1
|
Knaack JIH, Meier C. Out of the Dark, into the Light: Metabolic Fluorescent Labeling of Nucleic Acids. ChemMedChem 2024:e202400160. [PMID: 38712684 DOI: 10.1002/cmdc.202400160] [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: 02/29/2024] [Revised: 05/02/2024] [Accepted: 05/06/2024] [Indexed: 05/08/2024]
Abstract
This review outlines recent advances in live-cell imaging techniques for nucleic acids. We describe the evolution of these methods, particularly highlighting the development of metabolic labeling approaches compatible with living systems using fluorescence-based labeling.
Collapse
Affiliation(s)
- J Iven H Knaack
- Department of Chemistry, Faculty of Sciences, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| | - Chris Meier
- Department of Chemistry, Faculty of Sciences, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| |
Collapse
|
2
|
Copp W, Karimi A, Yang T, Guarné A, Luedtke NW. Fluorescent molecular rotors detect O6-methylguanine dynamics and repair in duplex DNA. Chem Commun (Camb) 2024; 60:1156-1159. [PMID: 38190113 DOI: 10.1039/d3cc04782b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Alkylation at the O6 position of guanine is a common and highly mutagenic form of DNA damage. Direct repair of O6-alkylguanines by the "suicide" enzyme O6-methylguanine DNA methyltransferase (MGMT, AGT, AGAT) maintains genome stability and inhibits carcinogenesis. In this study, a fluorescent analogue of thymidine containing trans-stilbene (tsT) is quenched by O6-methylguanine residues in the opposite strand of DNA by molecular dynamics that propagate through the duplex with as much as ∼9 Å of separation. Increased fluorescence of tsT or the cytosine analogue tsC resulting from MGMT-mediated DNA repair were distinguishable from non-covalent DNA-protein binding following protease digest. To our knowledge, this is the first study utilizing molecular rotor base analogues to detect DNA damage and repair activities in duplex DNA.
Collapse
Affiliation(s)
- William Copp
- Department of Chemistry, McGill University, H3A-0B8 Montreal, Canada
- Centre de Recherche en Biologie Structural, McGill University, H3G 0B1 Montreal, Canada
| | - Ashkan Karimi
- Department of Chemistry, McGill University, H3A-0B8 Montreal, Canada
- Centre de Recherche en Biologie Structural, McGill University, H3G 0B1 Montreal, Canada
| | - Tianxiao Yang
- Centre de Recherche en Biologie Structural, McGill University, H3G 0B1 Montreal, Canada
- Department of Biochemistry, McGill University, H3G 1Y6 Montreal, Canada
| | - Alba Guarné
- Centre de Recherche en Biologie Structural, McGill University, H3G 0B1 Montreal, Canada
- Department of Biochemistry, McGill University, H3G 1Y6 Montreal, Canada
| | - Nathan W Luedtke
- Department of Chemistry, McGill University, H3A-0B8 Montreal, Canada
- Centre de Recherche en Biologie Structural, McGill University, H3G 0B1 Montreal, Canada
- Department of Pharmacology and Therapeutics, McGill University, H3A-1A3 Montreal, Canada
| |
Collapse
|
3
|
Sterrenberg VT, Stalling D, Knaack JIH, Soh TK, Bosse JB, Meier C. A TriPPPro-Nucleotide Reporter with Optimized Cell-Permeable Dyes for Metabolic Labeling of Cellular and Viral DNA in Living Cells. Angew Chem Int Ed Engl 2023; 62:e202308271. [PMID: 37435767 DOI: 10.1002/anie.202308271] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 07/04/2023] [Accepted: 07/07/2023] [Indexed: 07/13/2023]
Abstract
The metabolic labeling of nucleic acids in living cells is highly desirable to track the dynamics of nucleic acid metabolism in real-time and has the potential to provide novel insights into cellular biology as well as pathogen-host interactions. Catalyst-free inverse electron demand Diels-Alder reactions (iEDDA) with nucleosides carrying highly reactive moieties such as axial 2-trans-cyclooctene (2TCOa) would be an ideal tool to allow intracellular labeling of DNA. However, cellular kinase phosphorylation of the modified nucleosides is needed after cellular uptake as triphosphates are not membrane permeable. Unfortunately, the narrow substrate window of most endogenous kinases limits the use of highly reactive moieties. Here, we apply our TriPPPro (triphosphate pronucleotide) approach to directly deliver a highly reactive 2TCOa-modified 2'-deoxycytidine triphosphate reporter into living cells. We show that this nucleoside triphosphate is metabolically incorporated into de novo synthesized cellular and viral DNA and can be labeled with highly reactive and cell-permeable fluorescent dye-tetrazine conjugates via iEDDA to visualize DNA in living cells directly. Thus, we present the first comprehensive method for live-cell imaging of cellular and viral nucleic acids using a two-step labeling approach.
Collapse
Affiliation(s)
- Vincente T Sterrenberg
- Department of Chemistry, Faculty of Sciences, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| | - Dörte Stalling
- CSSB Centre for Structural Systems Biology, Notkestraße 85, Building 15, 22607, Hamburg, Germany
- Institute of Virology, Hannover Medical School (MHH), 30625, Hannover, Germany
- Leibniz Institute of Virology (LIV), 20251, Hamburg, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, 30625, Hannover, Germany
| | - J Iven H Knaack
- Department of Chemistry, Faculty of Sciences, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| | - Timothy K Soh
- CSSB Centre for Structural Systems Biology, Notkestraße 85, Building 15, 22607, Hamburg, Germany
- Institute of Virology, Hannover Medical School (MHH), 30625, Hannover, Germany
- Leibniz Institute of Virology (LIV), 20251, Hamburg, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, 30625, Hannover, Germany
| | - Jens B Bosse
- CSSB Centre for Structural Systems Biology, Notkestraße 85, Building 15, 22607, Hamburg, Germany
- Institute of Virology, Hannover Medical School (MHH), 30625, Hannover, Germany
- Leibniz Institute of Virology (LIV), 20251, Hamburg, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, 30625, Hannover, Germany
| | - Chris Meier
- Department of Chemistry, Faculty of Sciences, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| |
Collapse
|
4
|
Chandankar SS, Kondhare D, Leonard P, Seela F. Purine DNA Constructs Designed to Expand the Genetic Code: Functionalization, Impact of Ionic Forms, and Molecular Recognition of 7-Deazaxanthine-7-Deazapurine-2,6-diamine Base Pairs and Their Purine Counterparts. J Org Chem 2023; 88:13149-13168. [PMID: 37669119 DOI: 10.1021/acs.joc.3c01370] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2023]
Abstract
Purine DNA represents an alternative pairing system formed by two purines in the base pair with the recognition elements of Watson-Crick DNA. Base functionalization of 7-deaza-2'-deoxyxanthosine with ethynyl and octadiynyl residues led to clickable side chain derivatives with short and long linker arms. As complementary bases, purine-2,6-diamine or 7-deazapurine-2,6-diamine 2'-deoxyribonucleosides were used. 7-Deaza-7-iodo-2'-deoxyxanthosine served as a starting material for Sonogashira cross-coupling and the p-nitrophenylethyl group for base protection. Phosphoramidite building blocks for DNA synthesis were prepared. Oligonucleotides containing single modifications or runs of three purine base pairs embedded in 12-mer Watson-Crick DNA were synthesized and hybridized with complementary strands with purine- or 7-deazapurine-2,6-diamine located opposite to the xanthine derivatives. The stability of base pairs was evaluated in a comparative study on the basis of DNA melting experiments and Tm values. As 7-deazaxanthine and xanthine nucleosides form anionic forms at neutral pH, duplex stability became pK-dependent, and the system with 7-deazapurine displayed a significant higher stability as that containing xanthine. Alkynyl side chains are well accommodated in the purine-purine helix. Click adducts with pyrene showed that short linker arms destabilize duplexes, whereas long linkers increase duplex stability. CD and fluorescence measurements provide further insights into purine-purine base pairing.
Collapse
Affiliation(s)
- Somnath Shivaji Chandankar
- Laboratory of Bioorganic Chemistry and Chemical Biology, Center for Nanotechnology, Heisenbergstrasse 11, 48149 Münster, Germany
| | - Dasharath Kondhare
- Laboratory of Bioorganic Chemistry and Chemical Biology, Center for Nanotechnology, Heisenbergstrasse 11, 48149 Münster, Germany
| | - Peter Leonard
- Laboratory of Bioorganic Chemistry and Chemical Biology, Center for Nanotechnology, Heisenbergstrasse 11, 48149 Münster, Germany
| | - Frank Seela
- Laboratory of Bioorganic Chemistry and Chemical Biology, Center for Nanotechnology, Heisenbergstrasse 11, 48149 Münster, Germany
- Laboratorium für Organische und Bioorganische Chemie, Institut für Chemie neuer Materialien, Universität Osnabrück, Barbarastrasse 7, 49069 Osnabrück, Germany
| |
Collapse
|
5
|
Spampinato A, Kužmová E, Pohl R, Sýkorová V, Vrábel M, Kraus T, Hocek M. trans-Cyclooctene- and Bicyclononyne-Linked Nucleotides for Click Modification of DNA with Fluorogenic Tetrazines and Live Cell Metabolic Labeling and Imaging. Bioconjug Chem 2023. [PMID: 36972479 PMCID: PMC10119924 DOI: 10.1021/acs.bioconjchem.3c00064] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
Abstract
A series of 2'-deoxyribonucleoside triphosphates (dNTPs) bearing 2- or 4-linked trans-cyclooctene (TCO) or bicyclononyne (BCN) tethered through a shorter propargylcarbamate or longer triethyleneglycol-based spacer were designed and synthesized. They were found to be good substrates for KOD XL DNA polymerase for primer extension enzymatic synthesis of modified oligonucleotides. We systematically tested and compared the reactivity of TCO- and BCN-modified nucleotides and DNA with several fluorophore-containing tetrazines in inverse electron-demand Diels-Alder (IEDDA) click reactions to show that the longer linker is crucial for efficient labeling. The modified dNTPs were transported into live cells using the synthetic transporter SNTT1, incubated for 1 h, and then treated with tetrazine conjugates. The PEG3-linked 4TCO and BCN nucleotides showed efficient incorporation into genomic DNA and good reactivity in the IEDDA click reaction with tetrazines to allow staining of DNA and imaging of DNA synthesis in live cells within time periods as short as 15 min. The BCN-linked nucleotide in combination with TAMRA-linked (TAMRA = carboxytetramethylrhodamine) tetrazine was also efficiently used for staining of DNA for flow cytometry. This methodology is a new approach for in cellulo metabolic labeling and imaging of DNA synthesis which is shorter, operationally simple, and overcomes several problems of previously used methods.
Collapse
Affiliation(s)
- Ambra Spampinato
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo Namesti 2, Prague 6 CZ-16610, Czech Republic
- Department of Organic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 8, Prague 2 12843, Czech Republic
| | - Erika Kužmová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo Namesti 2, Prague 6 CZ-16610, Czech Republic
| | - Radek Pohl
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo Namesti 2, Prague 6 CZ-16610, Czech Republic
| | - Veronika Sýkorová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo Namesti 2, Prague 6 CZ-16610, Czech Republic
| | - Milan Vrábel
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo Namesti 2, Prague 6 CZ-16610, Czech Republic
| | - Tomáš Kraus
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo Namesti 2, Prague 6 CZ-16610, Czech Republic
| | - Michal Hocek
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo Namesti 2, Prague 6 CZ-16610, Czech Republic
- Department of Organic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 8, Prague 2 12843, Czech Republic
| |
Collapse
|
6
|
Dranchak PK, Oliphant E, Queme B, Lamy L, Wang Y, Huang R, Xia M, Tao D, Inglese J. In vivo quantitative high-throughput screening for drug discovery and comparative toxicology. Dis Model Mech 2023; 16:dmm049863. [PMID: 36786055 PMCID: PMC10067442 DOI: 10.1242/dmm.049863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 02/01/2023] [Indexed: 02/15/2023] Open
Abstract
Quantitative high-throughput screening (qHTS) pharmacologically evaluates chemical libraries for therapeutic uses, toxicological risk and, increasingly, for academic probe discovery. Phenotypic high-throughput screening assays interrogate molecular pathways, often relying on cell culture systems, historically less focused on multicellular organisms. Caenorhabditis elegans has served as a eukaryotic model organism for human biology by virtue of genetic conservation and experimental tractability. Here, a paradigm enabling C. elegans qHTS using 384-well microtiter plate laser-scanning cytometry is described, in which GFP-expressing organisms revealing phenotype-modifying structure-activity relationships guide subsequent life-stage and proteomic analyses, and Escherichia coli bacterial ghosts, a non-replicating nutrient source, allow compound exposures over two life cycles, mitigating bacterial overgrowth complications. We demonstrate the method with libraries of anti-infective agents, or substances of toxicological concern. Each was tested in seven-point titration to assess the feasibility of nematode-based in vivo qHTS, and examples of follow-up strategies were provided to study organism-based chemotype selectivity and subsequent network perturbations with a physiological impact. We anticipate that this qHTS approach will enable analysis of C. elegans orthologous phenotypes of human pathologies to facilitate drug library profiling for a range of therapeutic indications.
Collapse
Affiliation(s)
- Patricia K. Dranchak
- Department of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Erin Oliphant
- Department of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Bryan Queme
- Department of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Laurence Lamy
- Department of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Yuhong Wang
- Department of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Ruili Huang
- Department of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Menghang Xia
- Department of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Dingyin Tao
- Department of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - James Inglese
- Department of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
- Metabolic Medicine Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20817, USA
| |
Collapse
|
7
|
Meher S, Gade CR, Sharma NK. Tropolone-Conjugated DNA: A Fluorescent Thymidine Analogue Exhibits Solvatochromism, Enzymatic Incorporation into DNA and HeLa Cell Internalization. Chembiochem 2023; 24:e202200732. [PMID: 36510378 DOI: 10.1002/cbic.202200732] [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: 12/09/2022] [Accepted: 12/12/2022] [Indexed: 12/14/2022]
Abstract
Tropolone is a non-benzenoid aromatic scaffold with unique photophysical and metal-chelating properties. Recently, it has been conjugated with DNA, and the photophysical properties of this conjugate have been explored. Tropolonyl-deoxyuridine (tr-dU) is a synthetic fluorescent DNA nucleoside analogue that exhibits pH-dependent emissions. However, its solvent-dependent fluorescence properties are unexplored owing to its poor solubility in most organic solvents. It would be interesting to incorporate it into DNA primer enzymatically. This report describes the solvent-dependent fluorescence properties of the silyl-derivative, and enzymatic incorporation of its triphosphate analogue. For practical use, its cell-internalization and cytotoxicity are also explored. tr-dU nucleoside was found to be a potential analogue to design DNA probes and can be explored for various therapeutic applications in the future.
Collapse
Affiliation(s)
- Sagarika Meher
- School of Chemical Sciences, National Institute of Science Education and Research (NISER) Bhubaneswar, Jatani, 752050, Odisha, India.,Homi Bhabha National Institute (HBNI), Training School Complex, Anushaktinagar, Mumbai, 400094, India
| | - Chandrasekhar Reddy Gade
- School of Chemical Sciences, National Institute of Science Education and Research (NISER) Bhubaneswar, Jatani, 752050, Odisha, India.,Homi Bhabha National Institute (HBNI), Training School Complex, Anushaktinagar, Mumbai, 400094, India
| | - Nagendra K Sharma
- School of Chemical Sciences, National Institute of Science Education and Research (NISER) Bhubaneswar, Jatani, 752050, Odisha, India.,Homi Bhabha National Institute (HBNI), Training School Complex, Anushaktinagar, Mumbai, 400094, India
| |
Collapse
|
8
|
Kuznetsova VE, Shershov VE, Guseinov TO, Miftakhov RA, Solyev PN, Novikov RA, Levashova AI, Zasedatelev AS, Lapa SA, Chudinov AV. Synthesis of Cy5-Labelled C5-Alkynyl-modified cytidine triphosphates via Sonogashira coupling for DNA labelling. Bioorg Chem 2023; 131:106315. [PMID: 36528924 DOI: 10.1016/j.bioorg.2022.106315] [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: 10/04/2022] [Revised: 11/15/2022] [Accepted: 12/05/2022] [Indexed: 12/14/2022]
Abstract
New applications of palladium-catalyzed Sonogashira-type cross-coupling reaction between C5-halogenated 2'-deoxycytidine-5'-monophosphate and novel cyanine dyes with a terminal alkyne group have been developed. The present methodology allows to synthesize of fluorescently labeled C5-nucleoside triphosphates with different acetylene linkers between the fluorophore and pyrimidine base in good to excellent yields under mild reaction conditions. Modified 2'-deoxycytidine-5'-triphosphates were shown to be good substrates for DNA polymerases and were incorporated into the DNA by polymerase chain reaction.
Collapse
Affiliation(s)
- Viktoriya E Kuznetsova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia.
| | - Valeriy E Shershov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Teimur O Guseinov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Rinat A Miftakhov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Pavel N Solyev
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Roman A Novikov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Anna I Levashova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Alexander S Zasedatelev
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Sergey A Lapa
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Alexander V Chudinov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia.
| |
Collapse
|
9
|
Kuba M, Pohl R, Kraus T, Hocek M. Nucleotides Bearing Red Viscosity-Sensitive Dimethoxy-Bodipy Fluorophore for Enzymatic Incorporation and DNA Labeling. Bioconjug Chem 2023; 34:133-139. [PMID: 36519639 DOI: 10.1021/acs.bioconjchem.2c00547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Nucleosides and 2'-deoxyribonucleoside triphosphates (dNTPs) bearing 3,3'-dimethoxy-2,2'-diphenyl-6-(4-hydroxyphenyl)-bodipy fluorophore attached through a propargyl or propargyl-triethylene glycol linker to position 5 of 2'-deoxycytidine were designed and synthesized. They exerted bright red fluorescence and good sensitivity to viscosity changing their lifetime from 1.6 to 4.5 ns. The modifed dNTPs were substrates for DNA polymerases and were used in enzymatic synthesis of labeled DNA through primer extension. The modified DNA probes served as viscosity sensors responding to protein binding by changes of lifetime. The nucleotide with longer linker (dCpegMOBTP) was transported to live cells and incorporated into the genomic DNA, which can be useful for staining of DNA and imaging of DNA synthesis.
Collapse
Affiliation(s)
- Miroslav Kuba
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nam. 2, CZ-16000 Prague 6, Czech Republic.,Department of Organic Chemistry, Faculty of Science, Charles University, Hlavova 8, CZ-12843 Prague 2, Czech Republic
| | - Radek Pohl
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nam. 2, CZ-16000 Prague 6, Czech Republic
| | - Tomáš Kraus
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nam. 2, CZ-16000 Prague 6, Czech Republic
| | - Michal Hocek
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nam. 2, CZ-16000 Prague 6, Czech Republic.,Department of Organic Chemistry, Faculty of Science, Charles University, Hlavova 8, CZ-12843 Prague 2, Czech Republic
| |
Collapse
|