMID: 16458049 DOI: 10.1016/j.saa.2005.09.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2005] [Accepted: 09/16/2005] [Indexed: 05/06/2023]
Abstract
The complexes of tropolone (HL) with different lanthanide metals of lanthanum (La), neodymium (Nd), samarium (Sm), ytterbium (Yb) have been prepared respectively in the non-aqueous solution by the direct electrochemical oxidation of sacrificial metal anodes, and characterized by normal Raman spectroscopy. By comparing the spectra of the ligands and their complexes, the stretching vibrational band of OH disappeared in complexes, and the frequencies shifts of some relevant bands were observed, particularly for the stretching vibration of CO. In the low frequency region, new metal ion sensitive bands at 400-700 cm(-1) were observed, which could be assigned to the stretching vibrational mode of the bonding of lanthanide with oxygen. The stretching vibration of lanthanide-oxygen of tropolonate complexes showed a metal ion sensitivity. All the obvious change in spectral feature of Raman spectra revealed that CO and OH were coordinated with the center metal ions through oxygen atoms. Based on Raman results, the structures of the above complexes were proposed.
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Affiliation(s)
- Yao Jianlin
- Department of Chemistry, Suzhou University, 1 Shizi Street, Suzhou 215006, China.
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35
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Abstract
The ground electronic state (X 1A1) of tropolone has been examined theoretically by exploiting extensive sets of basis functions [e.g., 6-311++G(d,p) and aug-cc-pVDZ] in conjunction with the high levels of electron correlation made possible by density functional (DFT/B3LYP), Moller-Plesset perturbation (MP2), and coupled-cluster [CCSD and CCSD(T)] methods. Unconstrained MP2 and CCSD optimization procedures performed with the reference 6-311++G(d,p) basis predict a slightly nonplanar equilibrium structure characterized by a small barrier to skeletal inversion (< or =10 cm(-1) magnitude). Complementary harmonic frequency analyses have shown this nonplanarity to be a computational artifact arising from adversely tuned carbon d-orbital exponents embodied in the standard definitions of several Pople-type basis sets. Correlation-consistent bases such as Dunning's aug-cc-pVDZ are less susceptible to these effects and were employed to confirm that the X 1A1 hypersurface supports a rigorously planar global minimum. The fully optimized geometries and vibrational force fields obtained by applying potent coupled-cluster schemes to the relaxed-equilibrium (Cs) and transition-state (C2v) conformers of tropolone afford a trenchant glimpse of the key features that mediate intramolecular hydron exchange in this model system. By incorporating perturbative triples corrections at the substantial CCSD(T) level of theory, an interoxygen distance of r(O...O)=2.528 A was determined for the minimum-energy configuration, with the accompanying proton-transfer reaction being hindered by a barrier of 2557.0 cm(-1) height. The potential energy landscape in tropolone, as well as the nature of the attendant hydron migration process, is discussed within the framework of the encompassing G4 molecular symmetry group.
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Affiliation(s)
- Lori A Burns
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, USA
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Kurihara T, Mine H, Satoh Y, Wakabayashi H, Motohashi N, Sakagami H. Relationship between electronic structure and cytotoxic activity of tropolones. In Vivo 2006; 20:391-5. [PMID: 16724677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
A structure-activity relationship of the cytotoxic activity of tropolone derivatives was discussed, using theoretical calculations. In order to clearly divide the tropolones into two structurally analogous groups, four different dipole moments (muG, muESP-G, muW and muESP-W) and heats of formation (deltaHf) of the tropolones [1-21] were calculated in the gas-phase and in water-solution by the conductor-like screening model/parametric method 3 (COSMO/PM3). The cytotoxic activities of the tropolones and 2-methoxytropones seem to be related to the three QSAR parameters deltadeltaHf, HOMO energy (EH) and muw. The cytotoxic activity of the five tropone derivatives [17-21] might depend on the QSAR parameters deltadeltaHf, LUMO energy (EL) and muESP-G. The results of the present study suggest the applicability of theoretical calculations such as frontier molecular orbital, dipole moments and deltadeltaHf in the prediction of the cytotoxic activity of tropolone derivatives.
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Affiliation(s)
- Teruo Kurihara
- Department of Chemistry, Faculty of Science, Josai University, 1-1 Keyakidai, Sakado, Saitama 350-0295, Japan.
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37
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Affiliation(s)
- N E Basova
- Sechenov Institute of Evolutionary Physiology and Biochemistry Russian Academy of Sciences, pr. Morisa Toreza 44, St. Petersburg, 194223 Russia
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Zhang J, Robinson D, Salmon P. A novel function for selenium in biological system: Selenite as a highly effective iron carrier for Chinese hamster ovary cell growth and monoclonal antibody production. Biotechnol Bioeng 2006; 95:1188-97. [PMID: 16937407 DOI: 10.1002/bit.21081] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
As the market for biopharmaceuticals especially monoclonal antibodies (MAbs) rapidly grows, their manufacturing methods are coming under increasing regulatory scrutiny, particularly due to concerns about the potential introduction of adventitious agents from animal-sourced components in the media used for their production in mammalian cell culture. Chinese hamster ovary (CHO) cells are by far the most commonly used production vehicles for these recombinant glycoproteins. In developing animal-component free media for CHO and other mammalian cell lines, the iron-transporter function of serum or human/bovine transferrin is usually replaced by certain organic or inorganic chelators capable of delivering iron for cell respiration and metabolism, but few of them are sufficiently effective. Selenium is a well-known essential trace element (TE) for cell growth and development, and its positive role in biological system includes detoxification of free radicals by activating glutathione peroxidase. In cell culture, selenium in the form of selenite can help cells to detoxify the medium thus protect them from oxidative damage. In this presentation, we describe the discovery and application of a novel function of selenite, that is, as a highly effective carrier to deliver iron for cell growth and function. In our in-house-developed animal protein-free (APF) medium for CHO cells, using an iron-selenite compound to replace the well-established tropolone delivery system for iron led to comparable or better cell growth and antibody production. A high cell density of >10 x 10(6) viable cells/mL and excellent antibody titer of approximately 3 g/L were achieved in 14-day fed-batch cultures in shake flasks, followed by successful scale-up to stirred bioreactors. The preparation of the commercially unavailable iron-selenite compound from respective ions, and its effectiveness in cell-culture performance, were dependent on reaction time, substrates, and other conditions.
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Affiliation(s)
- Jinyou Zhang
- Bioprocess R&D, Merck & Co., Inc., Rahway, New Jersey 07065, USA.
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Abstract
Computational studies of 12 64-electron homologues and isomers of tropolone in the S(0) electronic ground state are reported. Three minimum-energy structures, tropolone (Tp), 5-azatropolone (5Azt), and 5-H-5-azatropolonium (5AztH(+)), have an internal H-bond and planar C(s)) geometry, and three, tropolonate (TpO(-)), 5-azatropolonate (5AzO(-)), and 1-H-azepine-4,5-dione (45Di), lack the H-bond and have twisted C(2) geometry. All 6 substances have an equal double-minimum potential energy surface and a saddle point with planar C(2)(v) geometry. The energy for the gas-phase isomerization reaction 45Di --> 5Azt is near +4 kJ mol(-1) at the MP4(SDQ)/6-311++G(df,pd)//MP2/6-311++G(df,pd) (energy//geometry) theoretical level and around -20 kJ mol(-1) at lower theoretical levels. The dipole moments computed for 45Di and 5Azt are 9.6 and 2.1 D, respectively, and this large difference contributes to MO-computed free energies of solvation that strongly favor--as experimentally observed--45Di over 5Azt in chloroform solvent. The MO-computed energy for the gas-phase protonation reaction 45Di + H(+) --> 5AztH(+) is -956.4 kJ mol(-1), leading to 926.8 kJ mol(-1) as the estimated proton affinity for 45Di at 298 K and 1 atm. The intramolecular dynamical properties predicted for 5Azt and 5AztH(+) parallel those observed for tropolone. They are therefore expected to exhibit spectral tunneling doublets. Once they are synthesized, they should contribute importantly to the understanding of multidimensional intramolecular H transfer and dynamical coupling processes.
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Affiliation(s)
- Richard L Redington
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, USA
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Seganish WM, Handy CJ, DeShong P. Efforts Directed toward the Synthesis of Colchicine: Application of Palladium-Catalyzed Siloxane Cross-Coupling Methodology. J Org Chem 2005; 70:8948-55. [PMID: 16238332 DOI: 10.1021/jo051636h] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[reaction: see text] Colchicine is an important and synthetically challenging natural product. The key synthetic step in this approach to the synthesis of colchicine involved a palladium-catalyzed cross-coupling reaction between 5-bromotropolone (4) and an aryl siloxane to form the aryl-tropolone bond. The coupling of a variety of highly functionalized aryl siloxane derivatives was investigated and optimized coupling conditions were developed. It was discovered that a palladium catalyst with a high degree of phosphine ligand coordination (5 equiv of phosphine/mol Pd) was necessary to efficiently couple aryl siloxanes with 5-bromotropolone (4). In addition, the coupling approach has provided a direct comparison between siloxane and boronic acid coupling technologies that demonstrated that aryl siloxanes and boronic acids produce similar yields of highly functionalized biaryl products.
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Affiliation(s)
- W Michael Seganish
- Department of Chemistry and Biochemistry, University of Maryland, College Park, 20742, USA
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41
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Abstract
Antiplasmodial and cytotoxicity testing of five highly oxygenated natural products (6R,12R,14R-colletoketol, 6R,11R,12R,14R-colletoketodiol, dihydrobotrydial, pycnidione, and 3R,4S-hydroxymellein), all derived from fungi of marine origin, showed one of them, pycnidione, to have activities against three different strains of Plasmodium falciparum in the sub-micromolar (microM) range. Although the mean selectivity index of 1 for the observed antiplasmodial activity of 4 is low, pycnidione's usefulness as a potential lead structure should not be ignored.
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Affiliation(s)
- Anthony D Wright
- Australian Institute of Marine Science, Townsville MC, Queensland 4810, Australia.
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42
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Jin Y, Kong H, Stodilka RZ, Wells RG, Zabel P, Merrifield PA, Sykes J, Prato FS. Determining the minimum number of detectable cardiac-transplanted 111In-tropolone-labelled bone-marrow-derived mesenchymal stem cells by SPECT. Phys Med Biol 2005; 50:4445-55. [PMID: 16177481 DOI: 10.1088/0031-9155/50/19/001] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In this work, we determined the minimum number of detectable 111In-tropolone-labelled bone-marrow-derived stem cells from the maximum activity per cell which did not affect viability, proliferation and differentiation, and the minimum detectable activity (MDA) of 111In by SPECT. Canine bone marrow mesenchymal cells were isolated, cultured and expanded. A number of samples, each containing 5x10(6) cells, were labelled with 111In-tropolone from 0.1 to 18 MBq, and cell viability was measured afterwards for each sample for 2 weeks. To determine the MDA, the anthropomorphic torso phantom (DataSpectrum Corporation, Hillsborough, NC) was used. A point source of 202 kBq 111In was placed on the surface of the heart compartment, and the phantom and all compartments were then filled with water. Three 111In SPECT scans (duration: 16, 32 and 64 min; parameters: 128x128 matrix with 128 projections over 360 degrees) were acquired every three days until the 111In radioactivity decayed to undetectable quantities. 111In SPECT images were reconstructed using OSEM with and without background, scatter or attenuation corrections. Contrast-to-noise ratio (CNR) in the reconstructed image was calculated, and MDA was set equal to the 111In activity corresponding to a CNR of 4. The cells had 100% viability when incubated with no more than 0.9 MBq of 111In (80% labelling efficiency), which corresponded to 0.14 Bq per cell. Background correction improved the detection limits for 111In-tropolone-labelled cells. The MDAs for 16, 32 and 64 min scans with background correction were observed to be 1.4 kBq, 700 Bq and 400 Bq, which implies that, in the case where the location of the transplantation is known and fixed, as few as 10,000, 5000 and 2900 cells respectively can be detected.
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Affiliation(s)
- Yuan Jin
- Imaging Program, Lawson Health Research Institute, and Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada.
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43
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Abstract
Infrared-absorption profiles observed for vibrational transitions of gaseous tropolone often show sharp Q branch peaks, some of them ultranarrow spikes, indicative of the band origins for vibrational state-specific spectral tunneling doublets. In this work oxygen isotope effects for two CH wagging fundamentals, the COH torsion fundamental, and the skeletal contortion fundamental are reported. They allow considerations to be given: (1) oxygen isotope effects on the vibrational frequencies and state-specific tunneling splittings; (2) the asymmetry offset of the potential-energy minima for 16O and 18O tropolone; and (3) additional details concerning previously proposed high J rotation-contortion resonances in the contortional fundamental. The new results help to characterize the skeletal contortion fundamental and support the joint participation of skeletal tunneling with H tunneling in the vibrational state-specific tautomerization processes of tropolone in its ground electronic state.
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Affiliation(s)
- Richard L Redington
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, USA.
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Lambert JD, Chen D, Wang CY, Ai N, Sang S, Ho CT, Welsh WJ, Yang CS. Benzotropolone inhibitors of estradiol methylation: kinetics and in silico modeling studies. Bioorg Med Chem 2005; 13:2501-7. [PMID: 15755652 DOI: 10.1016/j.bmc.2005.01.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2004] [Revised: 01/06/2005] [Accepted: 01/21/2005] [Indexed: 10/25/2022]
Abstract
Natural and synthetic benzotropolone compounds were assessed in vitro for their ability to inhibit hydroxyestradiol methylation by catechol-O-methyltransferase (COMT). The compounds were also modeled in silico with a homology model of human COMT. Purpurogallin (1), purpurogallin carboxylic acid (2), and theaflavin-3,3'-digallate (6) were the most potent inhibitors of 2-hydroxy and 4-hydroxyestradiol methylation (IC(50) 0.22-0.50microM). Compounds 1 and 6 decreased the V(max) and increased the K(m) of COMT, indicating a mixed-type inhibition. Compounds 1 and 2 bound to COMT by inserting the six-membered ring of the benzotropolone into the active site. Decreased acidity of the hydroxyl groups on this ring or increased bulkiness reduced potency. Compound 6 bound by inserting the galloyl ester into the active site, which allowed the compound to overcome increased bulkiness and resulted in restored potency. Further studies are needed to determine the impact in vivo of COMT inhibition by these compounds.
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Affiliation(s)
- Joshua D Lambert
- Department of Chemical Biology Rutgers, Ernest Mario School of Pharmacy, The State University of New Jersey, 164 Frelinghuysen Rd, Piscataway, NJ 08854, USA
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Budihas SR, Gorshkova I, Gaidamakov S, Wamiru A, Bona MK, Parniak MA, Crouch RJ, McMahon JB, Beutler JA, Le Grice SFJ. Selective inhibition of HIV-1 reverse transcriptase-associated ribonuclease H activity by hydroxylated tropolones. Nucleic Acids Res 2005; 33:1249-56. [PMID: 15741178 PMCID: PMC552956 DOI: 10.1093/nar/gki268] [Citation(s) in RCA: 156] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
High-throughput screening of a National Cancer Institute library of pure natural products identified the hydroxylated tropolone derivatives beta-thujaplicinol (2,7-dihydroxy-4-1(methylethyl)-2,4,6-cycloheptatrien-1-one) and manicol (1,2,3,4-tetrahydro-5-7-dihydroxy-9-methyl-2-(1-methylethenyl)-6H-benzocyclohepten-6-one) as potent and selective inhibitors of the ribonuclease H (RNase H) activity of human immunodeficiency virus-type 1 reverse transcriptase (HIV-1 RT). beta-Thujaplicinol inhibited HIV-1 RNase H in vitro with an IC50 of 0.2 microM, while the IC50 for Escherichia coli and human RNases H was 50 microM and 5.7 microM, respectively. In contrast, the related tropolone analog beta-thujaplicin (2-hydroxy-4-(methylethyl)-2,4,6-cycloheptatrien-1-one), which lacks the 7-OH group of the heptatriene ring, was inactive, while manicol, which possesses a 7-OH group, inhibited HIV-1 and E.coli RNases H with IC50 = 1.5 microM and 40 microM, respectively. Such a result highlights the importance of the 2,7-dihydroxy function of these tropolone analogs, possibly through a role in metal chelation at the RNase H active site. Inhibition of HIV-2 RT-associated RNase H indirectly indicates that these compounds do not occupy the nonnucleoside inhibitor-binding pocket in the vicinity of the DNA polymerase domain. Both beta-thujaplicinol and manicol failed to inhibit DNA-dependent DNA polymerase activity of HIV-1 RT at a concentration of 50 microM, suggesting that they are specific for the C-terminal RNase H domain, while surface plasmon resonance studies indicated that the inhibition was not due to intercalation of the analog into the nucleic acid substrate. Finally, we have demonstrated synergy between beta-thujaplicinol and calanolide A, a nonnucleoside inhibitor of HIV-1 RT, raising the possibility that both enzymatic activities of HIV-1 RT can be simultaneously targeted.
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Affiliation(s)
| | - Inna Gorshkova
- Protein Biophysics Resource, Division of Bioengineering and Physical Sciences, National Institutes of HealthBethesda, MD 20892, USA
| | - Sergei Gaidamakov
- Laboratory of Molecular Genetics, National Institute of Child Health and Human DevelopmentBethesda, MD 20892, USA
| | - Antony Wamiru
- Molecular Targets Development Program, National Cancer Institute at FrederickFrederick, MD 21702, USA
- SAIC-Frederick, FrederickMD 21702, USA
| | | | - Michael A. Parniak
- Division of Infectious Diseases, School of Medicine, University of PittsburghPittsburgh, PA 15213, USA
| | - Robert J. Crouch
- Laboratory of Molecular Genetics, National Institute of Child Health and Human DevelopmentBethesda, MD 20892, USA
| | - James B. McMahon
- Molecular Targets Development Program, National Cancer Institute at FrederickFrederick, MD 21702, USA
| | - John A. Beutler
- Molecular Targets Development Program, National Cancer Institute at FrederickFrederick, MD 21702, USA
| | - Stuart F. J. Le Grice
- To whom correspondence should be addressed. Tel: +1 301 846 5256; Fax: +1 301 846 6013;
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Affiliation(s)
- Hiroshi Ushiyama
- Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 153-8902, Tokyo, Japan.
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Morita Y, Matsumura E, Okabe T, Fukui T, Shibata M, Sugiura M, Ohe T, Tsujibo H, Ishida N, Inamori Y. Biological activity of alpha-thujaplicin, the isomer of hinokitiol. Biol Pharm Bull 2005; 27:899-902. [PMID: 15187442 DOI: 10.1248/bpb.27.899] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
alpha-Thujaplicin, a minor component of Aomori Hiba (Thujopsis dolabrata SIEB. et ZUCC. var. hondai MAKINO), showed rather strong antifungal activity against seven kinds of plant-pathogenic fungi, their minimum inhibitory concentrations (MICs) being in the range of 12.0-50.0 microg/ml. alpha-Thujaplicin and hinokitiol (the major component of Aomori Hiba) also showed clear antibacterial activity against Legionella pneumophila SG 1 and L. pneumophila SG 3, and their MICs are in the range of 6.25-50 microg/ml. This compound showed strong insecticidal activity against Reticulitermes speratus [50%-lethal concentration (LC(50)): 0.02 g/m(2)], and it also had clear acaricidal activity against Dermatophagoides farinae (LC(50): 0.66 g/m(2)). At 24 h after treatment, alpha-thujaplicin at 0.63 microg/ml inhibited the cell growth of murine P388 lymphocytic leukemia by 78%, and its cytotoxic activity at a concentration higher than 0.63 microg/ml was as high as that of vincristine, used as a positive control. On the other hand, the cytotoxic effect of alpha-thujaplicin at 0.63 microg/ml was weaker than that of vinblastine. In this respect, the strong cytotoxic effect of alpha-thujaplicin on murine P388 lymphocytic leukemia cell line should be emphasized, considering that it has recently been found to be low in toxicity to mice.
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Abstract
Synthesis of 4-aminotropones through a cyclization-ring expansion process occurs in a single step and with excellent yields from 4-amino-2,5-cyclohexadienones (p-quinamines) bearing a 4-sulfinyl or sulfonyl methyl group.
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Affiliation(s)
- M Carmen Carreño
- Dpto. de Química Orgánica (C-I), Universidad Autónoma, Cantoblanco, 28049-Madrid, Spain.
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Kim DS, Kim SY, Park SH, Choi YG, Kwon SB, Kim MK, Na JI, Youn SW, Park KC. Inhibitory Effects of 4-n-Butylresorcinol on Tyrosinase Activity and Melanin Synthesis. Biol Pharm Bull 2005; 28:2216-9. [PMID: 16327152 DOI: 10.1248/bpb.28.2216] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In this study, we investigated the effects of 4-n-butylresorcinol on melanogenesis in a spontaneously immortalized mouse melanocyte cell line, Mel-Ab. Our results show that 4-n-butylresorcinol significantly inhibits melanin synthesis in a concentration-dependent manner. In addition, it was also found to inhibit the activity of tyrosinase, the rate-limiting melanogenic enzyme. Several reports have indicated that the activation of extracellular signal-regulated kinase (ERK) or of Akt reduces melanin synthesis via microphthalmia-associated transcription factor (MITF) down-regulation. Accordingly, we examined the effects of 4-n-butylresorcinol on the ERK and Akt signaling pathways. 4-n-Butylresorcinol did not induce ERK, Akt activation, or MITF degradation, and had no effect on cAMP response element binding protein (CREB) phosphorylation, which stimulates MITF expression. In contrast, 4-n-butylresorcinol strongly reduced tyrosinase activity in a cell-free system. Moreover, 4-n-butylresorcinol showed an additive effect in combination with hinokitiol, which reduces MITF expression. These results show that the hypopigmentary effect of 4-n-butylresorcinol results from its direct inhibition of tyrosinase.
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Affiliation(s)
- Dong-Seok Kim
- Department of Dermatology, Seoul National University College of Medicine, Chongno-Gu, Korea
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Abstract
The alkaloid spectra of Datura innoxia plants grown in Egypt and Bulgaria were investigated by GC-MS. Thirty-eight alkaloids were detected in the roots, leaves and fruits of the plants. Five new alkaloids for D. innoxia are reported. Alkaloid spectra of Egyptian and Bulgarian plants differ significantly in respect to their alkaloid composition and main alkaloids accumulated in the plant organs.
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Affiliation(s)
- Strahil Berkov
- Department of Applied Botany, Institute of Botany, Bulgarian Academy of Sciences, 23 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria.
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