1
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Mari M, Boniburini M, Tosato M, Zanni F, Bonini F, Faglioni F, Cuoghi L, Belluti S, Imbriano C, Asti M, Ferrari E. Bridging pyrimidine hemicurcumin and Cisplatin: Synthesis, coordination chemistry, and in vitro activity assessment of a novel Pt(II) complex. J Inorg Biochem 2024; 260:112702. [PMID: 39163714 DOI: 10.1016/j.jinorgbio.2024.112702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2024] [Revised: 08/05/2024] [Accepted: 08/15/2024] [Indexed: 08/22/2024]
Abstract
In the upcoming decades, the incidence and mortality rates of cancer are expected to rise globally, with colorectal and prostate cancers among the most prevalent types. Despite advancements in molecular targeted therapy, platinum-based chemotherapies remain the cornerstone of treatment, especially for colorectal and prostate cancer, with oxaliplatin and cisplatin being extremely effective due to their DNA-targeting capabilities. In our pursuit of new platinum-based chemotherapeutics that are potentially less toxic and more effective, we have explored the combination of the Pt-binding groups of the diaminocyclohexane ring used in oxaliplatin, with the stable amino-pyrimidine hemicurcumin moiety. This new derivative exhibit improved stability in physiological conditions and increased solubility in aqueous media, demonstrating promising effects on cell proliferation of both colorectal and prostate cells. We report herein the complete synthesis and chemical characterization in solution of the new derivative [(1R,2R)-N1-(3-(4-((E)-2-(2-Amino-6-methylpyrimidin-4-yl)vinyl)-2-methoxyphenoxy) propyl) cyclohexane-1,2-diamine] (MPYD). Our analysis includes an examination of its acid-base equilibria, speciation and stability in physiological conditions. The synthesis and in situ formation of Pt(II) complexes were investigated by nuclear magnetic resonance spectroscopy, while density functional theory calculations were employed to elucidate the chemical structure in solution. Results on the biological activity were obtained through cell viability assays on different colorectal and prostate cell lines (HCT116, HT29, PC3 and LNCaP).
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Affiliation(s)
- Matteo Mari
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, via Campi, 103, 41125 Modena, Italy
| | - Matteo Boniburini
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, via Campi, 103, 41125 Modena, Italy
| | - Marianna Tosato
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, via Campi, 103, 41125 Modena, Italy; Radiopharmaceutical Chemistry Section, Nuclear Medicine Unit, Azienda USL-IRCCS Reggio Emilia, via Amendola 2, 42122 Reggio Emilia, Italy
| | - Francesca Zanni
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, via Campi, 103, 41125 Modena, Italy
| | - Filippo Bonini
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, via Campi, 103, 41125 Modena, Italy
| | - Francesco Faglioni
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, via Campi, 103, 41125 Modena, Italy
| | - Laura Cuoghi
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi, 213/d, 41125 Modena, Italy.
| | - Silvia Belluti
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi, 213/d, 41125 Modena, Italy.
| | - Carol Imbriano
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi, 213/d, 41125 Modena, Italy.
| | - Mattia Asti
- Radiopharmaceutical Chemistry Section, Nuclear Medicine Unit, Azienda USL-IRCCS Reggio Emilia, via Amendola 2, 42122 Reggio Emilia, Italy.
| | - Erika Ferrari
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, via Campi, 103, 41125 Modena, Italy.
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2
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Gao Y, Frank M, Teusch N, Woschko D, Janiak C, Mándi A, Kurtán T, Hartmann R, Schiedlauske K, van Geelen L, Kalscheuer R, Kaiser J, Gertzen CGW, Gohlke H, Wang BG, Proksch P, Liu Z. Aplospojaveedins A-C, unusual sulfur-containing alkaloids produced by the endophytic fungus Aplosporella javeedii using OSMAC strategy. Front Microbiol 2024; 15:1458622. [PMID: 39397793 PMCID: PMC11466890 DOI: 10.3389/fmicb.2024.1458622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2024] [Accepted: 09/18/2024] [Indexed: 10/15/2024] Open
Abstract
Three sulfur-containing alkaloids aplospojaveedins A-C (1-3) with a hitherto undescribed carbon skeleton comprising octahy-dronaphthalene, α, β-unsaturated lactam and glycine-cysteine moieties were isolated from Aplosporella javeedii. Their structures were elucidated by 1D and 2D NMR spectroscopy, HR-MS, X-ray diffraction analysis, DFT-NMR and TDDFT-ECD calculations. A plausible biosynthetic pathway and putative targets are described. The blind docking suggested that 1-3 may have functional effects on several putative targets such as the GPCR cannabinoid receptor 2 or the integrin α5β1 complex.
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Affiliation(s)
- Ying Gao
- Key Laboratory of Study and Discovery of Small Targeted Molecules of Hunan Province, School of Medicine, Hunan Normal University, Changsha, China
- Institute of Pharmaceutical Biology and Biotechnology, Heinrich Heine University, Düsseldorf, Germany
| | - Marian Frank
- Institute of Pharmaceutical Biology and Biotechnology, Heinrich Heine University, Düsseldorf, Germany
| | - Nicole Teusch
- Institute of Pharmaceutical Biology and Biotechnology, Heinrich Heine University, Düsseldorf, Germany
| | - Dennis Woschko
- Institute of Inorganic and Structural Chemistry, Heinrich Heine University, Düsseldorf, Germany
| | - Christoph Janiak
- Institute of Inorganic and Structural Chemistry, Heinrich Heine University, Düsseldorf, Germany
| | - Attila Mándi
- Department of Organic Chemistry, University of Debrecen, Debrecen, Hungary
| | - Tibor Kurtán
- Department of Organic Chemistry, University of Debrecen, Debrecen, Hungary
| | - Rudolf Hartmann
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Katja Schiedlauske
- Institute of Pharmaceutical Biology and Biotechnology, Heinrich Heine University, Düsseldorf, Germany
| | - Lasse van Geelen
- Institute of Pharmaceutical Biology and Biotechnology, Heinrich Heine University, Düsseldorf, Germany
| | - Rainer Kalscheuer
- Institute of Pharmaceutical Biology and Biotechnology, Heinrich Heine University, Düsseldorf, Germany
| | - Jesko Kaiser
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University, Düsseldorf, Germany
| | - Christoph G. W. Gertzen
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University, Düsseldorf, Germany
| | - Holger Gohlke
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University, Düsseldorf, Germany
- Institute of Bio- and Geosciences (IBG-4: Bioinformatics), Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Bin-Gui Wang
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Peter Proksch
- Institute of Pharmaceutical Biology and Biotechnology, Heinrich Heine University, Düsseldorf, Germany
| | - Zhen Liu
- Key Laboratory of Study and Discovery of Small Targeted Molecules of Hunan Province, School of Medicine, Hunan Normal University, Changsha, China
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3
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Rangel-Grimaldo M, Earp CE, Raja HA, Wood JS, Mardiana L, Ho KL, Longcake A, Williamson RT, Palatinus L, Hall MJ, Probert MR, Oberlies NH. Wheldone Revisited: Structure Revision Via DFT-GIAO Chemical Shift Calculations, 1,1-HD-ADEQUATE NMR Spectroscopy, and X-ray Crystallography Studies. JOURNAL OF NATURAL PRODUCTS 2024; 87:2095-2100. [PMID: 39039966 PMCID: PMC11348420 DOI: 10.1021/acs.jnatprod.4c00649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Revised: 07/11/2024] [Accepted: 07/11/2024] [Indexed: 07/24/2024]
Abstract
Wheldone is a fungal metabolite isolated from the coculture of Aspergillus fischeri and Xylaria flabelliformis, displaying cytotoxic activity against breast, melanoma, and ovarian cancer cell lines. Initially, its structure was characterized as an unusual 5-methyl-bicyclo[5.4.0]undeca-3,5-diene scaffold with a 2-hydroxy-1-propanone side chain and a 3-(2-(1-hydroxyethyl)-2-methyl-2,5-dihydrofuran-3-yl)acrylic acid moiety. Upon further examination, minor inconsistencies in the data suggested the need for the structure to be revisited. Thus, the structure of wheldone has been revised using an orthogonal experimental-computational approach, which combines 1,1-HD-ADEQUATE NMR experiments, DFT-GIAO chemical shift calculations, and single-crystal X-ray diffraction (SCXRD) analysis of a semisynthetic p-bromobenzylamide derivative, formed via a Steglich-type reaction. The summation of these data now permits the unequivocal assignment of both the structure and absolute configuration of the natural product.
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Affiliation(s)
- Manuel Rangel-Grimaldo
- Department
of Chemistry and Biochemistry, University
of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Cody E. Earp
- Department
of Chemistry and Biochemistry, University
of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Huzefa A. Raja
- Department
of Chemistry and Biochemistry, University
of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Jared S. Wood
- Department
of Chemistry and Biochemistry, University
of North Carolina Wilmington, Wilmington, North Carolina 28409, United States
| | - Lina Mardiana
- Indicatrix
Crystallography Ltd, Newcastle University, Newcastle NE1 7RU, U.K.
- Chemistry
− School of Natural and Environmental Sciences, Newcastle University, Newcastle NE1 7RU, U.K.
- Department
of Chemistry, Universitas Indonesia, Depok, Jawa Barat 16424, Indonesia
| | - Kin Lok Ho
- Chemistry
− School of Natural and Environmental Sciences, Newcastle University, Newcastle NE1 7RU, U.K.
| | - Alexandra Longcake
- Chemistry
− School of Natural and Environmental Sciences, Newcastle University, Newcastle NE1 7RU, U.K.
| | - R. Thomas Williamson
- Department
of Chemistry and Biochemistry, University
of North Carolina Wilmington, Wilmington, North Carolina 28409, United States
| | - Lukáš Palatinus
- Department
of Structure Analysis, Institute of Physics
of the Czech Academy of Sciences, Na Slovance 2, Prague 18221, Czech Republic
| | - Michael J. Hall
- Chemistry
− School of Natural and Environmental Sciences, Newcastle University, Newcastle NE1 7RU, U.K.
| | - Michael R. Probert
- Chemistry
− School of Natural and Environmental Sciences, Newcastle University, Newcastle NE1 7RU, U.K.
| | - Nicholas H. Oberlies
- Department
of Chemistry and Biochemistry, University
of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
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4
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Wood JS, Tang J, Strangman WK, Williamson RT. Advanced Structure Analysis Reveals a Transient Portimine B Hydrate. JOURNAL OF NATURAL PRODUCTS 2024; 87:2120-2125. [PMID: 39054259 DOI: 10.1021/acs.jnatprod.4c00525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/27/2024]
Abstract
Portimine B was isolated from an extract derived from the dinoflagellate Vulcanodinium rugosum, a known producer of the closely related portimine A. Initial molecular characterization studies of portimine B suggested an open tetrahydrofuranyl ring isomer, contrary to the intact ring moiety found in portimine A. In 2023, the Baran lab synthesized both portimines A and B suggesting that both macrocyclic analogs contained the intact tetrahydrofuranyl ring. In this note, we utilize newly acquired NMR data, the i-HMBC NMR experiment, and advanced density functional theory calculations to define the structural divergence, originating from the presence of a transient hydrate.
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Affiliation(s)
- Jared S Wood
- Department of Chemistry and Biochemistry, University of North Carolina Wilmington, Wilmington, North Carolina 28409, United States
| | - Junchen Tang
- Department of Chemistry, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Wendy K Strangman
- Department of Chemistry and Biochemistry, University of North Carolina Wilmington, Wilmington, North Carolina 28409, United States
| | - R Thomas Williamson
- Department of Chemistry and Biochemistry, University of North Carolina Wilmington, Wilmington, North Carolina 28409, United States
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5
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Buedenbender L, Ageitos L, Lages MA, Platas-Iglesias C, Balado M, Lemos ML, Rodríguez J, Jiménez C. O-versus S-Metal Coordination of the Thiocarboxylate Group: An NMR Study of the Two Tautomeric Forms of the Ga(III)-Photoxenobactin E Complex. Inorg Chem 2024; 63:4176-4184. [PMID: 38387064 PMCID: PMC10915793 DOI: 10.1021/acs.inorgchem.3c04076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 01/30/2024] [Accepted: 02/02/2024] [Indexed: 02/24/2024]
Abstract
Photoxenobactin E (1) is a natural product with an unusual thiocarboxylic acid terminus recently isolated from an entomopathogenic bacterium. The biosynthetic gene cluster associated with photoxenobactin E, and other reported derivatives, is very similar to that of piscibactin, the siderophore responsible for the iron uptake among bacteria of the Vibrionaceae family, including potential human pathogens. Here, the reisolation of 1 from the fish pathogen Vibrio anguillarum RV22 cultured under iron deprivation, its ability to chelate Ga(III), and the full NMR spectroscopic characterization of the Ga(III)-photoxenobactin E complex are presented. Our results show that Ga(III)-photoxenobactin E in solution exists in a thiol-thione tautomeric equilibrium, where Ga(III) is coordinated through the sulfur (thiol form) or oxygen (thione form) atoms of the thiocarboxylate group. This report represents the first NMR study of the chemical exchange between the thiol and thione forms associated with thiocarboxylate-Ga(III) coordination, including the kinetics of the interconversion process associated with this tautomeric exchange. These findings show significant implications for ligand design as they illustrate the potential of the thiocarboxylate group as a versatile donor for hard metal ions such as Ga(III).
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Affiliation(s)
- Larissa Buedenbender
- CICA
− Centro Interdisciplinar de Química e Bioloxía
e Departamento de Química, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Spain
| | - Lucía Ageitos
- CICA
− Centro Interdisciplinar de Química e Bioloxía
e Departamento de Química, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Spain
| | - Marta A. Lages
- Departamento
de Microbiología y Parasitología, Instituto de Acuicultura, Universidade de Santiago de Compostela, 15782 Santiago
de Compostela, Spain
| | - Carlos Platas-Iglesias
- CICA
− Centro Interdisciplinar de Química e Bioloxía
e Departamento de Química, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Spain
| | - Miguel Balado
- Departamento
de Microbiología y Parasitología, Instituto de Acuicultura, Universidade de Santiago de Compostela, 15782 Santiago
de Compostela, Spain
| | - Manuel L. Lemos
- Departamento
de Microbiología y Parasitología, Instituto de Acuicultura, Universidade de Santiago de Compostela, 15782 Santiago
de Compostela, Spain
| | - Jaime Rodríguez
- CICA
− Centro Interdisciplinar de Química e Bioloxía
e Departamento de Química, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Spain
| | - Carlos Jiménez
- CICA
− Centro Interdisciplinar de Química e Bioloxía
e Departamento de Química, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Spain
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6
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Maste S, Sharma B, Pongratz T, Grabe B, Hiller W, Erlach MB, Kremer W, Kalbitzer HR, Marx D, Kast SM. The accuracy limit of chemical shift predictions for species in aqueous solution. Phys Chem Chem Phys 2024; 26:6386-6395. [PMID: 38315169 DOI: 10.1039/d3cp05471c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Interpreting NMR experiments benefits from first-principles predictions of chemical shifts. Reaching the accuracy limit of theory is relevant for unambiguous structural analysis and dissecting theoretical approximations. Since accurate chemical shift measurements are based on using internal reference compounds such as trimethylsilylpropanesulfonate (DSS), a detailed comparison of experimental with theoretical data requires simultaneous consideration of both target and reference species ensembles in the same solvent environment. Here we show that ab initio molecular dynamics simulations to generate liquid-state ensembles of target and reference compounds, including explicitly their short-range solvation environments and combined with quantum-mechanical solvation models, allows for predicting highly accurate 1H (∼0.1-0.5 ppm) and aliphatic 13C (∼1.5 ppm) chemical shifts for aqueous solutions of the model compounds trimethylamine N-oxide (TMAO) and N-methylacetamide (NMA), referenced to DSS without any system-specific adjustments. This encompasses the two peptide bond conformations of NMA identified by NMR. The results are used to derive a general-purpose guideline set for predictive NMR chemical shift calculations of NMA in the liquid state and to identify artifacts of force field models. Accurate predictions are only obtained if a sufficient number of explicit water molecules is included in the quantum-mechanical calculations, disproving a purely electrostatic model of the solvent effect on chemical shifts.
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Affiliation(s)
- Stefan Maste
- Fakultät für Chemie und Chemische Biologie, Technische Universität Dortmund, Otto-Hahn-Straße 4a, 44227 Dortmund, Germany.
| | - Bikramjit Sharma
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany.
| | - Tim Pongratz
- Fakultät für Chemie und Chemische Biologie, Technische Universität Dortmund, Otto-Hahn-Straße 4a, 44227 Dortmund, Germany.
| | - Bastian Grabe
- Fakultät für Chemie und Chemische Biologie, Technische Universität Dortmund, Otto-Hahn-Straße 4a, 44227 Dortmund, Germany.
| | - Wolf Hiller
- Fakultät für Chemie und Chemische Biologie, Technische Universität Dortmund, Otto-Hahn-Straße 4a, 44227 Dortmund, Germany.
| | - Markus Beck Erlach
- Fakultät für Biologie und Vorklinische Medizin, Universität Regensburg, 93040 Regensburg, Germany
| | - Werner Kremer
- Fakultät für Biologie und Vorklinische Medizin, Universität Regensburg, 93040 Regensburg, Germany
| | - Hans Robert Kalbitzer
- Fakultät für Biologie und Vorklinische Medizin, Universität Regensburg, 93040 Regensburg, Germany
| | - Dominik Marx
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany.
| | - Stefan M Kast
- Fakultät für Chemie und Chemische Biologie, Technische Universität Dortmund, Otto-Hahn-Straße 4a, 44227 Dortmund, Germany.
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7
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Holland DC, Carroll AR. Structure Revision of Formyl Phloroglucinol Meroterpenoids: A Unified Approach Using NMR Fingerprinting and DFT NMR and ECD Analyses. Molecules 2024; 29:594. [PMID: 38338339 PMCID: PMC10856187 DOI: 10.3390/molecules29030594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 02/12/2024] Open
Abstract
NMR fingerprints are valuable tools for analyzing complex natural product mixtures and identifying incorrectly assigned structures in the literature. Our diagnostic NMR fingerprints for formyl phloroglucinol meroterpenoids revealed discrepancies in the structures reported for eucalyprobusal C (1a) and eucalypcamal K (2a). NMR fingerprinting PCA analyses identified 1a as an oxepine-diformyl phloroglucinol and 2a as an oxepine 3-acyl-1-formyl phloroglucinol, contrary to their initial assignments as pyrano-diformyl and pyrano 3-acyl-1-formyl phloroglucinols, respectively. Extensive reinterpretation of their reported one- and two-dimensional NMR data, coupled with GIAO DFT-calculated 1H and 13C NMR chemical shift and DP4+ analyses, supported the unequivocal reassignment of eucalyprobusal C to 1b and eucalypcamal K to 2b. The absolute configurations of the revised oxepine-containing phloroglucinol meroterpenoids were confirmed via the reinterpretation of their reported ROESY and NOESY NMR data, along with comparative TDDFT-calculated and experimental ECD spectra.
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Affiliation(s)
- Darren C. Holland
- School of Environment and Science, Griffith University, Nathan, QLD 4111, Australia
- Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD 4111, Australia
| | - Anthony R. Carroll
- School of Environment and Science, Griffith University, Nathan, QLD 4111, Australia
- Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD 4111, Australia
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8
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Zhang KT, Huang ZP, Xu XR, Li SH, Xu YX, Zhao Q, Zhang XM. Two new diketopiperazines from the Cordyceps fungus Samsoniella sp. XY4. J Antibiot (Tokyo) 2023; 76:735-740. [PMID: 37789127 DOI: 10.1038/s41429-023-00662-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 09/18/2023] [Accepted: 09/21/2023] [Indexed: 10/05/2023]
Abstract
Two new diketopiperazines, namely samsoniellain A (1) and samsoniellain B (2), together with two known compounds (3, 4) were isolated from Cordyceps fungus Samsoniella sp. XY4. The planar structures of 1 and 2 were determined by HRESIMS, 1D and 2D NMR spectroscopy. The absolute configurations of 1 and 2 were determined by comparison of quantum chemical TDDFT calculated and experimental ECD spectra. Results of antimicrobial activity indicated that compound 2 showed weak bacteriostatic activities against S. typhimurium χ 8956, H. influenza ATCC 10211, MRSA 2024 with the MIC values of 128, 256, and 256 μg ml-1, respectively. This is the first report about secondary metabolites of Samsoniella sp.
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Affiliation(s)
- Ke-Tao Zhang
- School of Basic Medical Science, School of Chinese Medicine, Yunnan University of Chinese Medicine, Kun Ming, 650500, Yunnan, China
| | - Zhi-Pu Huang
- School of Basic Medical Science, School of Chinese Medicine, Yunnan University of Chinese Medicine, Kun Ming, 650500, Yunnan, China
| | - Xiao-Rong Xu
- School of Basic Medical Science, School of Chinese Medicine, Yunnan University of Chinese Medicine, Kun Ming, 650500, Yunnan, China
| | - Si-Heng Li
- School of Basic Medical Science, School of Chinese Medicine, Yunnan University of Chinese Medicine, Kun Ming, 650500, Yunnan, China
| | - Yu-Xiao Xu
- School of Basic Medical Science, School of Chinese Medicine, Yunnan University of Chinese Medicine, Kun Ming, 650500, Yunnan, China
| | - Qing Zhao
- School of Basic Medical Science, School of Chinese Medicine, Yunnan University of Chinese Medicine, Kun Ming, 650500, Yunnan, China.
| | - Xiao-Mei Zhang
- School of Basic Medical Science, School of Chinese Medicine, Yunnan University of Chinese Medicine, Kun Ming, 650500, Yunnan, China.
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9
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Palafox MA, Belskaya NP, Kostova IP. Study of the Molecular Architectures of 2-(4-Chlorophenyl)-5-(pyrrolidin-1-yl)-2 H-1,2,3-triazole-4-carboxylic Acid Using Their Vibrational Spectra, Quantum Chemical Calculations and Molecular Docking with MMP-2 Receptor. Pharmaceutics 2023; 15:2686. [PMID: 38140027 PMCID: PMC10747663 DOI: 10.3390/pharmaceutics15122686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/15/2023] [Accepted: 11/22/2023] [Indexed: 12/24/2023] Open
Abstract
1,2,3-triazole skeleton is a valuable building block for the discovery of new promising anticancer agents. In the present work, the molecular structure of the synthesized anticancer drug 2-(4-chlorophenyl)-5-(pyrrolidin-1-yl)-2H-1,2,3-triazole-4-carboxylic acid (1b) and its anionic form (2b) was characterized by means of the B3LYP, M06-2X and MP2 quantum chemical methods, optimizing their monomer, cyclic dimer and stacking forms using the Gaussian16 program package. The molecular structure was found to be slightly out of plane. The good agreement between the IR and Raman bands experimentally observed in the solid state with those calculated theoretically confirms the synthesized structures. All of the bands were accurately assigned according to functional calculations (DFT) in the monomer and dimer forms, together with the polynomic scaling equation procedure (PSE). Therefore, the effect of the substituents on the triazole ring and the effect of the chlorine atom on the molecular structure and on the vibrational spectra were evaluated through comparison with its non-substituted form. Through molecular docking calculations, it was evaluated as to how molecule 1b interacts with few amino acids of the MMP-2 metalloproteinase receptor, using Sybyl-X 2.0 software. Thus, the relevance of triazole scaffolds in established hydrogen bond-type interactions was demonstrated.
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Affiliation(s)
- Mauricio Alcolea Palafox
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense, 28040 Madrid, Spain
| | - Nataliya P. Belskaya
- Department of Technology for Organic Synthesis, Ural Federal University, 19 Mira Str., 620012 Yekaterinburg, Russia;
| | - Irena P. Kostova
- Department of Chemistry, Faculty of Pharmacy, Medical University of Sofia, 2 Dunav Str., 1000 Sofia, Bulgaria
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10
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Maqbool T, Younas H, Bilal M, Rasool N, Bajaber MA, Mubarik A, Parveen B, Ahmad G, Ali Shah SA. Synthesis of 1-(4-Bromobenzoyl)-1,3-dicyclohexylurea and Its Arylation via Readily Available Palladium Catalyst-Their Electronic, Spectroscopic, and Nonlinear Optical Studies via a Computational Approach. ACS OMEGA 2023; 8:30306-30314. [PMID: 37636953 PMCID: PMC10448694 DOI: 10.1021/acsomega.3c03183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 07/28/2023] [Indexed: 08/29/2023]
Abstract
In this study, we reported the synthesis of 1-(4-bromobenzoyl)-1,3-dicyclohexylurea by the reaction of DCC (N,N'-dicyclohexylcarbodiimide) with 4-bromobenzoic acid. Subsequently, we further synthesized a new series of 1-(4-arylbenzoyl)-1,3-dicyclohexylurea (5a-g) derivatives using a Suzuki cross-coupling reaction between 1-(4-bromobenzoyl)-1,3-dicyclohexylurea (3) and various aryl/heteroaryl boronic acids (4). Thus, density functional theory (DFT) calculations have been performed to examine the electronic structure of the synthesized compounds (3, 5a-g) and to calculate their spectroscopic data. Moreover, optimized geometries and thermodynamic properties, such as frontier molecular orbitals (HOMO, LUMO), molecular electrostatic potential surfaces, and reactivity descriptors, were also calculated at the PBE0-D3BJ/def2-TZVP/SMD1,4-dioxane level of theory to validate the structures of the synthesized compounds.
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Affiliation(s)
- Tahir Maqbool
- Department
of Chemistry, Government College University
Faisalabad, Faisalabad 38000, Pakistan
| | - Humera Younas
- Department
of Chemistry, Government College University
Faisalabad, Faisalabad 38000, Pakistan
| | - Muhammad Bilal
- School
of Chemistry and Chemical Engineering, Shandong
University, Jinan 250100, China
| | - Nasir Rasool
- Department
of Chemistry, Government College University
Faisalabad, Faisalabad 38000, Pakistan
| | - Majed A. Bajaber
- Department
of Chemistry, Faculty of Science, King Khalid
University, P.O. Box 9004, Abha 61413, Saudi Arabia
| | - Adeel Mubarik
- Department
of Chemistry, Government College University
Faisalabad, Faisalabad 38000, Pakistan
| | - Bushra Parveen
- Department
of Chemistry, Government College University
Faisalabad, Faisalabad 38000, Pakistan
| | - Gulraiz Ahmad
- Department
of Chemistry, Government College University
Faisalabad, Faisalabad 38000, Pakistan
| | - Syed Adnan Ali Shah
- Faculty
of Pharmacy, Universiti Teknologi MARA Cawangan
Selangor Kampus Puncak Alam, 42300 Bandar Puncak Alam, Selangor, Malaysia
- Atta-ur-Rahman
Institute for Natural Product Discovery (AuRIns), Universiti Teknologi MARA Ca-wangan Selangor Kampus Puncak Alam, 42300 Bandar Puncak
Alam, Selangor, Malaysia
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11
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Ramírez-García JC, Vázquez-Ramírez R, Patiño ME, Aguirre-Cabrera C, Carranza V, Álvarez CMG. Theoretical study of Gibbs free energy and NMR chemical shifts, of the effect of methyl substituents on the isomers of (E)-1-(α,Ꞵ-Dimethylbenzyliden)-2,2-diphenylhydrazine. AN ACAD BRAS CIENC 2023; 95:e20220766. [PMID: 37466538 DOI: 10.1590/0001-3765202320220766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Accepted: 02/27/2023] [Indexed: 07/20/2023] Open
Abstract
A theoretical analysis of free Gibbs Energy and NMR 1H 13C chemical shifts of the effect of introduce methyl groups on diphenyl rings, to produce different isomers of (E)-1-(α,Ꞵ-dimethylbenzylidene)-2,2-diphenylhydrazine, is presented. IR vibrational frequencies, Mulliken charges, molecular electrostatic potential (MEP), Gibbs free energy (G) and 1H- and 13C-NMR chemical shifts were obtained by theoretical calculations. In this analysis it was found that the position of the methyl group affects the values of the 1H- and 13C-NMR chemical shifts and the ∆G and ∆H thermodynamic properties of formation and reaction, these properties vary with the same trend, for the isomers studied. Gibbs free energy calculations show that the theoretical (E)-1-(3,4-Dimethylbenzylidene)-2,2-diphenylhydrazine isomer is the most stable, which explains the success of the experimental synthesis of this compound among the other isomers. For this molecule, the C of the HC=N group is the most nucleophilic and the H is the least acidic. The 1H-NMR chemical shifts of protons show a strong correlation with the C=N distance. It was also observed that methyl affects the ν(C=N) frequencies, the C=N distance increases when the inductive effect of the methyl groups is in the structure.
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Affiliation(s)
- Juan Carlos Ramírez-García
- Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Av. 14 Sur Col. San Manuel, Ciudad Universitaria, Puebla, C.P. 72592 México
| | - Ricardo Vázquez-Ramírez
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, D.F. 04510, México
| | - María Eugenia Patiño
- Centro de Química, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Av. 14 Sur Col. Jardines de San Manuel, Ciudad Universitaria, Puebla, P.O. Box 1067, C.P. 72001 México
| | - Carla Aguirre-Cabrera
- Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Av. 14 Sur Col. San Manuel, Ciudad Universitaria, Puebla, C.P. 72592 México
| | - Vladimir Carranza
- Centro de Química, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Av. 14 Sur Col. Jardines de San Manuel, Ciudad Universitaria, Puebla, P.O. Box 1067, C.P. 72001 México
| | - Carmen Mária González Álvarez
- Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Av. 14 Sur Col. San Manuel, Ciudad Universitaria, Puebla, C.P. 72592 México
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12
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Matveevskaya VV, Pavlov DI, Kovrizhina AR, Sukhikh TS, Sadykov EH, Dorovatovskii PV, Lazarenko VA, Khlebnikov AI, Potapov AS. Experimental and Computational Investigation of the Oxime Bond Stereochemistry in c-Jun N-terminal Kinase 3 Inhibitors 11 H-Indeno[1,2- b]quinoxalin-11-one Oxime and Tryptanthrin-6-oxime. Pharmaceutics 2023; 15:1802. [PMID: 37513989 PMCID: PMC10383563 DOI: 10.3390/pharmaceutics15071802] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 06/16/2023] [Accepted: 06/21/2023] [Indexed: 07/30/2023] Open
Abstract
11H-Indeno[1,2-b]quinoxalin-11-one oxime (IQ-1) and tryptanthrin-6-oxime are potent c-Jun N-terminal kinase 3 (JNK-3) inhibitors demonstrating neuroprotective, anti-inflammatory and anti-arthritic activity. However, the stereochemical configuration of the oxime carbon-nitrogen double bond (E- or Z-) in these compounds was so far unknown. In this contribution, we report the results of the determination of the double bond configuration in the solid state by single crystal X-ray diffraction and in solution by 1D and 2D NMR techniques and DFT calculations. It was found that both in the solid state and in solution, IQ-1 adopts the E-configuration stabilized by intermolecular hydrogen bonds, in contrast to previously assumed Z-configuration that could be stabilized only by an intramolecular hydrogen bond.
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Affiliation(s)
- Vladislava V Matveevskaya
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, 3 Lavrentiev Ave., 630090 Novosibirsk, Russia
| | - Dmitry I Pavlov
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, 3 Lavrentiev Ave., 630090 Novosibirsk, Russia
| | - Anastasia R Kovrizhina
- Kizhner Research Center, National Research Tomsk Polytechnic University, 30 Lenin Ave., 634050 Tomsk, Russia
| | - Taisiya S Sukhikh
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, 3 Lavrentiev Ave., 630090 Novosibirsk, Russia
| | - Evgeniy H Sadykov
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, 3 Lavrentiev Ave., 630090 Novosibirsk, Russia
| | - Pavel V Dorovatovskii
- National Research Centre "Kurchatov Institute", Kurchatov Square 1, 123182 Moscow, Russia
| | - Vladimir A Lazarenko
- National Research Centre "Kurchatov Institute", Kurchatov Square 1, 123182 Moscow, Russia
| | - Andrei I Khlebnikov
- Kizhner Research Center, National Research Tomsk Polytechnic University, 30 Lenin Ave., 634050 Tomsk, Russia
| | - Andrei S Potapov
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, 3 Lavrentiev Ave., 630090 Novosibirsk, Russia
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13
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Safronov NE, Kostova IP, Palafox MA, Belskaya NP. Combined NMR Spectroscopy and Quantum-Chemical Calculations in Fluorescent 1,2,3-Triazole-4-carboxylic Acids Fine Structures Analysis. Int J Mol Sci 2023; 24:8947. [PMID: 37240293 PMCID: PMC10219572 DOI: 10.3390/ijms24108947] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 05/09/2023] [Accepted: 05/14/2023] [Indexed: 05/28/2023] Open
Abstract
The peculiarities of the optical properties of 2-aryl-1,2,3-triazole acids and their sodium salts were investigated in different solvents (1,4-dioxane, dimethyl sulfoxide DMSO, methanol MeOH) and in mixtures with water. The results were discussed in terms of the molecular structure formed by inter- and intramolecular noncovalent interactions (NCIs) and their ability to ionize in anions. Theoretical calculations using the Time-Dependent Density Functional Theory (TDDFT) were carried out in different solvents to support the results. In polar and nonpolar solvents (DMSO, 1,4-dioxane), fluorescence was provided by strong neutral associates. Protic MeOH can weaken the acid molecules' association, forming other fluorescent species. The fluorescent species in water exhibited similar optical characteristics to those of triazole salts; therefore, their anionic character can be assumed. Experimental 1H and 13C-NMR spectra were compared to their corresponding calculated spectra using the Gauge-Independent Atomic Orbital (GIAO) method and several relationships were established. All these findings showed that the obtained photophysical properties of the 2-aryl-1,2,3-triazole acids noticeably depend on the environment and, therefore, are good candidates as sensors for the identification of analytes with labile protons.
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Affiliation(s)
- Nikita E. Safronov
- Department of Technology for Organic Synthesis, Ural Federal University, 19 Mira Str., Yekaterinburg 620002, Russia; (N.E.S.); (N.P.B.)
| | - Irena P. Kostova
- Department of Chemistry, Faculty of Pharmacy, Medical University—Sofia, 2 Dunav Str., 1000 Sofia, Bulgaria
| | - Mauricio Alcolea Palafox
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense, 28040 Madrid, Spain;
| | - Nataliya P. Belskaya
- Department of Technology for Organic Synthesis, Ural Federal University, 19 Mira Str., Yekaterinburg 620002, Russia; (N.E.S.); (N.P.B.)
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14
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Baxter JR, Holland DC, Gavranich B, Nicolle D, Hayton JB, Avery VM, Carroll AR. NMR Fingerprints of Formyl Phloroglucinol Meroterpenoids and Their Application to the Investigation of Eucalyptus gittinsii subsp. gittinsii. JOURNAL OF NATURAL PRODUCTS 2023; 86:1317-1334. [PMID: 37171174 DOI: 10.1021/acs.jnatprod.3c00139] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
NMR fingerprints provide powerful tools to identify natural products in complex mixtures. Principal component analysis and machine learning using 1H and 13C NMR data, alongside structural information from 180 published formyl phloroglucinols, have generated diagnostic NMR fingerprints to categorize subclasses within this group. This resulted in the reassignment of 167 NMR chemical shifts ascribed to 44 compounds. Three pyrano-diformyl phloroglucinols, euglobal In-1 and psiguadiols E and G, contained 1H and 13C NMR data inconsistent with their predicted phloroglucinol subclass. Subsequent reinterpretation of their 2D NMR data combined with DFT 13C NMR chemical shift and ECD calculations led to their structure revisions. Direct covariance processing of HMBC data permitted 1H resonances for individual compounds in mixtures to be associated, and analysis of their 1H/13C HMBC correlations using the fingerprint tool further classified components into phloroglucinol subclasses. NMR fingerprinting HMBC data obtained for six eucalypt flower extracts identified three subclasses of pyrano-acyl-formyl phloroglucinols from Eucalyptus gittinsii subsp. gittinsii. New, eucalteretial F and (+)-eucalteretial B, and known, (-)-euglobal VII and eucalrobusone C, compounds, each belonging to predicted subclasses, were isolated and characterized. Staphylococcus aureus and Plasmodium falciparum screening revealed eucalrobusone C as the most potent antiplasmodial formyl phloroglucinol to date.
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Affiliation(s)
- James R Baxter
- School of Environment and Science, Griffith University, Gold Coast, Qld 4222, Australia
| | - Darren C Holland
- School of Environment and Science, Griffith University, Gold Coast, Qld 4222, Australia
| | - Brody Gavranich
- School of Environment and Science, Griffith University, Gold Coast, Qld 4222, Australia
| | - Dean Nicolle
- Currency Creek Arboretum, PO Box 808, Melrose Park, SA 5039, Australia
| | - Joshua B Hayton
- School of Environment and Science, Griffith University, Gold Coast, Qld 4222, Australia
| | - Vicky M Avery
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, Qld 4111, Australia
- Discovery Biology, Griffith University, Brisbane, QLD 4111, Australia
| | - Anthony R Carroll
- School of Environment and Science, Griffith University, Gold Coast, Qld 4222, Australia
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, Qld 4111, Australia
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15
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Gadikota V, Govindapur RR, Reddy DS, Roseman HJ, Williamson RT, Raab JG. Anomalous 1 H NMR chemical shift behavior of substituted benzoic acid esters. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2023; 61:248-252. [PMID: 36416132 DOI: 10.1002/mrc.5326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 10/05/2022] [Accepted: 11/21/2022] [Indexed: 06/16/2023]
Abstract
Benzoic acid esters represent key building blocks for many drug discovery and development programs and have been advanced as potent PDE4 inhibitors for inhaled administration for treatment of respiratory diseases. This class of compounds has also been employed in myriad industrial processes and as common food preservatives. Recent work directed toward the synthesis of intermediates for a proprietary medicinal chemistry program led us to observe that the 1 H NMR chemical shifts of substituents ortho to the benzoic acid ester moiety defied conventional iterative chemical shift prediction protocols. To explore these unexpected results, we initiated a detailed computational study employing density functional theory (DFT) calculations to better understand the unexpectedly large variance in expected versus experimental NMR chemical shifts.
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Affiliation(s)
- Vidya Gadikota
- A1 BioChem Labs LLC, Wilmington, North Carolina, 28409, USA
| | | | | | | | - R Thomas Williamson
- Department of Chemistry and Biochemistry, University of North Carolina Wilmington, Wilmington, North Carolina, 28409, USA
| | - Jeffrey G Raab
- Department of Chemistry and Biochemistry, University of North Carolina Wilmington, Wilmington, North Carolina, 28409, USA
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16
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Hou B, Li K, He H, Hu J, Xu Z, Xiang Q, Wang P, Chen X, Sun Z. Stable Crystalline Nanohoop Radical and Its Self-Association Promoted by van der Waals Interactions. Angew Chem Int Ed Engl 2023; 62:e202301046. [PMID: 36754831 DOI: 10.1002/anie.202301046] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/07/2023] [Accepted: 02/08/2023] [Indexed: 02/10/2023]
Abstract
A stable nanohoop radical (OR3) combining the structures of cycloparaphenylene and an olympicenyl radical is synthesized and isolated in the crystalline state. X-ray crystallographic analysis reveals that OR3 forms a unique head-to-tail dimer that further aggregates into a one-dimensional chain in the solid state. Variable-temperature NMR and concentration-dependent absorption measurements indicate that the π-dimer is not formed in solution. An energy decomposition analysis indicates that van der Waals interactions are the driving force for the self-association process, in contrast with other olympicenyl derivatives that favor π-dimerization. The physical properties in solution phase have been studied, and the stable cationic species obtained by one-electron chemical oxidation. This study offers a new molecular design to modulate the self-association of organic radicals for overcoming the spin-Peierls transition, and to prepare novel nanohoop compounds with spin-related properties.
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Affiliation(s)
- Bingxia Hou
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Ke Li
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Huijie He
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Jinlian Hu
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Zhuofan Xu
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Qin Xiang
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Peng Wang
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Xing Chen
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
| | - Zhe Sun
- Institute of Molecular Plus, Department of Chemistry and Haihe Laboratory of Sustainable Chemical Transformations, Tianjin university, 92 Weijin Road, Tianjin, 300072, China
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17
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Kovács T, Lajter I, Kúsz N, Schelz Z, Bózsity-Faragó N, Borbás A, Zupkó I, Krupitza G, Frisch R, Hohmann J, Vasas A, Mándi A. Isolation and NMR Scaling Factors for the Structure Determination of Lobatolide H, a Flexible Sesquiterpene from Neurolaena lobata. Int J Mol Sci 2023; 24:ijms24065841. [PMID: 36982924 PMCID: PMC10052924 DOI: 10.3390/ijms24065841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 03/11/2023] [Accepted: 03/13/2023] [Indexed: 03/30/2023] Open
Abstract
A new flexible germacranolide (1, lobatolide H) was isolated from the aerial parts of Neurolaena lobata. The structure elucidation was performed by classical NMR experiments and DFT NMR calculations. Altogether, 80 theoretical level combinations with existing 13C NMR scaling factors were tested, and the best performing ones were applied on 1. 1H and 13C NMR scaling factors were also developed for two combinations utilizing known exomethylene containing derivatives, and the results were complemented by homonuclear coupling constant (JHH) and TDDFT-ECD calculations to elucidate the stereochemistry of 1. Lobatolide H possessed remarkable antiproliferative activity against human cervical tumor cell lines with different HPV status (SiHa and C33A), induced cell cycle disturbance and exhibited a substantial antimigratory effect in SiHa cells.
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Affiliation(s)
- Tibor Kovács
- Department of Organic Chemistry, University of Debrecen, P.O. Box 400, 4002 Debrecen, Hungary
- Doctoral School of Chemistry, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - Ildikó Lajter
- Institute of Pharmacognosy, University of Szeged, Eötvös u. 6, 6720 Szeged, Hungary
| | - Norbert Kúsz
- Institute of Pharmacognosy, University of Szeged, Eötvös u. 6, 6720 Szeged, Hungary
| | - Zsuzsanna Schelz
- Institute of Pharmacodynamics and Biopharmacy, University of Szeged, Eötvös u. 6, 6720 Szeged, Hungary
| | - Noémi Bózsity-Faragó
- Institute of Pharmacodynamics and Biopharmacy, University of Szeged, Eötvös u. 6, 6720 Szeged, Hungary
| | - Anikó Borbás
- Department of Pharmaceutical Chemistry, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - István Zupkó
- Institute of Pharmacodynamics and Biopharmacy, University of Szeged, Eötvös u. 6, 6720 Szeged, Hungary
| | - Georg Krupitza
- Department of Pathology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Richard Frisch
- Institute for Ethnobiology, Playa Diana, San José GT-170, Guatemala
| | - Judit Hohmann
- Institute of Pharmacognosy, University of Szeged, Eötvös u. 6, 6720 Szeged, Hungary
- ELKH-USZ Biologically Active Natural Products Research Group, University of Szeged, Eötvös u. 6, 6720 Szeged, Hungary
| | - Andrea Vasas
- Institute of Pharmacognosy, University of Szeged, Eötvös u. 6, 6720 Szeged, Hungary
- ELKH-USZ Biologically Active Natural Products Research Group, University of Szeged, Eötvös u. 6, 6720 Szeged, Hungary
| | - Attila Mándi
- Department of Organic Chemistry, University of Debrecen, P.O. Box 400, 4002 Debrecen, Hungary
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18
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Cohen RD, Wood JS, Lam YH, Buevich AV, Sherer EC, Reibarkh M, Williamson RT, Martin GE. DELTA50: A Highly Accurate Database of Experimental 1H and 13C NMR Chemical Shifts Applied to DFT Benchmarking. Molecules 2023; 28:molecules28062449. [PMID: 36985422 PMCID: PMC10051451 DOI: 10.3390/molecules28062449] [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: 01/25/2023] [Revised: 02/23/2023] [Accepted: 02/28/2023] [Indexed: 03/30/2023] Open
Abstract
Density functional theory (DFT) benchmark studies of 1H and 13C NMR chemical shifts often yield differing conclusions, likely due to non-optimal test molecules and non-standardized data acquisition. To address this issue, we carefully selected and measured 1H and 13C NMR chemical shifts for 50 structurally diverse small organic molecules containing atoms from only the first two rows of the periodic table. Our NMR dataset, DELTA50, was used to calculate linear scaling factors and to evaluate the accuracy of 73 density functionals, 40 basis sets, 3 solvent models, and 3 gauge-referencing schemes. The best performing DFT methodologies for 1H and 13C NMR chemical shift predictions were WP04/6-311++G(2d,p) and ωB97X-D/def2-SVP, respectively, when combined with the polarizable continuum solvent model (PCM) and gauge-independent atomic orbital (GIAO) method. Geometries should be optimized at the B3LYP-D3/6-311G(d,p) level including the PCM solvent model for the best accuracy. Predictions of 20 organic compounds and natural products from a separate probe set had root-mean-square deviations (RMSD) of 0.07 to 0.19 for 1H and 0.5 to 2.9 for 13C. Maximum deviations were less than 0.5 and 6.5 ppm for 1H and 13C, respectively.
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Affiliation(s)
- Ryan D Cohen
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
- Department of Chemistry and Biochemistry, Seton Hall University, South Orange, NJ 07079, USA
| | - Jared S Wood
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
- Department of Chemistry and Biochemistry, University of North Carolina Wilmington, Wilmington, NC 28409, USA
| | - Yu-Hong Lam
- Department of Computational and Structural Chemistry, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Alexei V Buevich
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Edward C Sherer
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Mikhail Reibarkh
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - R Thomas Williamson
- Department of Chemistry and Biochemistry, University of North Carolina Wilmington, Wilmington, NC 28409, USA
| | - Gary E Martin
- Department of Chemistry and Biochemistry, Seton Hall University, South Orange, NJ 07079, USA
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19
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Collins S, Linnolahti M. Ionization of Cp 2 ZrMe 2 and Lewis Bases by Methylaluminoxane: Computational Insights. Chemphyschem 2023; 24:e202200759. [PMID: 36321588 DOI: 10.1002/cphc.202200759] [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: 10/12/2022] [Revised: 10/20/2022] [Indexed: 11/06/2022]
Abstract
The interactions of the Lewis bases CO, octamethyltrisiloxane (OMTS) and 2,2'-bipyridine (bipy) with a sheet model for the principal activator (MeAlO)16 (Me3 Al)6 (16,6) in hydrolytic methylaluminoxane (MAO) were investigated by DFT. These studies reveal that OMTS and bipy form adducts with Me3 Al prior to methide abstraction by 16,6 to form the ion-pairs [Me2 Al(κ2 -L)][16,6] (5: L=OMTS, 6: L=bipy, [16,6]- =[(MeAlO)16 (Me3 Al)6 Me]- ) while CO simply binds to a reactive edge site without ionization. The binding and activation of Cp2 ZrMe2 with 16,6 to form both neutral adducts 1 Cp2 ZrMe2 ⋅16,6 and contact ion-pairs 4 and 7, both with formula [Cp2 ZrMe][μ-Me(MeAlO)16 (Me3 Al)6 ], featuring terminal and chelated MAO-anions, respectively was studied by DFT. The displacement of the anion with either excess Cp2 ZrMe2 or Me3 Al was also studied, forming outer-sphere ion-pairs [(Cp2 ZrMe)2 μ-Me][16,6] (2) and [Cp2 Zr(μ-Me)2 AlMe2 ][16,6] (3). The theoretical NMR spectra of these species were compared to experimental spectra of MAO and Cp2 ZrMe2 and found to be in good agreement with the reported data and assignments. These studies confirm that 16,6 is a very suitable model for the activators present in MAO but highlight the difficulty in accurately calculating thermodynamic quantities for molecules in this size regime.
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Affiliation(s)
- Scott Collins
- Department of Chemistry, University of Eastern Finland, Joensuu Campus, Yliopistokatu 7, F80100, Joensuu, Finland.,Former address: Department of Chemistry, University of Victoria, 3800 Finnerty Rd., Victoria, BC, Canada
| | - Mikko Linnolahti
- Department of Chemistry, University of Eastern Finland, Joensuu Campus, Yliopistokatu 7, F80100, Joensuu, Finland
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20
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Rivera NR, Cohen RD, Zhang SW, Dance ZEX, Halsey HM, Song S, Bu X, Reibarkh M, Ren H, Lee AY, Chang D, Lohani S. Gefapixant Citrate (MK-7264) Sulfonamide Step Speciation Study: Investigation into Precipitation–Dissolution Events during Addition of Chlorosulfonic Acid. Org Process Res Dev 2023. [DOI: 10.1021/acs.oprd.2c00313] [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]
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21
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Bioactivity and Metabolome Mining of Deep-Sea Sediment-Derived Microorganisms Reveal New Hybrid PKS-NRPS Macrolactone from Aspergillus versicolor PS108-62. Mar Drugs 2023; 21:md21020095. [PMID: 36827136 PMCID: PMC9961484 DOI: 10.3390/md21020095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 01/24/2023] [Accepted: 01/25/2023] [Indexed: 01/31/2023] Open
Abstract
Despite low temperatures, poor nutrient levels and high pressure, microorganisms thrive in deep-sea environments of polar regions. The adaptability to such extreme environments renders deep-sea microorganisms an encouraging source of novel, bioactive secondary metabolites. In this study, we isolated 77 microorganisms collected by a remotely operated vehicle from the seafloor in the Fram Strait, Arctic Ocean (depth of 2454 m). Thirty-two bacteria and six fungal strains that represented the phylogenetic diversity of the isolates were cultured using an One-Strain-Many-Compounds (OSMAC) approach. The crude EtOAc extracts were tested for antimicrobial and anticancer activities. While antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and Enterococcus faecium was common for many isolates, only two bacteria displayed anticancer activity, and two fungi inhibited the pathogenic yeast Candida albicans. Due to bioactivity against C. albicans and rich chemical diversity based on molecular network-based untargeted metabolomics, Aspergillus versicolor PS108-62 was selected for an in-depth chemical investigation. A chemical work-up of the SPE-fractions of its dichloromethane subextract led to the isolation of a new PKS-NRPS hybrid macrolactone, versicolide A (1), a new quinazoline (-)-isoversicomide A (3), as well as three known compounds, burnettramic acid A (2), cyclopenol (4) and cyclopenin (5). Their structures were elucidated by a combination of HRMS, NMR, [α]D, FT-IR spectroscopy and computational approaches. Due to the low amounts obtained, only compounds 2 and 4 could be tested for bioactivity, with 2 inhibiting the growth of C. albicans (IC50 7.2 µg/mL). These findings highlight, on the one hand, the vast potential of the genus Aspergillus to produce novel chemistry, particularly from underexplored ecological niches such as the Arctic deep sea, and on the other, the importance of untargeted metabolomics for selection of marine extracts for downstream chemical investigations.
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22
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Precisely predicting the 1H and 13C NMR chemical shifts in new types of nerve agents and building spectra database. Sci Rep 2022; 12:20288. [PMID: 36434133 PMCID: PMC9700684 DOI: 10.1038/s41598-022-24647-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Accepted: 11/17/2022] [Indexed: 11/27/2022] Open
Abstract
Following the recent terrorist attacks using Novichok agents and the subsequent decomposition operations, understanding the chemical structures of nerve agents has become important. To mitigate the ever-evolving threat of new variants, the Organization for the Prohibition of Chemical Weapons has updated the list of Schedule 1 substances defined by the Chemical Weapons Convention. However, owing to the several possible structures for each listed substance, obtaining an exhaustive dataset is almost impossible. Therefore, we propose a nuclear magnetic resonance-based prediction method for 1H and 13C NMR chemical shifts of Novichok agents based on conformational and density functional study calculations. Four organophosphorus compounds and five G- and V-type nerve agents were used to evaluate the accuracy of the proposed procedure. Moreover, 1H and 13C NMR prediction results for an additional 83 Novichok candidates were compiled as a database to aid future research and identification. Further, this is the first study to successfully predict the NMR chemical shifts of Novichok agents, with an exceptional agreement between predicted and experimental data. The conclusions enable the prediction of all possible structures of Novichok agents and can serve as a firm foundation for preparation against future terrorist attacks using new variants of nerve agents.
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23
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Yesiltepe Y, Govind N, Metz TO, Renslow RS. An initial investigation of accuracy required for the identification of small molecules in complex samples using quantum chemical calculated NMR chemical shifts. J Cheminform 2022; 14:64. [PMID: 36138446 PMCID: PMC9499888 DOI: 10.1186/s13321-022-00587-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 02/06/2022] [Indexed: 11/24/2022] Open
Abstract
The majority of primary and secondary metabolites in nature have yet to be identified, representing a major challenge for metabolomics studies that currently require reference libraries from analyses of authentic compounds. Using currently available analytical methods, complete chemical characterization of metabolomes is infeasible for both technical and economic reasons. For example, unambiguous identification of metabolites is limited by the availability of authentic chemical standards, which, for the majority of molecules, do not exist. Computationally predicted or calculated data are a viable solution to expand the currently limited metabolite reference libraries, if such methods are shown to be sufficiently accurate. For example, determining nuclear magnetic resonance (NMR) spectroscopy spectra in silico has shown promise in the identification and delineation of metabolite structures. Many researchers have been taking advantage of density functional theory (DFT), a computationally inexpensive yet reputable method for the prediction of carbon and proton NMR spectra of metabolites. However, such methods are expected to have some error in predicted 13C and 1H NMR spectra with respect to experimentally measured values. This leads us to the question-what accuracy is required in predicted 13C and 1H NMR chemical shifts for confident metabolite identification? Using the set of 11,716 small molecules found in the Human Metabolome Database (HMDB), we simulated both experimental and theoretical NMR chemical shift databases. We investigated the level of accuracy required for identification of metabolites in simulated pure and impure samples by matching predicted chemical shifts to experimental data. We found 90% or more of molecules in simulated pure samples can be successfully identified when errors of 1H and 13C chemical shifts in water are below 0.6 and 7.1 ppm, respectively, and below 0.5 and 4.6 ppm in chloroform solvation, respectively. In simulated complex mixtures, as the complexity of the mixture increased, greater accuracy of the calculated chemical shifts was required, as expected. However, if the number of molecules in the mixture is known, e.g., when NMR is combined with MS and sample complexity is low, the likelihood of confident molecular identification increased by 90%.
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Affiliation(s)
- Yasemin Yesiltepe
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, USA
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Niranjan Govind
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Thomas O Metz
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, USA
| | - Ryan S Renslow
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, USA.
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA.
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24
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Nitu S, Milea MS, Boran S, Mosoarca G, Zamfir AD, Popa S, Funar-Timofei S. Experimental and Computational Study of Novel Pyrazole Azo Dyes as Colored Materials for Light Color Paints. MATERIALS (BASEL, SWITZERLAND) 2022; 15:5507. [PMID: 36013644 PMCID: PMC9410184 DOI: 10.3390/ma15165507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/21/2022] [Accepted: 07/25/2022] [Indexed: 06/15/2023]
Abstract
This paper presents the synthesis of eight new pyrazole azo dyes using ethyl 5-amino-3-methyl-1H-pyrazole-4-carboxylate as the diazotization component and various active methylene derivatives as coupling components. These new azo dyes were characterized by spectroscopic (FT-IR, UV-VIS), and spectrometric (1H NMR, 13C NMR, MS) analyses. The dye structures were modeled by the MMFF94s force field and quantum chemical density functional theory (DFT) calculations using the B3LYP functional and the 6-311G(d,p) basis set, in the gas phase. Weak electrostatic hydrogen bonds for the azo and hydrazo dye tautomers were found in the ground state. The CIS, TD (using the B3LYP and M06-2X functionals), and ZINDO methods were used to estimate the dye UV-VIS spectra in ethanol, which were compared with the experimental ones. The anti-configuration arrangement of the π-bonds and the presence of the prevalent hydrazo dye tautomer were supported by the computed 1H NMR and 13C NMR spectra. A good accordance between the experimental and predicted absorption maxima and chemical shifts was observed. Color investigations using the CIEL*a*b* space were conducted for all dyes in powder and for their mixtures in water-based acrylic resins. The results confirm the newly synthesized dyes' color properties and that they might be used for light color paints in the varnishes industry.
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Affiliation(s)
- Sabina Nitu
- Faculty of Industrial Chemistry and Environmental Engineering, Politehnica University of Timisoara, Bd. V. Parvan, No. 6, 300223 Timisoara, Romania
| | - Marius Silviu Milea
- Faculty of Industrial Chemistry and Environmental Engineering, Politehnica University of Timisoara, Bd. V. Parvan, No. 6, 300223 Timisoara, Romania
| | - Sorina Boran
- Faculty of Industrial Chemistry and Environmental Engineering, Politehnica University of Timisoara, Bd. V. Parvan, No. 6, 300223 Timisoara, Romania
| | - Giannin Mosoarca
- Faculty of Industrial Chemistry and Environmental Engineering, Politehnica University of Timisoara, Bd. V. Parvan, No. 6, 300223 Timisoara, Romania
| | - Alina D. Zamfir
- National Institute for Research and Development in Electrochemistry and Condensed Matter, 300224 Timisoara, Romania
| | - Simona Popa
- Faculty of Industrial Chemistry and Environmental Engineering, Politehnica University of Timisoara, Bd. V. Parvan, No. 6, 300223 Timisoara, Romania
| | - Simona Funar-Timofei
- “Coriolan Dragulescu” Institute of Chemistry, Romanian Academy, 300223 Timisoara, Romania
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25
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Theoretical study of keto-enol tautomerism in 7-epi-clusianone by quantum chemical calculations of NMR chemical shifts. J Mol Model 2022; 28:239. [PMID: 35908141 DOI: 10.1007/s00894-022-05234-4] [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: 03/07/2022] [Accepted: 07/14/2022] [Indexed: 10/16/2022]
Abstract
Plants from the Garcinia genus have been used worldwide due to their therapeutic properties. Among the various metabolites isolated from this genus, 7-epi-clusianone, a tetraprenylated benzophenone, stands out for its wide range of identified biological activities. This benzophenone can exist in five tautomeric forms, although the benzene-d6 and chloroform-d3 solution nuclear magnetic resonance (NMR) spectra revealed only two tautomeric forms (B and C) in equilibrium, with concentration ratio depending on the solvent in which the spectrum was obtained. Calculated energy values suggested that tautomeric forms B and E would be prevalent in benzene-d6 solution, in contrast to the experimental data. Considering this conflicting result, we employed the statistical DP4 + method based on 13C and 1H NMR chemical shift calculations, in the gas phase and in benzene-d6 solution, to confirm that the B and C tautomeric forms of 7-epi-clusianone are the most prevalent in the experimental conditions.
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26
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Tembeni B, Sciorillo A, Invernizzi L, Klimkait T, Urda L, Moyo P, Naidoo-Maharaj D, Levitties N, Gyampoh K, Zu G, Yuan Z, Mounzer K, Nkabinde S, Nkabinde M, Gqaleni N, Tietjen I, Montaner LJ, Maharaj V. HPLC-Based Purification and Isolation of Potent Anti-HIV and Latency Reversing Daphnane Diterpenes from the Medicinal Plant Gnidia sericocephala ( Thymelaeaceae). Viruses 2022; 14:1437. [PMID: 35891417 PMCID: PMC9318819 DOI: 10.3390/v14071437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 06/21/2022] [Accepted: 06/24/2022] [Indexed: 11/17/2022] Open
Abstract
Despite the success of combination antiretroviral therapy (cART), HIV persists in low- and middle-income countries (LMIC) due to emerging drug resistance and insufficient drug accessibility. Furthermore, cART does not target latently-infected CD4+ T cells, which represent a major barrier to HIV eradication. The “shock and kill” therapeutic approach aims to reactivate provirus expression in latently-infected cells in the presence of cART and target virus-expressing cells for elimination. An attractive therapeutic prototype in LMICs would therefore be capable of simultaneously inhibiting viral replication and inducing latency reversal. Here we report that Gnidia sericocephala, which is used by traditional health practitioners in South Africa for HIV/AIDS management to supplement cART, contains at least four daphnane-type compounds (yuanhuacine A (1), yuanhuacine as part of a mixture (2), yuanhuajine (3), and gniditrin (4)) that inhibit viral replication and/or reverse HIV latency. For example, 1 and 2 inhibit HIV replication in peripheral blood mononuclear cells (PBMC) by >80% at 0.08 µg/mL, while 1 further inhibits a subtype C virus in PBMC with a half-maximal effective concentration (EC50) of 0.03 µM without cytotoxicity. Both 1 and 2 also reverse HIV latency in vitro consistent with protein kinase C activation but at 16.7-fold lower concentrations than the control prostratin. Both 1 and 2 also reverse latency in primary CD4+ T cells from cART-suppressed donors with HIV similar to prostratin but at 6.7-fold lower concentrations. These results highlight G. sericocephala and components 1 and 2 as anti-HIV agents for improving cART efficacy and supporting HIV cure efforts in resource-limited regions.
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Affiliation(s)
- Babalwa Tembeni
- Department of Chemistry, University of Pretoria, Pretoria 0028, South Africa; (B.T.); (L.I.); (P.M.); (D.N.-M.)
| | - Amanda Sciorillo
- The Wistar Institute, Philadelphia, PA 19104, USA; (A.S.); (N.L.); (K.G.); (G.Z.); (Z.Y.); (I.T.)
| | - Luke Invernizzi
- Department of Chemistry, University of Pretoria, Pretoria 0028, South Africa; (B.T.); (L.I.); (P.M.); (D.N.-M.)
| | - Thomas Klimkait
- Molecular Virology, Department of Biomedicine, University of Basel, 4031 Basel, Switzerland; (T.K.); (L.U.)
| | - Lorena Urda
- Molecular Virology, Department of Biomedicine, University of Basel, 4031 Basel, Switzerland; (T.K.); (L.U.)
| | - Phanankosi Moyo
- Department of Chemistry, University of Pretoria, Pretoria 0028, South Africa; (B.T.); (L.I.); (P.M.); (D.N.-M.)
| | - Dashnie Naidoo-Maharaj
- Department of Chemistry, University of Pretoria, Pretoria 0028, South Africa; (B.T.); (L.I.); (P.M.); (D.N.-M.)
- Agricultural Research Council-Vegetables, Industrial and Medicinal Plants, Private Bag X293, Pretoria 0001, South Africa
| | - Nathan Levitties
- The Wistar Institute, Philadelphia, PA 19104, USA; (A.S.); (N.L.); (K.G.); (G.Z.); (Z.Y.); (I.T.)
| | - Kwasi Gyampoh
- The Wistar Institute, Philadelphia, PA 19104, USA; (A.S.); (N.L.); (K.G.); (G.Z.); (Z.Y.); (I.T.)
| | - Guorui Zu
- The Wistar Institute, Philadelphia, PA 19104, USA; (A.S.); (N.L.); (K.G.); (G.Z.); (Z.Y.); (I.T.)
| | - Zhe Yuan
- The Wistar Institute, Philadelphia, PA 19104, USA; (A.S.); (N.L.); (K.G.); (G.Z.); (Z.Y.); (I.T.)
| | - Karam Mounzer
- Jonathan Lax Immune Disorders Treatment Center, Philadelphia Fight Community Health Centers, Philadelphia, PA 19107, USA;
| | | | - Magugu Nkabinde
- Ungangezulu Indigenous Remedies, J Uitval, Wasbank 2920, South Africa; (S.N.); (M.N.)
| | - Nceba Gqaleni
- Africa Health Research Institute, Congella 4013, South Africa;
- Discipline of Traditional Medicine, University of KwaZulu-Natal, Durban 4001, South Africa
- Faculty of Health Sciences, Durban University of Technology, Durban 4001, South Africa
| | - Ian Tietjen
- The Wistar Institute, Philadelphia, PA 19104, USA; (A.S.); (N.L.); (K.G.); (G.Z.); (Z.Y.); (I.T.)
| | - Luis J. Montaner
- The Wistar Institute, Philadelphia, PA 19104, USA; (A.S.); (N.L.); (K.G.); (G.Z.); (Z.Y.); (I.T.)
| | - Vinesh Maharaj
- Department of Chemistry, University of Pretoria, Pretoria 0028, South Africa; (B.T.); (L.I.); (P.M.); (D.N.-M.)
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27
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Palivec V, Pohl R, Kaminský J, Martinez-Seara H. Efficiently Computing NMR 1H and 13C Chemical Shifts of Saccharides in Aqueous Environment. J Chem Theory Comput 2022; 18:4373-4386. [PMID: 35687789 DOI: 10.1021/acs.jctc.2c00127] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Determining the structure of saccharides in their native environment is crucial to understanding their function and more accurately targeting their utilization. Nuclear magnetic resonance observables such as the nuclear Overhauser effect or spin-spin coupling constants are routinely utilized to study saccharides in their native water environment. However, while highly sensitive to the local environment, chemical shifts are mostly overlooked, despite being commonly measured for compounds identification. Although chemical shifts carry considerable structural information, their direct association with structure is notoriously difficult. This is mostly due to the similarity in the chemical nature of most saccharides causing similar physicochemical environments close to sugar C and H atoms, resulting in comparable chemical shifts. The rise of computational power allows one to compute reliable chemical shifts and use them to determine atomistic details of these sugars in solution. However, any prediction is severely limited by the computational protocol used and its accuracy. In this work, we studied a set of 31 saccharides on which we evaluated various computational protocols to calculate the total number of 375 1H and 327 13C chemical shifts of sugars in an aqueous environment. Our study proposes two cost-effective protocols for simulating 1H and 13C chemical shifts that we recommend for further use. These protocols can help with the interpretation of experimental spectra, but we also show that they are also capable of structure prediction independently. This is possible because of the low mean absolute deviations of calculated shifts from the experiment (0.06 ppm for 1H and 1.09 ppm for 13C). We explore different solvation methods, basis sets, and optimization schemes to reach such accuracy. A correct sampling of the conformation phase space of flexible sugar molecules is also key to obtaining accurately converged theoretical chemical shifts. The linear regression method was applied to convert the calculated isotropic nuclear magnetic shielding constants to simulated chemical shifts comparable with the experiment. The achieved level of accuracy can help in utilizing chemical shifts for elucidating the 3D atomistic structure of saccharides in aqueous solutions. All linear regression parameters obtained on our extensive set of sugars for all the tested protocols can be reutilized in future works.
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Affiliation(s)
- Vladimír Palivec
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo námĕstí 542/2, Prague 6 CZ166 10, Czech Republic
| | - Radek Pohl
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo námĕstí 542/2, Prague 6 CZ166 10, Czech Republic
| | - Jakub Kaminský
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo námĕstí 542/2, Prague 6 CZ166 10, Czech Republic
| | - Hector Martinez-Seara
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo námĕstí 542/2, Prague 6 CZ166 10, Czech Republic
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28
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Two new dimeric benzofuran diastereomers from the roots of Eupatorium heterophyllum. Tetrahedron Lett 2022. [DOI: 10.1016/j.tetlet.2022.153924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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29
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Pokratath R, Van den Eynden D, Cooper SR, Mathiesen JK, Waser V, Devereux M, Billinge SJL, Meuwly M, Jensen KMØ, De Roo J. Mechanistic Insight into the Precursor Chemistry of ZrO 2 and HfO 2 Nanocrystals; towards Size-Tunable Syntheses. JACS AU 2022; 2:827-838. [PMID: 35557760 PMCID: PMC9088301 DOI: 10.1021/jacsau.1c00568] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 02/24/2022] [Accepted: 02/24/2022] [Indexed: 05/09/2023]
Abstract
One can nowadays readily generate monodisperse colloidal nanocrystals, but a retrosynthetic analysis is still not possible since the underlying chemistry is often poorly understood. Here, we provide insight into the reaction mechanism of colloidal zirconia and hafnia nanocrystals synthesized from metal chloride and metal isopropoxide. We identify the active precursor species in the reaction mixture through a combination of nuclear magnetic resonance spectroscopy (NMR), density functional theory (DFT) calculations, and pair distribution function (PDF) analysis. We gain insight into the interaction of the surfactant, tri-n-octylphosphine oxide (TOPO), and the different precursors. Interestingly, we identify a peculiar X-type ligand redistribution mechanism that can be steered by the relative amount of Lewis base (L-type). We further monitor how the reaction mixture decomposes using solution NMR and gas chromatography, and we find that ZrCl4 is formed as a by-product of the reaction, limiting the reaction yield. The reaction proceeds via two competing mechanisms: E1 elimination (dominating) and SN1 substitution (minor). Using this new mechanistic insight, we adapted the synthesis to optimize the yield and gain control over nanocrystal size. These insights will allow the rational design and synthesis of complex oxide nanocrystals.
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Affiliation(s)
- Rohan Pokratath
- Department
of Chemistry, University of Basel, Mattenstrasse 24, BPR 1096, Basel 4058, Switzerland
| | - Dietger Van den Eynden
- Department
of Chemistry, University of Basel, Mattenstrasse 24, BPR 1096, Basel 4058, Switzerland
| | - Susan Rudd Cooper
- Department
of Chemistry, University of Copenhagen, Universitetsparken 5, Copenhagen 2100, Denmark
| | - Jette Katja Mathiesen
- Department
of Chemistry, University of Copenhagen, Universitetsparken 5, Copenhagen 2100, Denmark
| | - Valérie Waser
- Department
of Chemistry, University of Basel, Mattenstrasse 24, BPR 1096, Basel 4058, Switzerland
| | - Mike Devereux
- Department
of Chemistry, University of Basel, Klingelbergstrasse 80, Basel 4056, Switzerland
| | - Simon J. L. Billinge
- Applied
Physics and Applied Mathematics Department, Columbia University, New York, New York 10027, United States
- Condensed
Matter Physics and Material Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Markus Meuwly
- Department
of Chemistry, University of Basel, Klingelbergstrasse 80, Basel 4056, Switzerland
| | - Kirsten M. Ø. Jensen
- Department
of Chemistry, University of Copenhagen, Universitetsparken 5, Copenhagen 2100, Denmark
| | - Jonathan De Roo
- Department
of Chemistry, University of Basel, Mattenstrasse 24, BPR 1096, Basel 4058, Switzerland
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30
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DFT Calculations of 31P NMR Chemical Shifts in Palladium Complexes. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27092668. [PMID: 35566018 PMCID: PMC9105066 DOI: 10.3390/molecules27092668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/04/2022] [Accepted: 04/19/2022] [Indexed: 11/17/2022]
Abstract
In this study, comparative analysis of calculated (GIAO method, DFT level) and experimental 31P NMR shifts for a wide range of model palladium complexes showed that, on the whole, the theory reproduces the experimental data well. The exceptions are the complexes with the P=O phosphorus, for which there is a systematic underestimation of shielding, the value of which depends on the flexibility of the basis sets, especially at the geometry optimization stage. The use of triple-ζ quality basis sets and additional polarization functions at this stage reduces the underestimation of shielding for such phosphorus atoms. To summarize, in practice, for the rapid assessment of 31P NMR shifts, with the exception of the P=O type, a simple PBE0/{6-311G(2d,2p); Pd(SDD)}//PBE0/{6-31+G(d); Pd(SDD)} approximation is quite acceptable (RMSE = 8.9 ppm). Optimal, from the point of view of “price–quality” ratio, is the PBE0/{6-311G(2d,2p); Pd(SDD)}//PBE0/{6-311+G(2d); Pd(SDD)} (RMSE = 8.0 ppm) and the PBE0/{def2-TZVP; Pd(SDD)}//PBE0/{6-311+G(2d); Pd(SDD)} (RMSE = 6.9 ppm) approaches. In all cases, a linear scaling procedure is necessary to minimize systematic errors.
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31
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Ondrisek P, Elie M, Pupier M, de Aguirre A, Poblador‐Bahamonde AI, Besnard C, Lacour J. Acetylene Derivatives of Cationic Diazaoxatriangulenes and Diaza [4]Helicenes ‐ Access to Red Emitters and Planar Chiral Stereochemical Traits. Chemistry 2022; 28:e202104405. [PMID: 35040214 PMCID: PMC9305763 DOI: 10.1002/chem.202104405] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Indexed: 11/25/2022]
Abstract
Cationic triangulenes, and related helicenes, constitute a rich class of dyes and fluorophores, usually absorbing and emitting light at low energy, in the orange to red domains. Recently, to broaden the scope of applications, regioselective late‐stage functionalizations on these core moieties have been developed. For instance, with the introduction of electron‐donating groups (EDGs), important bathochromic shifts are observed pushing absorptions towards or in the near‐infrared (NIR) spectral domain while emissive properties disappear essentially completely. Herein, to upset this drawback, acetylene derivatives of cationic diazaoxa triangulenes (DAOTA) and [4]helicenes are prepared (16 examples). Contrary to other EDG‐functionalized derivatives, C≡C− functionalized products remain broadly fluorescent, with red‐shifted absorptions (Δλabs up to 25 nm) and emissions (Δλem up to 73 nm, ΦPL up to 51 %). Quite interestingly, a general dynamic stereoisomerism phenomenon is evidenced for the compounds derived from achiral DAOTA cores. At low temperature in 1H NMR spectroscopy (218 K), N−CH2 protons become diastereotopic with chemical shifts differences (Δδ) as high as +1.64 ppm. The signal coalescence occurs around 273 K with a barrier of ∼12 kcal mol−1. This phenomenon is due to planar chiral conformations (Sp and Rp configurations), induced by the geometry of the alkyl (n‐propyl) side‐chains next to the acetylenic substituents. Ion pairing studies with Δ‐TRISPHAT anion not only confirm the occurrence of the chiral conformations but evidence a moderate but definite asymmetric induction from the chiral anion onto the cations. Finally, DFT calculations offer a valuable insight on the geometries, the corresponding stereodynamics and also on the very large difference in NMR for some of the diastereotopic protons.
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Affiliation(s)
- Pavol Ondrisek
- Department of Organic Chemistry University of Geneva Quai Ernest Ansermet 30 1211 Geneva 4 Switzerland
| | - Margaux Elie
- Department of Organic Chemistry University of Geneva Quai Ernest Ansermet 30 1211 Geneva 4 Switzerland
| | - Marion Pupier
- Department of Organic Chemistry University of Geneva Quai Ernest Ansermet 30 1211 Geneva 4 Switzerland
| | - Adiran de Aguirre
- Department of Organic Chemistry University of Geneva Quai Ernest Ansermet 30 1211 Geneva 4 Switzerland
| | | | - Céline Besnard
- Laboratoire de Cristallographie University of Geneva Quai Ernest Ansermet 24 1211 Geneva 4 Switzerland
| | - Jérôme Lacour
- Department of Organic Chemistry University of Geneva Quai Ernest Ansermet 30 1211 Geneva 4 Switzerland
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32
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Munsimbwe L, Suganuma K, Ishikawa Y, Choongo K, Kikuchi T, Shirakura I, Murata T. Benzophenone Glucosides and B-Type Proanthocyanidin Dimers from Zambian Cassia abbreviata and Their Trypanocidal Activities. JOURNAL OF NATURAL PRODUCTS 2022; 85:91-104. [PMID: 34965114 DOI: 10.1021/acs.jnatprod.1c00738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Two benzophenone glucosides (1 and 2), five flavan-3-ol dimers (5-9), and 17 known compounds (3, 4, and 10-24) were identified from the bark extract of Cassia abbreviata. The chemical structures display two points of interest. First, as an unusual characteristic feature of the 1H NMR spectra of 1 and 2, the signals for the protons on glucosidic carbons C-2 are shielded as compared to those generally observed for glucosyl moieties. The geometrically optimized 3D structures derived from conformational analysis and density functional theory (DFT) calculations revealed that this shielding effect originates from intramolecular hydrogen bonds in 1 and 2. Additionally, 3-15 were identified as dimeric B-type proanthocyanidins, which have 2R,3S-absolute-configured C-rings and C-4-C-8″ linkages, as evidenced by X-ray crystallography and by NMR and ECD spectroscopy. These results suggest the structure-determining procedures for some reported dimers need to be reconsidered. The trypanocidal activities of the isolated compounds against Trypanosoma brucei brucei, T. b. gambiense, T. b. rhodesiense, T. congolense, and T. evansi were evaluated, and the active compounds were identified.
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Affiliation(s)
- Linous Munsimbwe
- Department of Veterinary Services, Ministry of Fisheries and Livestock, P.O. Box 50060, Lusaka 10101, Zambia
| | - Keisuke Suganuma
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro, Hokkaido 080-8555, Japan
| | - Yoshinobu Ishikawa
- Faculty of Pharmaceutical Sciences, Shonan University of Medical Sciences, 16-48 Kamishinano, Totsuka-ku, Yoko-hama 244-0806, Japan
| | - Kennedy Choongo
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Zambia, P.O. Box 32379, Lusaka 10101, Zambia
- School of Animal and Veterinary Sciences, College of Agriculture, Fisheries and Forestry, Fiji National University, Koronivia Campus, Suva, Fiji
| | - Takashi Kikuchi
- Rigaku Corporation, 3-9-12 Matsubara-cho, Akishima-shi, Tokyo 196-8666, Japan
| | - Izumi Shirakura
- Division of Pharmacognosy, Tohoku Medical and Pharmaceutical University, 4-1 Komatsushima 4-chome Aoba-ku, Sendai 981-8558, Japan
| | - Toshihiro Murata
- Division of Pharmacognosy, Tohoku Medical and Pharmaceutical University, 4-1 Komatsushima 4-chome Aoba-ku, Sendai 981-8558, Japan
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33
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Huang SZ, Wang Q, Yuan JZ, Cai CH, Wang H, Mándi A, Kurtán T, Dai HF, Zhao YX. Hexahydroazulene-2(1 H)-one Sesquiterpenoids with Bridged Cyclobutane, Oxetane, and Tetrahydrofuran Rings from the Stems of Daphne papyracea with α-Glycosidase Inhibitory Activity. JOURNAL OF NATURAL PRODUCTS 2022; 85:3-14. [PMID: 34935371 DOI: 10.1021/acs.jnatprod.0c01394] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Chemical investigation of an alcoholic extract from the stem of Daphne papyracea ("Xuehuagou") led to the isolation of the tetracyclic sesquiterpenoid daphnepapytone A (1), containing a unique caged skeleton with a cyclobutane ring having three tetrasubstituted chirality centers. Also isolated were new guaiane sesquiterpenoids, namely, daphnepapytones B-H (2-8), and one 1,5-diphenylpentanone 2-hydroxy-5-oxo-daphneone (9), together with 26 known compounds. The cyclic metabolites share a 5-isoprenyl-hexahydroazulene-2(1H)-one skeleton with different substitution patterns and a bridged cyclobutane, oxetane, or tetrahydrofuran ring. The planar structures and relative configuration of the new compounds were elucidated on the basis of spectroscopic analysis aided by DFT 13C NMR calculations. The absolute configurations of 1-7 were determined by X-ray single-crystal diffraction or TDDFT-ECD calculations. Daphnepapytones A and C (1 and 3), 2-hydroxy-5-oxodaphneone (9), daphnenone (10), daphneone (11), and 3-methyldaphneolone (12) showed α-glycosidase inhibitory activity, with IC50 values of 159.0, 102.3, 139.3, 43.3, 145.0, and 126.1 μM, respectively.
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Affiliation(s)
- Sheng-Zhuo Huang
- Hainan Key Laboratory for Research and Development of Natural Products from Li Folk Medicine, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agriculture Sciences, Haikou 571101, People's Republic of China
| | - Qi Wang
- Hainan Key Laboratory for Research and Development of Natural Products from Li Folk Medicine, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agriculture Sciences, Haikou 571101, People's Republic of China
- College of Tropical Crop, Hainan University, Haikou 570228, People's Republic of China
| | - Jing-Zhe Yuan
- Hainan Key Laboratory for Research and Development of Natural Products from Li Folk Medicine, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agriculture Sciences, Haikou 571101, People's Republic of China
- College of Tropical Crop, Hainan University, Haikou 570228, People's Republic of China
| | - Cai-Hong Cai
- Hainan Key Laboratory for Research and Development of Natural Products from Li Folk Medicine, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agriculture Sciences, Haikou 571101, People's Republic of China
| | - Hao Wang
- Hainan Key Laboratory for Research and Development of Natural Products from Li Folk Medicine, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agriculture Sciences, Haikou 571101, People's Republic of China
| | - Attila Mándi
- Department of Organic Chemistry, University of Debrecen, P.O.B. 400, 4002 Debrecen, Hungary
| | - Tibor Kurtán
- Department of Organic Chemistry, University of Debrecen, P.O.B. 400, 4002 Debrecen, Hungary
| | - Hao-Fu Dai
- Hainan Key Laboratory for Research and Development of Natural Products from Li Folk Medicine, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agriculture Sciences, Haikou 571101, People's Republic of China
| | - You-Xing Zhao
- Hainan Key Laboratory for Research and Development of Natural Products from Li Folk Medicine, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agriculture Sciences, Haikou 571101, People's Republic of China
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Bharadwaj VS, Westawker LP, Crowley MF. Towards Elucidating Structure–Spectra Relationships in Rhamnogalacturonan II: Computational Protocols for Accurate 13C and 1H Shifts for Apiose and Its Borate Esters. Front Mol Biosci 2022; 8:756219. [PMID: 35141275 PMCID: PMC8820409 DOI: 10.3389/fmolb.2021.756219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 11/24/2021] [Indexed: 11/13/2022] Open
Abstract
Apiose is a naturally occurring, uncommon branched-chain pentose found in plant cell walls as part of the complex polysaccharide Rhamnogalacturonan II (RG-II). The structural elucidation of the three-dimensional structure of RG-II by nuclear magnetic resonance (NMR) spectroscopy is significantly complicated by the ability of apiose to cross-link via borate ester linkages to form RG-II dimers. Here, we developed a computational approach to gain insight into the structure–spectra relationships of apio–borate complexes in an effort to complement experimental assignments of NMR signals in RG-II. Our protocol involved structure optimizations using density functional theory (DFT) followed by isotropic magnetic shielding constant calculations using the gauge-invariant atomic orbital (GIAO) approach to predict chemical shifts. We evaluated the accuracy of 23 different functional–basis set (FBS) combinations with and without implicit solvation for predicting the experimental 1H and 13C shifts of a methyl apioside and its three borate derivatives. The computed NMR predictions were evaluated on the basis of the overall shift accuracy, relative shift ordering, and the ability to distinguish between dimers and monomers. We demonstrate that the consideration of implicit solvation during geometry optimizations in addition to the magnetic shielding constant calculations greatly increases the accuracy of NMR chemical shift predictions and can correctly reproduce the ordering of the 13C shifts and yield predictions that are, on average, within 1.50 ppm for 13C and 0.12 ppm for 1H shifts for apio–borate compounds.
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35
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Aursnes M, Primdahl KG, Kaupang Å, Park JD, Seyedsayamdost MR, Nolsøe JMJ. On the Structure of Thailandene A: Synthetic Examination of the Cryptic Natural Product Aided by a Theoretical Approach. SYNTHESIS-STUTTGART 2022. [DOI: 10.1055/s-0041-1737242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
AbstractPhenotype-guided transposon mutagenesis has emerged as a valuable tool to access cryptic metabolites encoded in bacterial genomes. Recently, the method was demonstrated by inducing silent biosynthetic gene clusters in Burkholderia thailandensis. Amongst the isolated metabolic products, thailandene A exhibited promising antibiotic activity. By assignment, the linear polyenic aldehyde contained a labile motif, where an ostensible chiral secondary alcohol was interlaced in an allylic and a homoallylic constellation. Our attention was drawn to the pseudo-symmetric relationship between the heterofunctionalities, indicating the transformation of a dodecapentaenedial scaffold. Centering on an iterative cross-coupling protocol, the assigned all-E-(12R)-hydroxydodecapentaenal moiety was assembled by combining Zincke chemistry with the MIDA-attenuated Suzuki reaction developed in the Burke laboratory. Thus, according to the devised strategy, the mixed 1,2-bisborylated vinyl linchpin was consecutively functionalized with 5-bromodienal derivatives in a doubly orthogonal fashion. However, when the synthetic material was matched against the bacterial isolate, inconsistencies were observed. A re-examination of the cryptic natural product was conducted by juxtaposing analytical data from experiment and density functional theory calculations, in which hydroperoxide was evaluated as a candidate metabolite present in the bacterial isolate.
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Affiliation(s)
- Marius Aursnes
- Department of Pharmaceutical Chemistry, University of Oslo
| | | | - Åsmund Kaupang
- Department of Pharmaceutical Chemistry, University of Oslo
| | | | | | - Jens M. J. Nolsøe
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences
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36
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Steinert RM, Kasireddy C, Heikes ME, Mitchell-Koch KR. Newly identified C–H⋯O hydrogen bond in histidine. Phys Chem Chem Phys 2022; 24:19233-19251. [DOI: 10.1039/d2cp02048c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Histidine C–H bonds observed in protein structures include (clockwise from top left): myoglobin, β-lactamase, and photoactive yellow protein; calculations indicate that tautomeric/protonation state influences H-bonding ability (bottom left).
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Affiliation(s)
- Ryan M. Steinert
- Department of Chemistry and Biochemistry, Wichita State University, 1845 Fairmount Street, Wichita, KS 67260-0051, USA
| | - Chandana Kasireddy
- Department of Chemistry and Biochemistry, Wichita State University, 1845 Fairmount Street, Wichita, KS 67260-0051, USA
| | - Micah E. Heikes
- Department of Chemistry and Biochemistry, Wichita State University, 1845 Fairmount Street, Wichita, KS 67260-0051, USA
| | - Katie R. Mitchell-Koch
- Department of Chemistry and Biochemistry, Wichita State University, 1845 Fairmount Street, Wichita, KS 67260-0051, USA
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37
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de Oliveira MT, Alves JMA, Braga AAC, Wilson DJD, Barboza CA. Do Double-Hybrid Exchange-Correlation Functionals Provide Accurate Chemical Shifts? A Benchmark Assessment for Proton NMR. J Chem Theory Comput 2021; 17:6876-6885. [PMID: 34637284 DOI: 10.1021/acs.jctc.1c00604] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A benchmark density functional theory (DFT) study of 1H NMR chemical shifts for data sets comprising 200 chemical shifts, including complex natural products, has been carried out to assess the performance of DFT methods. Two new benchmark data sets, NMRH33 and NMRH148, have been established. The meta-GGA revTPSS performs remarkably well against the NMRH33 benchmark set (mean absolute deviation (MAD), 0.10 ppm; maximum deviation (max), 0.26 ppm) with the smallest MAD of all evaluated functionals. The best-performing double-hybrid density functional (DHDF), revDSD-BLYP (MAD, 0.16 ppm; max, 0.35 ppm), performs similarly to hybrid-GGA methods (e.g., mPW1PW91/6-311G(d) (MAD, 0.15 ppm; max, 0.36 ppm)), but at a considerably higher computational cost. The results indicate that currently available double-hybrid DFT methods offer no benefit over GGA (including hybrid and meta) functionals in the calculation of 1H NMR chemical shifts.
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Affiliation(s)
- Marcelo T de Oliveira
- Department of Chemistry and Physics, La Trobe Institute of Molecular Sciences, La Trobe University, Melbourne, Victoria 3086, Australia.,Chemistry Institute of São Carlos, University of São Paulo, Avenida Trabalhador São Carlense 400, 13566-590 São Carlos, São Paulo, Brazil
| | - Júlia M A Alves
- Chemistry Institute of São Carlos, University of São Paulo, Avenida Trabalhador São Carlense 400, 13566-590 São Carlos, São Paulo, Brazil
| | - Ataualpa A C Braga
- Instituto de Química, Universidade de São Paulo, Avenida Prof. Lineu Prestes 748, 05508-000 São Paulo, Brazil
| | - David J D Wilson
- Department of Chemistry and Physics, La Trobe Institute of Molecular Sciences, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Cristina A Barboza
- Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, Warsaw 02-668, Poland
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38
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Bingham JT, Etz BD, DuClos JM, Vyas S. Structure and Reactivity of Alloxan Monohydrate in the Liquid Phase. J Org Chem 2021; 86:14553-14562. [PMID: 34582209 DOI: 10.1021/acs.joc.1c01389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Alloxan is an important toxic glucose analogue used to induce diabetes in lab test animals. Once regarded as a "problem structure," the condensed-phase structure of anhydrous alloxan has largely been settled, but literature inconsistencies remain for the structure of the typically employed reagent alloxan monohydrate. Due to the criticality of structure-function relationships, we have used 1H/13C{1H} NMR, IR spectroscopy, as well as quantum mechanical (QM) calculations to probe the liquid-phase structure and reactivity of alloxan monohydrate. In protic solvents (D2O and acetic acid-d4), hydration at the C5 carbonyl of alloxan monohydrate occurs quantitatively to form the C5 gem-diol (5,5'-dihydroxybarbituric acid). In the aprotic solvent dimethyl sulfoxide (DMSO)-d6, there exists a mixture of the C5 gem-diol and planar tetraketo form of alloxan monohydrate. QM calculations explain the solvent-dependent hydration reactivity, where a solvent-assisted H-atom transfer mechanism lowers the activation energy of water addition at the C5 carbonyl by ∼16 or 27 kcal/mol in water or acetic acid, respectively, compared to the unassisted hydration reaction. Prompt recrystallization of alloxan monohydrate from boiling water does not alter the structure of the reagent. These findings probe the exact structure of alloxan monohydrate to guide future research efforts in biological sciences and in organic synthesis.
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Affiliation(s)
- Jacob T Bingham
- Department of Chemistry, Colorado School of Mines, 1012 14th Street, Golden, Colorado 80401, United States
| | - Brian D Etz
- Department of Chemistry, Colorado School of Mines, 1012 14th Street, Golden, Colorado 80401, United States
| | - Julie M DuClos
- Department of Chemistry, Colorado School of Mines, 1012 14th Street, Golden, Colorado 80401, United States
| | - Shubham Vyas
- Department of Chemistry, Colorado School of Mines, 1012 14th Street, Golden, Colorado 80401, United States
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39
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Pierens GK. A New Metric for Evaluating DFT Calculated Proton and Carbon Chemical Shifts of Natural Products and Organic Compounds. Chemphyschem 2021; 22:2207-2214. [PMID: 34546658 DOI: 10.1002/cphc.202100579] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 09/01/2021] [Indexed: 11/07/2022]
Abstract
The calculation of DFT (density functional theory) chemical shifts have become an important technique for the verification of a proposed structure. An easily calculated metric developed for proton and carbon chemical shifts of natural products and organic compounds, the calculated chemical shift index (CCSI), has been developed, which uses the deviation of each pair of calculated and experimental chemical shifts. The mean absolute deviation (MAD), which is commonly used as the goodness of fit metric for DFT calculated chemical shifts, can conceal large deviations in the calculated data. A classification strategy is also proposed for the CCSI to highlight when further assessment of the NMR data is required.
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Affiliation(s)
- Gregory K Pierens
- Centre for Advanced Imaging, The University of Queensland, St Lucia, Queensland, 4072, Australia
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40
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Phumjan T, Songthammawat P, Jongcharoenkamol J, Batsomboon P, Ruchirawat S, Ploypradith P. Substituted 9-Anthraldehydes from Dibenzocycloheptanol Epoxides via Acid-Catalyzed Epoxide Opening/Semipinacol Rearrangement. J Org Chem 2021; 86:13322-13349. [PMID: 34415157 DOI: 10.1021/acs.joc.1c01405] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Starting from benzaldehyde derivatives, the corresponding dibenzocycloheptenol could be prepared in five steps. Under both substrate (secondary vs tertiary alcohol and the substituents on the aromatic ring(s)) and condition control, the subsequent epoxidation and acid-catalyzed epoxide opening/semipinacol rearrangement/aromatization afforded the corresponding 9-anthraldehydes in good yields, up to 88% over two steps. The presence of the electron-withdrawing group(s) on the aromatic ring(s) suppressed the rate of the epoxidation while the subsequent semipinacol rearrangement step required heating; the presence of the electron-donating group(s), on the other hand, frequently led to the decomposition during the epoxidation. From the mechanistic studies, the semipinacol rearrangement of the epoxide could precede the ionization at the bisbenzylic position, yielding the aldehyde intermediate. The ensuing dehydrative aromatization led to the formation of 9-anthraldehyde. Conversely, nucleophilic addition to the aldehyde and dehydrative aromatization with concomitant loss of formic acid led to anthracene.
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Affiliation(s)
- Tanawat Phumjan
- Program in Chemical Sciences, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, 906 Khamphaeng Phet 6 Road, Laksi, Bangkok 10210, Thailand
| | - Poramate Songthammawat
- Laboratory of Medicinal Chemistry, Chulabhorn Research Institute, 54 Kamphaeng Phet 6 Road, Laksi, Bangkok, Thailand 10210
| | - Jira Jongcharoenkamol
- Program in Chemical Sciences, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, 906 Khamphaeng Phet 6 Road, Laksi, Bangkok 10210, Thailand
| | - Paratchata Batsomboon
- Laboratory of Medicinal Chemistry, Chulabhorn Research Institute, 54 Kamphaeng Phet 6 Road, Laksi, Bangkok, Thailand 10210
| | - Somsak Ruchirawat
- Program in Chemical Sciences, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, 906 Khamphaeng Phet 6 Road, Laksi, Bangkok 10210, Thailand.,Laboratory of Medicinal Chemistry, Chulabhorn Research Institute, 54 Kamphaeng Phet 6 Road, Laksi, Bangkok, Thailand 10210.,Centre of Excellence on Environmental Health and Toxicology, Ministry of Education, Bangkok 10400, Thailand
| | - Poonsakdi Ploypradith
- Program in Chemical Sciences, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, 906 Khamphaeng Phet 6 Road, Laksi, Bangkok 10210, Thailand.,Laboratory of Medicinal Chemistry, Chulabhorn Research Institute, 54 Kamphaeng Phet 6 Road, Laksi, Bangkok, Thailand 10210.,Centre of Excellence on Environmental Health and Toxicology, Ministry of Education, Bangkok 10400, Thailand
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41
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Liu X, Liu Y, Wang X, Wang T, Sun S, Wang W. Study on the molecular structure and chemical properties of the polyoxypregnane derivatives 11α-O-2-methylbutyryl-12β-O-tigloyl tenacigenin B and 11α,12β-O-ditigloyl tenacigenin B by combining experimental and theoretical methods. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2021.130350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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43
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Borges R, Colby SM, Das S, Edison AS, Fiehn O, Kind T, Lee J, Merrill AT, Merz KM, Metz TO, Nunez JR, Tantillo DJ, Wang LP, Wang S, Renslow RS. Quantum Chemistry Calculations for Metabolomics. Chem Rev 2021; 121:5633-5670. [PMID: 33979149 PMCID: PMC8161423 DOI: 10.1021/acs.chemrev.0c00901] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Indexed: 02/07/2023]
Abstract
A primary goal of metabolomics studies is to fully characterize the small-molecule composition of complex biological and environmental samples. However, despite advances in analytical technologies over the past two decades, the majority of small molecules in complex samples are not readily identifiable due to the immense structural and chemical diversity present within the metabolome. Current gold-standard identification methods rely on reference libraries built using authentic chemical materials ("standards"), which are not available for most molecules. Computational quantum chemistry methods, which can be used to calculate chemical properties that are then measured by analytical platforms, offer an alternative route for building reference libraries, i.e., in silico libraries for "standards-free" identification. In this review, we cover the major roadblocks currently facing metabolomics and discuss applications where quantum chemistry calculations offer a solution. Several successful examples for nuclear magnetic resonance spectroscopy, ion mobility spectrometry, infrared spectroscopy, and mass spectrometry methods are reviewed. Finally, we consider current best practices, sources of error, and provide an outlook for quantum chemistry calculations in metabolomics studies. We expect this review will inspire researchers in the field of small-molecule identification to accelerate adoption of in silico methods for generation of reference libraries and to add quantum chemistry calculations as another tool at their disposal to characterize complex samples.
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Affiliation(s)
- Ricardo
M. Borges
- Walter
Mors Institute of Research on Natural Products, Federal University of Rio de Janeiro, Rio de Janeiro 21941-901, Brazil
| | - Sean M. Colby
- Biological
Science Division, Pacific Northwest National
Laboratory, Richland, Washington 99352, United States
| | - Susanta Das
- Department
of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Arthur S. Edison
- Departments
of Genetics and Biochemistry and Molecular Biology, Complex Carbohydrate
Research Center and Institute of Bioinformatics, University of Georgia, Athens, Georgia 30602, United States
| | - Oliver Fiehn
- West
Coast Metabolomics Center for Compound Identification, UC Davis Genome
Center, University of California, Davis, California 95616, United States
| | - Tobias Kind
- West
Coast Metabolomics Center for Compound Identification, UC Davis Genome
Center, University of California, Davis, California 95616, United States
| | - Jesi Lee
- West
Coast Metabolomics Center for Compound Identification, UC Davis Genome
Center, University of California, Davis, California 95616, United States
- Department
of Chemistry, University of California, Davis, California 95616, United States
| | - Amy T. Merrill
- Department
of Chemistry, University of California, Davis, California 95616, United States
| | - Kenneth M. Merz
- Department
of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Thomas O. Metz
- Biological
Science Division, Pacific Northwest National
Laboratory, Richland, Washington 99352, United States
| | - Jamie R. Nunez
- Biological
Science Division, Pacific Northwest National
Laboratory, Richland, Washington 99352, United States
| | - Dean J. Tantillo
- Department
of Chemistry, University of California, Davis, California 95616, United States
| | - Lee-Ping Wang
- Department
of Chemistry, University of California, Davis, California 95616, United States
| | - Shunyang Wang
- West
Coast Metabolomics Center for Compound Identification, UC Davis Genome
Center, University of California, Davis, California 95616, United States
- Department
of Chemistry, University of California, Davis, California 95616, United States
| | - Ryan S. Renslow
- Biological
Science Division, Pacific Northwest National
Laboratory, Richland, Washington 99352, United States
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Peng GY, Kurtán T, Mándi A, He J, Cao ZY, Tang H, Mao SC, Zhang W. Neuronal Modulators from the Coral-Associated Fungi Aspergillus candidus. Mar Drugs 2021; 19:md19050281. [PMID: 34069724 PMCID: PMC8161303 DOI: 10.3390/md19050281] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/12/2021] [Accepted: 05/13/2021] [Indexed: 11/16/2022] Open
Abstract
Three new p-terphenyl derivatives, named 4″-O-methyl-prenylterphenyllin B (1) and phenylcandilide A and B (17 and 18), and three new indole-diterpene alkaloids, asperindoles E-G (22-24), were isolated together with eighteen known analogues from the fungi Aspergillus candidus associated with the South China Sea gorgonian Junceela fragillis. The structures and absolute configurations of the new compounds were elucidated on the basis of spectroscopic analysis, and DFT/NMR and TDDFT/ECD calculations. In a primary cultured cortical neuronal network, the compounds 6, 9, 14, 17, 18 and 24 modulated spontaneous Ca2+ oscillations and 4-aminopyridine hyperexcited neuronal activity. A preliminary structure-activity relationship was discussed.
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Affiliation(s)
- Gao-Yang Peng
- School of Pharmacy, Nanchang University, 461 Bayi Road, Nanchang 330006, China;
- School of Medicine, Tongji University, 1239 Si-Ping Road, Shanghai 200092, China
- School of Pharmacy, Navy Medical University, 325 Guo-He Rd., Shanghai 200433, China
| | - Tibor Kurtán
- Department of Organic Chemistry, University of Debrecen, POB 400, H-4002 Debrecen, Hungary; (T.K.); (A.M.)
| | - Attila Mándi
- Department of Organic Chemistry, University of Debrecen, POB 400, H-4002 Debrecen, Hungary; (T.K.); (A.M.)
| | - Jing He
- State Key Laboratory of Natural Medicines, Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, 639 Long-Mian Ave., Nanjing 211198, China; (J.H.); (Z.-Y.C.)
| | - Zheng-Yu Cao
- State Key Laboratory of Natural Medicines, Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, 639 Long-Mian Ave., Nanjing 211198, China; (J.H.); (Z.-Y.C.)
| | - Hua Tang
- Institute of Translational Medicine, Shanghai University, 99 Shang-Da Road, Shanghai 200444, China;
| | - Shui-Chun Mao
- School of Pharmacy, Nanchang University, 461 Bayi Road, Nanchang 330006, China;
- Correspondence: (S.-C.M.); (W.Z.)
| | - Wen Zhang
- School of Medicine, Tongji University, 1239 Si-Ping Road, Shanghai 200092, China
- School of Pharmacy, Navy Medical University, 325 Guo-He Rd., Shanghai 200433, China
- Correspondence: (S.-C.M.); (W.Z.)
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Igarashi Y, Matsuyuki Y, Yamada M, Fujihara N, Harunari E, Oku N, Karim MRU, Yang T, Yamada K, Imada C, Fukaya K, Urabe D. Structure Determination, Biosynthetic Origin, and Total Synthesis of Akazaoxime, an Enteromycin-Class Metabolite from a Marine-Derived Actinomycete of the Genus Micromonospora. J Org Chem 2021; 86:6528-6537. [PMID: 33885295 DOI: 10.1021/acs.joc.1c00358] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A new enteromycin-class antibiotic, akazaoxime (1), possessing an aldoxime functionality in place of O-methyl nitronic acid, was isolated from the cultured extract of a marine-derived actinomycete of the genus Micromonospora, along with known A-76356 (2). The structure of 1, including the absolute stereochemistry of three chiral centers, was established by comprehensive analysis of nuclear magnetic resonance (NMR) and mass spectrometry data coupled with magnetic anisotropy analysis of its phenylglycine methyl ester derivatives. The stereochemistry of 2, not determined previously, was proven to be the same as that of 1 on the basis of the similarity of their NMR and specific rotation data. Precursor feeding experiments using 13C-labeled compounds elucidated that the carbon skeletons of 1 and 2 are constructed from propionate (methylmalonate), leucine, and glycine. Establishment of the concise and flexible synthetic route to 1 enabled us to implement biological evaluation of 1 and its unnatural analogues, demonstrating weak to moderate antimicrobial activities of 1 against Gram-positive Kocuria rhizophila [minimum inhibitory concentration (MIC) of 50 μg/mL] and those of synthetic analogues against a plant pathogen Glomerella cingulata (MIC of 50 μg/mL) and a human pathogen Trichophyton rubrum (MIC of 25-50 μg/mL).
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Affiliation(s)
- Yasuhiro Igarashi
- Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Yoe Matsuyuki
- Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Masayuki Yamada
- Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Nodoka Fujihara
- Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Enjuro Harunari
- Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Naoya Oku
- Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Md Rokon Ul Karim
- Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Taehui Yang
- Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7, Konan, Minato-ku, Tokyo 108-8477, Japan
| | - Katsuhisa Yamada
- DHC Corporation, 2-7-1 minami-Azabu, Minato-ku, Tokyo 106-8571, Japan
| | - Chiaki Imada
- Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7, Konan, Minato-ku, Tokyo 108-8477, Japan
| | - Keisuke Fukaya
- Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Daisuke Urabe
- Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
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Mazurek AH, Szeleszczuk Ł, Pisklak DM. A Review on Combination of Ab Initio Molecular Dynamics and NMR Parameters Calculations. Int J Mol Sci 2021; 22:4378. [PMID: 33922192 PMCID: PMC8122754 DOI: 10.3390/ijms22094378] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/17/2021] [Accepted: 04/20/2021] [Indexed: 01/19/2023] Open
Abstract
This review focuses on a combination of ab initio molecular dynamics (aiMD) and NMR parameters calculations using quantum mechanical methods. The advantages of such an approach in comparison to the commonly applied computations for the structures optimized at 0 K are presented. This article was designed as a convenient overview of the applied parameters such as the aiMD type, DFT functional, time step, or total simulation time, as well as examples of previously studied systems. From the analysis of the published works describing the applications of such combinations, it was concluded that including fast, small-amplitude motions through aiMD has a noticeable effect on the accuracy of NMR parameters calculations.
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Affiliation(s)
- Anna Helena Mazurek
- Department of Physical Chemistry, Chair and Department of Physical Pharmacy and Bioanalysis, Faculty of Pharmacy, Doctoral School, Medical University of Warsaw, Banacha 1 Str., 02-093 Warsaw, Poland;
| | - Łukasz Szeleszczuk
- Department of Physical Chemistry, Chair and Department of Physical Pharmacy and Bioanalysis, Faculty of Pharmacy, Medical University of Warsaw, Banacha 1 Str., 02-093 Warsaw, Poland;
| | - Dariusz Maciej Pisklak
- Department of Physical Chemistry, Chair and Department of Physical Pharmacy and Bioanalysis, Faculty of Pharmacy, Medical University of Warsaw, Banacha 1 Str., 02-093 Warsaw, Poland;
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New Techniques of Structure Elucidation for Sesquiterpenes. PROGRESS IN THE CHEMISTRY OF ORGANIC NATURAL PRODUCTS 2021; 114:253-311. [PMID: 33792862 DOI: 10.1007/978-3-030-59444-2_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The most significant new techniques that have been used in the twenty-first century for the structure elucidation of sesquiterpenes and some derivatives are reviewed in this chapter. A distinctive feature of these methodologies is the combination of accurate experimental measurements with theoretical data obtained by molecular modeling calculations that allow to visualize, understand, and quantify many structural characteristics. This has been the case for NMR spectroscopy, which has expanded its potential for solving complex structural problems by means of comparison with quantum mechanical molecular models. Ab initio and density functional theory calculations of chemical shifts, coupling constants, and residual chemical shift anisotropies have played important roles in the solution of many structures of sesquiterpenes. The assignments of their absolute configurations by evaluation of calculated and experimental chiroptical properties as electronic and vibrational circular dichroism are also reviewed. This chapter also includes the use of X-ray diffraction analysis with emphasis on calculations of the Flack and Hooft parameters, which are applicable to all molecules that crystallize in non-centrosymmetric space groups. The accurate molecular models of sesquiterpenes, validated by concordance with their experimental properties, are nowadays essential for the interpretation of the effects of these natural products on biological systems.
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Study on the effect of substituents on the structure, volatility, and fluorescence of N-(Alkyl or TMS)-2-pyridinamine diethyl aluminum complexes. J Organomet Chem 2021. [DOI: 10.1016/j.jorganchem.2020.121646] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Dai SS, Yang L, Zhou L, Gao Y, Fang R, Kirillov AM, Yang L. DFT Quest of the Active Species of the Gallium-Mediated Coupling of Methylidenemalonates and Acetylenes. Inorg Chem 2021; 60:995-1006. [PMID: 33390011 DOI: 10.1021/acs.inorgchem.0c03113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this study, three different Ga-containing systems based on GaCl3, Ga2Cl6, or ionic [Ga(L)3][GaCl4]3 (L = methylidenemalonate) complex were screened to elucidate the mechanism, regioselectivity, chemoselectivity, and role of Ga mediator in the reaction between two types of acetylenes (phenylacetylene and but-1-yn-1-ylbenzene) and methylidenemalonates, i.e., the 1,2-zwitterionic precursors that are similar to intermediates derived from donor-acceptor cyclopropanes (DACs). Our DFT calculation results clearly show that the ionic gallium complex [Ga(L)3][GaCl4]3 represents the key mediator in the title reaction. After the formation of such a complex, the first reaction step is the nucleophilic addition of phenylacetylene or but-1-yn-1-ylbenzene to [Ga(L)3][GaCl4]3, generating an unstable vinyl cation intermediate. In the phenylacetylene system, this vinyl cation intermediate accepts a chlorine atom from [GaCl4]- to give E-configuration intermediate. Then, the above process occurs to other two ligands of the Ga(III) complex to furnish a final product. On the other hand, in the but-1-yn-1-ylbenzene system, the vinyl cation intermediate prefers to undergo Friedel-Crafts (F-C) alkylation to generate a five-membered ring intermediate. This process is repeated on the other two methylidenemalonate ligands, giving rise to a final cyclization product. The distortion/interaction analysis shows that in the nucleophilic addition step the distortion energy of the Ga complex part is the main factor that influences the activation energy. Furthermore, the global reactivity index (GRI) analysis indicates that the Ga-complex model has the highest electrophilicity index ω, thus leading to the lowest energy barrier among three Ga-based models. In addition, DFT results reveal that the regioselectivity (E-configuration preference) and chemoselectivity (chloration or F-C alkylation) are mainly controlled by the steric effect rather than the electronic effect. The main findings of the present work provide a new way to analyze and rationalize various Ga-mediated reactions, which might also be extrapolated to organic transformations undergoing in the presence of aluminum and indium complexes.
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Affiliation(s)
- Song-Shan Dai
- State Key Laboratory of Applied Organic Chemistry and Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China
| | - Li Yang
- State Key Laboratory of Applied Organic Chemistry and Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China
| | - Lin Zhou
- State Key Laboratory of Applied Organic Chemistry and Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China
| | - YuanYuan Gao
- State Key Laboratory of Applied Organic Chemistry and Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China
| | - Ran Fang
- State Key Laboratory of Applied Organic Chemistry and Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China.,College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an 710021, P. R. China
| | - Alexander M Kirillov
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal.,Research Institute of Chemistry, Peoples' Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya St., Moscow 117198, Russian Federation
| | - Lizi Yang
- State Key Laboratory of Applied Organic Chemistry and Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China.,College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an 710021, P. R. China
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Costa FLP, de Albuquerque ACF, Fiorot RG, Lião LM, Martorano LH, Mota GVS, Valverde AL, Carneiro JWM, dos Santos Junior FM. Structural characterisation of natural products by means of quantum chemical calculations of NMR parameters: new insights. Org Chem Front 2021. [DOI: 10.1039/d1qo00034a] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In this review, we focus in all aspects of NMR simulation of natural products, from the fundamentals to the new computational toolboxes available, combining advanced quantum chemical calculations with upstream data processing and machine learning.
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Affiliation(s)
| | - Ana C. F. de Albuquerque
- Departamento de Química Orgânica
- Instituto de Química
- Universidade Federal Fluminense
- Niterói-RJ
- Brazil
| | - Rodolfo G. Fiorot
- Departamento de Química Orgânica
- Instituto de Química
- Universidade Federal Fluminense
- Niterói-RJ
- Brazil
| | - Luciano M. Lião
- Instituto de Química
- Universidade Federal de Goiás
- 74690-900 Goiânia-GO
- Brazil
| | - Lucas H. Martorano
- Departamento de Química Orgânica
- Instituto de Química
- Universidade Federal Fluminense
- Niterói-RJ
- Brazil
| | - Gunar V. S. Mota
- Faculdade de Ciências Naturais/Instituto de Ciências Exatas e Naturais
- Universidade Federal do Pará
- Belém-PA
- Brazil
| | - Alessandra L. Valverde
- Departamento de Química Orgânica
- Instituto de Química
- Universidade Federal Fluminense
- Niterói-RJ
- Brazil
| | - José W. M. Carneiro
- Departamento de Química Inorgânica
- Instituto de Química
- Universidade Federal Fluminense
- Niterói-RJ
- Brazil
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