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Kawashima K, Lu X, Kuninobu Y, Mori T. Mechanistic insights into the role of cyclodextrin in the regioselective radical CH trifluoromethylation of aromatic compounds. J Comput Chem 2024. [PMID: 38760972 DOI: 10.1002/jcc.27430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 04/11/2024] [Accepted: 04/29/2024] [Indexed: 05/20/2024]
Abstract
The regioselective radical CH trifluoromethylation of aromatic compounds have been shown to proceed in good yield and high regioselectivity when cyclodextrin (CD) is present. Yet, the reaction mechanism and the role of CD during the reaction have remained obscure. To this end, here we performed density functional theory (DFT) calculations to the conformations obtained by semiempirical quantum mechanical molecular dynamics calculations to reveal the reaction mechanism and the role of CD in controlling regioselectivity. The results show that metal salt increases the yield but do not affect the regioselectivity, which we further confirmed by an experiment. In contrast, multiple CD-substrate complex conformations and reaction pathways were obtained, and CD was shown to contribute to improving the regioselectivity by stabilizing the intermediate state via encapsulation. The present study indicates that CDs can increase the regioselectivity by stabilizing the intermediate and product states while only marginally affecting the transition state.
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Affiliation(s)
- Kyohei Kawashima
- Institute for Materials Chemistry and Engineering, Kyushu University, Fukuoka, Japan
| | - Xu Lu
- Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
| | - Yoichiro Kuninobu
- Institute for Materials Chemistry and Engineering, Kyushu University, Fukuoka, Japan
- Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Fukuoka, Japan
| | - Toshifumi Mori
- Institute for Materials Chemistry and Engineering, Kyushu University, Fukuoka, Japan
- Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Fukuoka, Japan
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2
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Sato F, Masuda Y, Suzuki D, Hayashi T, Iwasaki T, Kim J, Matsumoto T, Maeda E. Biomechanical analysis of tendon regeneration capacity of Iberian ribbed newts following transection injury: Comparison to a mouse model. J Orthop Res 2024; 42:607-617. [PMID: 37819002 DOI: 10.1002/jor.25705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 10/04/2023] [Accepted: 10/05/2023] [Indexed: 10/13/2023]
Abstract
Adult mammals are known for their poor ability to regenerate tissues, including tendons. On the other hand, urodeles have become an important model in regenerative studies for their remarkable ability to regenerate various body parts and organs throughout life, such as limbs, retinas, or even the brain. However, little is known about their capacity to regenerate injured tendons. If newts can also repair tendons without scar formation, they may be a suitable animal model for tendon regeneration studies in other adult vertebrates. Therefore, the present study used Iberian ribbed newts to characterize mechanical and structural regeneration of tendons following transection, using tensile tests and multiphoton microscopy. A digital flexor tendon in a hindlimb was transected either partially or completely, and regenerated tendon was examined 6 and 12 weeks after the operation. Tensile strength of regenerated tendons was significantly less than normal at 6 weeks, but was remarkably recovered at 12 weeks, reaching levels comparable to those of uninjured tendons. On the other hand, mouse tendons demonstrated poor recovery of strength even after 12 weeks. Multiphoton microscopy revealed that tendon-like collagenous tissue bridges residual tendon stubs in newts, but disorganized scar-like tissue filled the injured location in mice. These findings highlight the remarkable capacity of newts to recover from tendon injury and confirm the utility of newts as a model to study tendon regeneration.
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Affiliation(s)
- Fumiya Sato
- Biomechanics Laboratory, Department of Mechanical Systems Engineering, Graduate School of Engineering, Nagoya University, Nagoya, Aichi, Japan
| | - Yu Masuda
- Biomechanics Laboratory, Department of Mechanical Systems Engineering, Graduate School of Engineering, Nagoya University, Nagoya, Aichi, Japan
| | - Daisuke Suzuki
- Department of Health Science, Hokkaido Chitose College of Rehabilitation, Chitose, Hokkaido, Japan
| | - Toshinori Hayashi
- Amphibian Research Center, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan
| | - Tomohito Iwasaki
- Department of Food Science and Human Wellness, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan
| | - Jeonghyun Kim
- Biomechanics Laboratory, Department of Mechanical Systems Engineering, Graduate School of Engineering, Nagoya University, Nagoya, Aichi, Japan
| | - Takeo Matsumoto
- Biomechanics Laboratory, Department of Mechanical Systems Engineering, Graduate School of Engineering, Nagoya University, Nagoya, Aichi, Japan
| | - Eijiro Maeda
- Biomechanics Laboratory, Department of Mechanical Systems Engineering, Graduate School of Engineering, Nagoya University, Nagoya, Aichi, Japan
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Aso R, Katsumata T, Nakamura T, Watase Y, Amezawa K, Murakami Y. Structural and electronic characterization of fluorine-doped La0.5Sr0.5CoO3-δ using electron energy-loss spectroscopy. Microscopy (Oxf) 2024; 73:22-30. [PMID: 37243701 DOI: 10.1093/jmicro/dfad031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Revised: 05/23/2023] [Accepted: 05/25/2023] [Indexed: 05/29/2023] Open
Abstract
Perovskite oxides, ABO3, are potential catalysts for the oxygen evolution reaction, which is important in the production of hydrogen as a sustainable energy resource. Optimizing the chemical composition of such oxides by substitution or doping with additional elements is an effective approach to improving the activity of such catalysts. Here, we characterized the crystal and electronic structures of fluorine-doped La0.5Sr0.5CoO3-δ particles using scanning transmission electron microscopy (STEM) and electron energy-loss spectroscopy (EELS). High-resolution STEM imaging demonstrated the formation of a disordered surface phase caused by fluorine doping. In addition, spatially resolved EELS data showed that fluorine anions were introduced into the interiors of the particles and that Co ions near the surfaces were slightly reduced by fluorine doping in conjunction with the loss of oxygen ions. Peak fitting of energy-loss near-edge structure data demonstrated an unexpected nanostructure in the vicinity of the surface. An EELS characterization comprising elemental mapping together with an energy-loss near-edge structure analysis indicated that this nanostructure could not be assigned to Co-based materials but rather to the solid electrolyte BaF2. Complementary structural and electronic characterizations using STEM and EELS as demonstrated herein evidently have the potential to play an increasingly important role in elucidating the nanostructures of functional materials.
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Affiliation(s)
- Ryotaro Aso
- Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Takuya Katsumata
- Graduate School of Engineering, Tohoku University, 6-6-1 Aramaki-Aoba, Aoba-ku, Sendai 980-8579, Japan
| | - Takashi Nakamura
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Yusuke Watase
- Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Koji Amezawa
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Yasukazu Murakami
- Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
- The Ultramicroscopy Research Center, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
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Aoki K, Sugawara-Narutaki A, Takahashi R. Polymeric Sol-Gel Transition with the Diverging Correlation Length Verified by Small-Angle X-ray Scattering. J Phys Chem Lett 2023; 14:10396-10401. [PMID: 37955630 PMCID: PMC10683071 DOI: 10.1021/acs.jpclett.3c02631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 10/28/2023] [Accepted: 11/10/2023] [Indexed: 11/14/2023]
Abstract
Sol-gel transitions of polymers are pivotal phenomena in material science, yet the critical phenomenon of structure during gelation has remained unclear. Here, we investigated the sol-gel transition of a fluorous polymer, poly(vinylidene fluoride-co-hexafluoropropylene), in a blend of two ionic liquids. This system features a quite high amount of cross-linker and binding sites with ion-dipole interactions between the cation and C-F dipoles, thereby facilitating easy exchange of the cross-links. Changing the mixing ratio of the two ionic liquids enabled tuning the ion-dipole interactions and inducing sol-gel transition. Notably, the correlation length and molar mass, obtained by small-angle X-ray scattering, diverged at the gelation point. Moreover, the derived critical exponents (ν = 0.85 ± 0.05) aligns remarkably well with the prediction from percolation theory (ν = 0.88). To our knowledge, this is the first report on the evident divergence during polymeric gelation by small-angle scattering and the verification of the critical exponents of the percolation theory.
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Affiliation(s)
- Kota Aoki
- Department of Energy Engineering,
Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan
| | - Ayae Sugawara-Narutaki
- Department of Energy Engineering,
Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan
| | - Rintaro Takahashi
- Department of Energy Engineering,
Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603, Japan
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Umeyama T, Mizutani D, Ikeda Y, Osterloh WR, Yamamoto F, Kato K, Yamakata A, Higashi M, Urakami T, Sato H, Imahori H. An emissive charge-transfer excited-state at the well-defined hetero-nanostructure interface of an organic conjugated molecule and two-dimensional inorganic nanosheet. Chem Sci 2023; 14:11914-11923. [PMID: 37920360 PMCID: PMC10619621 DOI: 10.1039/d3sc03604a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 10/03/2023] [Indexed: 11/04/2023] Open
Abstract
Precise engineering of excited-state interactions between an organic conjugated molecule and a two-dimensional semiconducting inorganic nanosheet, specifically the manipulation of charge-transfer excited (CTE) states, still remains a challenge for state-of-the-art photochemistry. Herein, we report a long-lived, highly emissive CTE state at structurally well-defined hetero-nanostructure interfaces of photoactive pyrene and two-dimensional MoS2 nanosheets via an N-benzylsuccinimide bridge (Py-Bn-MoS2). Spectroscopic measurements reveal that no charge-transfer state is formed in the ground state, but the locally-excited (LE) state of pyrene in Py-Bn-MoS2 efficiently generates an unusual emissive CTE state. Theoretical studies elucidate the interaction of MoS2 vacant orbitals with the pyrene LE state to form a CTE state that shows a distinct solvent dependence of the emission energy. This is the first example of organic-inorganic 2D hetero-nanostructures displaying mixed luminescence properties by an accurate design of the bridge structure, and therefore represents an important step in their applications for energy conversion and optoelectronic devices and sensors.
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Affiliation(s)
- Tomokazu Umeyama
- Department of Applied Chemistry, Graduate School of Engineering, University of Hyogo Himeji Hyogo 671-2280 Japan
| | - Daizu Mizutani
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University Kyoto 615-8510 Japan
| | - Yuki Ikeda
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University Kyoto 615-8510 Japan
| | - W Ryan Osterloh
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University Kyoto 615-8510 Japan
| | - Futa Yamamoto
- Department of Applied Chemistry, Graduate School of Engineering, University of Hyogo Himeji Hyogo 671-2280 Japan
| | - Kosaku Kato
- Graduate School of Natural Science and Technology, Okayama University Okayama 700-8530 Japan
| | - Akira Yamakata
- Graduate School of Natural Science and Technology, Okayama University Okayama 700-8530 Japan
| | - Masahiro Higashi
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University Kyoto 615-8510 Japan
| | - Takumi Urakami
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University Kyoto 615-8510 Japan
| | - Hirofumi Sato
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University Kyoto 615-8510 Japan
| | - Hiroshi Imahori
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University Kyoto 615-8510 Japan
- Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University Kyoto 606-8501 Japan
- Institute for Liberal Arts and Sciences (ILAS), Kyoto University Kyoto 606-8501 Japan
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Nakamura Y, Yahiro T, Fukushima A, Kataoka N, Hioki H, Nakamura K. Prostaglandin EP3 receptor-expressing preoptic neurons bidirectionally control body temperature via tonic GABAergic signaling. Sci Adv 2022; 8:eadd5463. [PMID: 36563142 PMCID: PMC9788766 DOI: 10.1126/sciadv.add5463] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 11/08/2022] [Indexed: 05/30/2023]
Abstract
The bidirectional controller of the thermoregulatory center in the preoptic area (POA) is unknown. Using rats, here, we identify prostaglandin EP3 receptor-expressing POA neurons (POAEP3R neurons) as a pivotal bidirectional controller in the central thermoregulatory mechanism. POAEP3R neurons are activated in response to elevated ambient temperature but inhibited by prostaglandin E2, a pyrogenic mediator. Chemogenetic stimulation of POAEP3R neurons at room temperature reduces body temperature by enhancing heat dissipation, whereas inhibition of them elicits hyperthermia involving brown fat thermogenesis, mimicking fever. POAEP3R neurons innervate sympathoexcitatory neurons in the dorsomedial hypothalamus (DMH) via tonic (ceaseless) inhibitory signaling. Although many POAEP3R neuronal cell bodies express a glutamatergic messenger RNA marker, their axons in the DMH predominantly release γ-aminobutyric acid (GABA), and their GABAergic terminals are increased by chronic heat exposure. These findings demonstrate that tonic GABAergic inhibitory signaling from POAEP3R neurons is a fundamental determinant of body temperature for thermal homeostasis and fever.
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Affiliation(s)
- Yoshiko Nakamura
- Department of Integrative Physiology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Takaki Yahiro
- Department of Integrative Physiology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Akihiro Fukushima
- Department of Integrative Physiology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Naoya Kataoka
- Department of Integrative Physiology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
- Nagoya University Institute for Advanced Research, Nagoya 464-8601, Japan
| | - Hiroyuki Hioki
- Department of Neuroanatomy, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Kazuhiro Nakamura
- Department of Integrative Physiology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
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Mizuta Y. Advances in Two-Photon Imaging in Plants. Plant Cell Physiol 2021; 62:1224-1230. [PMID: 34019083 PMCID: PMC8579158 DOI: 10.1093/pcp/pcab062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 03/16/2021] [Accepted: 05/20/2021] [Indexed: 05/06/2023]
Abstract
Live and deep imaging play a significant role in the physiological and biological study of organisms. Two-photon excitation microscopy (2PEM), also known as multiphoton excitation microscopy, is a fluorescent imaging technique that allows deep imaging of living tissues. Two-photon lasers use near-infrared (NIR) pulse lasers that are less invasive and permit deep tissue penetration. In this review, recent advances in two-photon imaging and their applications in plant studies are discussed. Compared to confocal microscopy, NIR 2PEM exhibits reduced plant-specific autofluorescence, thereby achieving greater depth and high-resolution imaging in plant tissues. Fluorescent proteins with long emission wavelengths, such as orange-red fluorescent proteins, are particularly suitable for two-photon live imaging in plants. Furthermore, deep- and high-resolution imaging was achieved using plant-specific clearing methods. In addition to imaging, optical cell manipulations can be performed using femtosecond pulsed lasers at the single cell or organelle level. Optical surgery and manipulation can reveal cellular communication during development. Advances in in vivo imaging using 2PEM will greatly benefit biological studies in plant sciences.
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Affiliation(s)
- Yoko Mizuta
- Institute for Advanced Research (IAR), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
- Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
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