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Patouret R, Cham N, Chiba S. Collective Synthesis of Highly Oxygenated (Furano)germacranolides Derived from Elephantopus mollis and Elephantopus tomentosus. Angew Chem Int Ed Engl 2024; 63:e202402050. [PMID: 38488804 DOI: 10.1002/anie.202402050] [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: 01/30/2024] [Indexed: 04/06/2024]
Abstract
Germacranolides, secondary metabolites produced by plants, have garnered academic and industrial interest due to their diverse and complex topology as well as a wide array of pharmacological activities. Molephantin, a highly oxygenated germacranolide isolated from medicinal plants, Elephantopus mollis and Elephantopus tomentosus, has exhibited antitumor, inflammatory, and leishmanicidal activities. Its chemical structure is based on a highly strained ten-membered macrocyclic backbone with an (E,Z)-dienone moiety, which is fused with an α-methylene-γ-butyrolactone and adorned with four successive stereogenic centers. Herein, we report the first synthesis of molephantin in 12 steps starting from readily available building blocks. The synthesis features the highly diastereoselective intermolecular Barbier allylation of the β,γ-unsaturated aldehyde with optically active 3-bromomethyl-5H-furan-2-one intermediate and ensuing Nozaki-Hiyama-Kishi (NHK) macrocyclization for the construction of the highly oxygenated ten-membered macrocyclic framework. This synthetic route enabled access to another germacranolide congener, tomenphantopin F. Furthermore, cycloisomerization of molephantin into 2-deethoxy-2β-hydroxyphantomolin could be facilitated by irradiation with ultraviolet A light (λmax=370 nm), which opened a versatile and concise access to the related furanogermacranolides such as EM-2, phantomolin, 2-O-demethyltomenphantopin C, and tomenphantopin C.
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Affiliation(s)
- Rémi Patouret
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, 637371, Singapore
| | - Ning Cham
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, 637371, Singapore
| | - Shunsuke Chiba
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, 637371, Singapore
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Starostin RO, Freidzon AY, Gromov SP. Theoretical Study of Structure and Photophysics of Homologous Series of Bis(arylydene)cycloalkanones. Int J Mol Sci 2023; 24:13362. [PMID: 37686167 PMCID: PMC10488151 DOI: 10.3390/ijms241713362] [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: 07/21/2023] [Revised: 08/10/2023] [Accepted: 08/17/2023] [Indexed: 09/10/2023] Open
Abstract
Photophysical properties of a series of bis(arylydene)cycloalkanone dyes with various donor substituents are studied using quantum chemistry. Their capacity for luminescence and nonradiative relaxation through trans-cis isomerization is related to their structure, in particular, to the donor capacity of the substituents and the degree of conjugation due to the central cycloalkanone moiety. It is shown that cyclohexanone central moiety introduces distortions and disrupts the conjugation, thus leading to a nonmonotonic change in their properties. The increasing donor capacity of the substituents causes increase in the HOMO energy (rise in the oxidation potential) and decrease in the HOMO-LUMO gap, which results in the red shift of the absorption spectra. The ability of the excited dye to relax through fluorescence or through trans-cis isomerization is governed by the height of the barrier between the Franck-Condon and S1-S0 conical intersection regions on the potential energy surface of the lowest π-π* excited state. This barrier also correlates with the donor capacity of the substituents and the degree of conjugation between the central and donor moieties. The calculated fluorescence and trans-cis isomerization rates are in good agreement with the observed fluorescence quantum yields.
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Affiliation(s)
- Roman O. Starostin
- FSRC “Crystallography and Photonics”, Photochemistry Center of RAS, Russian Academy of Sciences, Novatorov Str. 7A-1, Moscow 119421, Russia; (R.O.S.); (S.P.G.)
- Department of Chemistry, M. V. Lomonosov Moscow State University, Leninskie Gory 1-3, Moscow 119991, Russia
| | - Alexandra Ya. Freidzon
- Institute of Nanoengineering in Electronics, Spintronics and Photonics, National Research Nuclear University MEPhI, Kashirskoye Shosse, 31, Moscow 115409, Russia
- Faculty of Chemistry, Molecular Chemistry and Materials Science, Weizmann Institute of Science, 234 Herzl Street, P.O. Box 26, Rehovot 7610001, Israel
| | - Sergey P. Gromov
- FSRC “Crystallography and Photonics”, Photochemistry Center of RAS, Russian Academy of Sciences, Novatorov Str. 7A-1, Moscow 119421, Russia; (R.O.S.); (S.P.G.)
- Department of Chemistry, M. V. Lomonosov Moscow State University, Leninskie Gory 1-3, Moscow 119991, Russia
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Fomina MV, Freidzon AY, Kuz’mina LG, Moiseeva AA, Starostin RO, Kurchavov NA, Nuriev VN, Gromov SP. Synthesis, Structure and Photochemistry of Dibenzylidenecyclobutanones. Molecules 2022; 27:7602. [PMID: 36364429 PMCID: PMC9653593 DOI: 10.3390/molecules27217602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 10/21/2022] [Accepted: 10/29/2022] [Indexed: 09/10/2023] Open
Abstract
A series of symmetrical dibenzylidene derivatives of cyclobutanone were synthesized with the goal of studying the physicochemical properties of cross-conjugated dienones (ketocyanine dyes). The structures of the products were established and studied by X-ray diffraction and by NMR and electronic spectroscopy. All the products had E,E-geometry. The oxidation and reduction potentials of the dienones were determined by cyclic voltammetry. The potentials were shown to depend on the nature, position, and number of substituents in the benzene rings. A linear correlation was found between the difference of the electrochemical oxidation and reduction potentials and the energy of the long-wavelength absorption maximum. This correlation can be employed to analyze the properties of other compounds of this type. Quantum chemistry was used to explain the observed regularities in the electrochemistry, absorption, and fluorescence of the dyes. The results are in good agreement with the experimental redox potentials and spectroscopy data.
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Affiliation(s)
- Marina V. Fomina
- Photochemistry Center of RAS, FSRC “Crystallography and Photonics”, Russian Academy of Sciences, Novatorov Str. 7A-1, 119421 Moscow, Russia
| | - Alexandra Y. Freidzon
- Photochemistry Center of RAS, FSRC “Crystallography and Photonics”, Russian Academy of Sciences, Novatorov Str. 7A-1, 119421 Moscow, Russia
| | - Lyudmila G. Kuz’mina
- N.S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninskiy Prosp. 31, 119991 Moscow, Russia
| | - Anna A. Moiseeva
- Department of Chemistry, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Roman O. Starostin
- Department of Chemistry, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Nikolai A. Kurchavov
- Photochemistry Center of RAS, FSRC “Crystallography and Photonics”, Russian Academy of Sciences, Novatorov Str. 7A-1, 119421 Moscow, Russia
| | - Vyacheslav N. Nuriev
- Photochemistry Center of RAS, FSRC “Crystallography and Photonics”, Russian Academy of Sciences, Novatorov Str. 7A-1, 119421 Moscow, Russia
- Department of Chemistry, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Sergey P. Gromov
- Photochemistry Center of RAS, FSRC “Crystallography and Photonics”, Russian Academy of Sciences, Novatorov Str. 7A-1, 119421 Moscow, Russia
- Department of Chemistry, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia
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Fomina MV, Vatsadze SZ, Freidzon AY, Kuz’mina LG, Moiseeva AA, Starostin RO, Nuriev VN, Gromov SP. Structure-Property Relationships of Dibenzylidenecyclohexanones. ACS OMEGA 2022; 7:10087-10099. [PMID: 35382345 PMCID: PMC8973102 DOI: 10.1021/acsomega.1c06129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 02/23/2022] [Indexed: 06/14/2023]
Abstract
A series of symmetrical dibenzylidene derivatives of cyclohexanone were synthesized with the goal of studying the physicochemical properties of cross-conjugated dienones (ketocyanine dyes). The structures of the products were established and studied by X-ray diffraction, NMR spectroscopy, and electronic spectroscopy. All products had the E,E-geometry. The oxidation and reduction potentials of the dienones were determined by cyclic voltammetry. The potentials were shown to depend on the nature, position, and number of substituents in the benzene rings. A linear correlation was found between the difference of the electrochemical oxidation and reduction potentials and the energy of the long-wavelength absorption maximum. This correlation can be employed to analyze the properties of other compounds of this type. The frontier orbital energies and the vertical absorption and emission transitions were calculated using quantum chemistry. The results are in good agreement with experimental redox potentials and spectroscopic data.
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Affiliation(s)
- Marina V. Fomina
- Photochemistry
Center of RAS, FSRC “Crystallography and Photonics”,
Russian Academy of Sciences, Novatorov str. 7A-1, Moscow 119421, Russian Federation
| | - Sergey Z. Vatsadze
- Department
of Chemistry, M.V. Lomonosov Moscow State
University, Moscow 119991, Russian Federation
| | - Alexandra Ya. Freidzon
- Photochemistry
Center of RAS, FSRC “Crystallography and Photonics”,
Russian Academy of Sciences, Novatorov str. 7A-1, Moscow 119421, Russian Federation
| | - Lyudmila G. Kuz’mina
- N.S.
Kurnakov Institute of General and Inorganic Chemistry, Russian Academy
of Sciences, Leninskiy prosp. 31, Moscow 119991, Russian Federation
| | - Anna A. Moiseeva
- Department
of Chemistry, M.V. Lomonosov Moscow State
University, Moscow 119991, Russian Federation
| | - Roman O. Starostin
- Department
of Chemistry, M.V. Lomonosov Moscow State
University, Moscow 119991, Russian Federation
| | - Vyacheslav N. Nuriev
- Photochemistry
Center of RAS, FSRC “Crystallography and Photonics”,
Russian Academy of Sciences, Novatorov str. 7A-1, Moscow 119421, Russian Federation
- Department
of Chemistry, M.V. Lomonosov Moscow State
University, Moscow 119991, Russian Federation
| | - Sergey P. Gromov
- Photochemistry
Center of RAS, FSRC “Crystallography and Photonics”,
Russian Academy of Sciences, Novatorov str. 7A-1, Moscow 119421, Russian Federation
- Department
of Chemistry, M.V. Lomonosov Moscow State
University, Moscow 119991, Russian Federation
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