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Khong QT, Smith EA, Wendt KL, Dalilian M, Goncharova EI, Brownell I, Cichewicz RH, Henrich CJ, Beutler JA, O'Keefe BR, Du L. Chemoreactive 2,5-Diketopiperazines from a Penicillium sp., Structure Revision of Reported Analogues and Proposed Facile Transformation Pathways. JOURNAL OF NATURAL PRODUCTS 2024; 87:1826-1837. [PMID: 38995621 DOI: 10.1021/acs.jnatprod.4c00478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/13/2024]
Abstract
Merkel cell carcinoma (MCC) is a rare and aggressive cutaneous cancer. Two new prenylated indole 2,5-diketopiperazine alkaloids, brevianamides E1 (1) and E2 (2), were isolated from a Penicillium fungus. Both compounds showed moderate cytotoxic activity against select MCC cell lines (i.e., MCC13, MKL-1, UISO, and WaGa) in the low micromolar range. The relative and absolute configurations of 1 and 2 were determined by combined approaches, including NOESY spectroscopy, DFT ECD and DP4 plus calculations, and Marfey's reaction. Literature research and the comparison of NMR and ECD data led to the structure revision of three previously reported natural analogues, notoamides K and P and asperversiamide L. The structurally unstable 1 and 2 underwent steady interconversion under neutral aqueous conditions. Investigation of the degradation of 2 in acidic methanol solutions led to the identification of a new methoxylated derivative (6) and two new ring-opened products (7 and 8) with the rearranged, elongated, 4-methylpent-3-ene side chain. The facile transformation of 2 to 7 and 8 was promoted by the intrinsic impurity (i.e., formaldehyde) of HPLC-grade methanol through the aza-Cope rearrangement.
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Affiliation(s)
- Quan T Khong
- Molecular Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Emily A Smith
- Molecular Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
- Leidos Biomedical Res., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Karen L Wendt
- Natural Products Discovery Group, Institute for Natural Products Applications and Research Technologies, Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - Masoumeh Dalilian
- Molecular Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
- Leidos Biomedical Res., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Ekaterina I Goncharova
- Molecular Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
- Advanced Biomedical Computational Science, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Isaac Brownell
- Dermatology Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, Maryland 20892, United States
| | - Robert H Cichewicz
- Natural Products Discovery Group, Institute for Natural Products Applications and Research Technologies, Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - Curtis J Henrich
- Molecular Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
- Leidos Biomedical Res., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - John A Beutler
- Molecular Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Barry R O'Keefe
- Molecular Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
- Natural Products Branch, Developmental Therapeutics Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Lin Du
- Molecular Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
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2
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Tuncel ST, Demir I, Erdem SS, Dogan I. Stable hemiaminals from axially chiral pyridine compounds. Chirality 2023; 35:365-375. [PMID: 36762682 DOI: 10.1002/chir.23545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 01/19/2023] [Accepted: 01/29/2023] [Indexed: 02/11/2023]
Abstract
In this study, we have synthesized a series of 3-(pyridin-2-yl)-2-(pyridin-2-ylimino)thiazolidin-4-ol derivatives regioselectively from 2-iminothiazolidin-4-ones using LiAlH4 at room temperature. Due to the presence of the restricted rotation around the N3-Caryl single bond, the formation of M/P isomers was observed. The OH group of the hemiaminal was found to orient itself on the same side with pyridyl nitrogen during this restricted rotation to form an intramolecular hydrogen bond, which was demonstrated by the computational DFT study. This orientation presumably inhibited the occurrence of dehydration and stabilized the molecule.
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Affiliation(s)
| | - Ilke Demir
- Department of Chemistry, Marmara University, Istanbul, Turkey
| | | | - Ilknur Dogan
- Department of Chemistry, Bogazici University, Istanbul, Turkey
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Mubeena A, Nagarajaiah H, Pulakuntla S, Damodara Reddy V, Madhusudana Reddy MB. Synthesis and Molecular Docking Studies of a Series of Amino-Pyrimidines as Possible Anti-Cancer Agents. Polycycl Aromat Compd 2023. [DOI: 10.1080/10406638.2023.2174994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Affiliation(s)
- Ameerjan Mubeena
- Department of Chemistry, REVA University, Bangalore, Karnataka, India
| | | | - Swetha Pulakuntla
- Department of Biochemistry, School of Applied Sciences, REVA University, Bangalore, Karnataka, India
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4
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Kotnik T, Žerjav G, Pintar A, Žagar E, Kovačič S. Azine- and imine-linked conjugated polyHIPEs through Schiff-base condensation reaction. Polym Chem 2022. [DOI: 10.1039/d1py01467f] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A new alternative synthetic route to the transition-metal free π-conjugated polyHIPEs is reported, which combines the Schiff-base condensation reaction and an emulsion-templating technology.
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Affiliation(s)
- Tomaž Kotnik
- National Institute of Chemistry, Department of Polymer Chemistry and Technology, Hajdrihova 19, SI-1001 Ljubljana, Slovenia
| | - Gregor Žerjav
- National Institute of Chemistry, Department of Inorganic Chemistry and Technology, Hajdrihova 19, SI-1001 Ljubljana, Slovenia
| | - Albin Pintar
- National Institute of Chemistry, Department of Inorganic Chemistry and Technology, Hajdrihova 19, SI-1001 Ljubljana, Slovenia
| | - Ema Žagar
- National Institute of Chemistry, Department of Polymer Chemistry and Technology, Hajdrihova 19, SI-1001 Ljubljana, Slovenia
| | - Sebastijan Kovačič
- National Institute of Chemistry, Department of Polymer Chemistry and Technology, Hajdrihova 19, SI-1001 Ljubljana, Slovenia
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The Advantage of Automatic Peer-Reviewing of 13C-NMR Reference Data Using the CSEARCH-Protocol. Molecules 2021; 26:molecules26113413. [PMID: 34200052 PMCID: PMC8200238 DOI: 10.3390/molecules26113413] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 05/25/2021] [Accepted: 05/31/2021] [Indexed: 11/23/2022] Open
Abstract
A systematic investigation of the experimental 13C-NMR spectra published in Molecules during the period of 1996 to 2015 with respect to their quality using CSEARCH-technology is described. It is shown that the systematic application of the CSEARCH-Robot-Referee during the peer-reviewing process prohibits at least the most trivial assignment errors and wrong structure proposals. In many cases, the correction of the assignments/chemical shift values is possible by manual inspection of the published tables; in certain cases, reprocessing of the original experimental data might help to clarify the situation, showing the urgent need for a public domain repository. A comparison of the significant key numbers derived for Molecules against those of other important journals in the field of natural product chemistry shows a quite similar level of quality for all publishers responsible for the six journals under investigation. From the results of this study, general rules for data handling, data storage, and manuscript preparation can be derived, helping to increase the quality of published NMR-data and making these data available as validated reference material.
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Gamboa Marin OJ, Hussain N, Ravicoularamin G, Ameur N, Gormand P, Sauvageau J, Gauthier C. Total Synthesis of 6-Amino-2,6-dideoxy-α-Kdo from d-Mannose. Org Lett 2020; 22:5783-5788. [DOI: 10.1021/acs.orglett.0c01847] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Oscar Javier Gamboa Marin
- Centre Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), 531, boul. des Prairies, Laval, Québec, Canada H7V 1B7
| | - Nazar Hussain
- Centre Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), 531, boul. des Prairies, Laval, Québec, Canada H7V 1B7
| | - Gokulakrishnan Ravicoularamin
- Centre Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), 531, boul. des Prairies, Laval, Québec, Canada H7V 1B7
| | - Nassima Ameur
- Centre Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), 531, boul. des Prairies, Laval, Québec, Canada H7V 1B7
| | - Paul Gormand
- Centre Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), 531, boul. des Prairies, Laval, Québec, Canada H7V 1B7
| | - Janelle Sauvageau
- Centre Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), 531, boul. des Prairies, Laval, Québec, Canada H7V 1B7
- National Research Council Canada (NRC), 100 Sussex Drive, Ottawa, Ontario, Canada K1A 0R6
| | - Charles Gauthier
- Centre Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), 531, boul. des Prairies, Laval, Québec, Canada H7V 1B7
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Sharma V, Mehmood A, Janesko BG, Simanek EE. TEMPORARY REMOVAL: A hydrogen bond and strong electron withdrawing group lead to the formation of surprisingly stable, cyclic hemiaminals. Tetrahedron Lett 2019. [DOI: 10.1016/j.tetlet.2019.151334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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8
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Tinson RA, Hughes DL, Ward L, Stephenson GR. Unusual Nucleophilic Addition of Grignard Reagents in the Synthesis of 4-Amino-pyrimidines. ACS OMEGA 2018; 3:8937-8944. [PMID: 31459026 PMCID: PMC6644423 DOI: 10.1021/acsomega.8b01137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 07/18/2018] [Indexed: 06/10/2023]
Abstract
Pyrimidines have always received considerable attention because of their importance in synthesis and elucidation of biochemical roles, in particular that of vitamin B1. Herein, we describe a reaction pathway in a Grignard reagent-based synthesis of substituted pyrimidines. A general synthesis of α-keto-2-methyl-4-amino pyrimidines and their C6-substituted analogues from 4-amino-5-cyano-2-methylpyrimidine is reported. The presence of the nitrile substituent in the starting material also results in an unusual reaction pathway leading to C6-substituted 1,2-dihydropyrimidines. Grignard reagents that give normal pyrimidine products under standard reaction conditions can be switched to give dihydropyrimidines by holding the reaction at 0 °C before quenching.
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Mielcarek A, Wiśniewska A, Dołęga A. Unassisted formation of hemiaminal ether from 4-aminopyridine and o-vanillin - experimental and theoretical study. Struct Chem 2018. [DOI: 10.1007/s11224-018-1105-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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10
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Bikas R, Ajormal F, Emami M, Noshiranzadeh N, Kozakiewicz A. Catalytic oxidation of benzyl alcohols by new Cu(II) complexes of 1,3-oxazolidine based ligand obtained from a solvent free reaction. Inorganica Chim Acta 2018. [DOI: 10.1016/j.ica.2018.03.038] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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