2024/03/25 更新

写真a

アマイケ カズマ
天池 一真
AMAIKE Kazuma
所属
物質科学国際研究センター 助教
大学院担当
大学院理学研究科
職名
助教
外部リンク

学位 1

  1. 博士(理学) ( 2016年3月   名古屋大学 ) 

 

論文 22

  1. Nickel/Photoredox-Catalyzed Decarboxylative Coupling of Aryl Bromides with N -Protected Glycine as an Aminomethyl Source

    Jung, JHY; Kinoshita, T; Makihara, Y; Sakakibara, Y; Amaike, K; Murakami, K; Itami, K

    SYNLETT   35 巻 ( 03 ) 頁: 337 - 341   2024年2月

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    出版者・発行元:Synlett  

    Benzylamines are important scaffolds that are ubiquitously found in various bioactive molecules. Among the benzylamine derivatives, primary benzylamines (ArCH2NH2) are regarded as valuable building blocks for pharmaceuticals. Herein, we report decarboxylative aminomethylation of aryl bromides with N-protected glycine under nickel/photoredox-catalyzed conditions. The corresponding products can be easily deprotected under acidic conditions to give primary benzylamines.

    DOI: 10.1055/s-0041-1738444

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  2. C-H arylation enables synthesis of imidazole-4-carboxamide (ICA) based fairy chemicals with plant growth-promoting activity

    Ueda, A; Amaike, K; Shirotani, Y; Ito, H; Warstat, R; Choi, JH; Kawagishi, H; Itami, K

    CANADIAN JOURNAL OF CHEMISTRY   101 巻 ( 7 ) 頁: 449 - 452   2023年7月

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    掲載種別:研究論文(学術雑誌)   出版者・発行元:Canadian Journal of Chemistry  

    Imidazole-4-carboxamide (ICA), which is one of the groups of “fairy chemicals” (FCs) that cause the fairy ring phenomena, has plant growth inhibitory activity. FCs have the potential as candidates for a new family of plant hormones as they have been found endogenously in all plant species tested and show growth-regulating activities against the plants. While basic research on FCs is progressing, they are also expected to be applied not only to agrochemicals but also as pharmaceuticals. Derivatization of one of the FCs, 2-azahypoxanthine, and the structure-activity relationship (SAR) studies have clarified its activity as a plant growth promoter. Yet, ICA has not been derivatized at all and SAR regarding its activity remains unknown. In this study, we synthesized the derivatives of ICA by direct C-H arylation of ICA precursors and evaluated its activity in rice. The 12 total compounds including the arylated ICAs and their precursors were evaluated for root and shoot elongation in rice, resulting in the discovery that a number of compounds unexpectedly have an elongation activity in the root and shoot.

    DOI: 10.1139/cjc-2022-0256

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  3. Development of a novel PET ligand, [<SUP>11</SUP>C]GO289 targeting CK2 expressed in the brain

    Ogata, A; Yamada, T; Hattori, S; Ikenuma, H; Abe, J; Tada, M; Ichise, M; Suzuki, M; Ito, K; Kato, T; Amaike, K; Hirota, T; Kakita, A; Itami, K; Kimura, Y

    BIOORGANIC & MEDICINAL CHEMISTRY LETTERS   90 巻   頁: 129327   2023年6月

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    記述言語:英語   出版者・発行元:Bioorganic and Medicinal Chemistry Letters  

    Positron emission tomography (PET) is a powerful imaging tool that enables early in vivo detection of Alzheimer's disease (AD). For this purpose, various PET ligands have been developed to image β-amyloid and tau protein aggregates characteristically found in the brain of AD patients. In this study, we initiated to develop another type of PET ligand that targets protein kinase CK2 (formerly termed as casein kinase II), because its expression level is known to be altered in postmortem AD brains. CK2 is a serine/threonine protein kinase, an important component of cellular signaling pathways that control cellular degeneration. In AD, the CK2 level in the brain is thought to be elevated by its involvement in both phosphorylation of proteins such as tau and neuroinflammation. Decreased CK2 activity and expression levels lead to β-amyloid accumulation. In addition, since CK2 also contributes to the phosphorylation of tau protein, the expression level and activity of CK2 is expected to undergo significant changes during the progression of AD pathology. Furthermore, CK2 could act as a potential target for modulating the inflammatory response in AD. Therefore, PET imaging targeting CK2 expressed in the brain could be a useful another imaging biomarker for AD. We synthesized and radiolabeled a CK2 inhibitor, [11C]GO289, in high yields from its precursor and [11C]methyl iodide under basic conditions. On autoradiography, [11C]GO289 specifically bound to CK2 in both rat and human brain sections. On baseline PET imaging, this ligand entered and rapidly washed out of the rat brain with its peak activity rather being small (SUV < 1.0). However, on blocking, there was no detectable CK2 specific binding signal. Thus, [11C]GO289 may be useful in vitro but not so in vivo in its current formulation. The lack of detectable specific binding signal in the latter may be due to a relatively high component of nonspecific binding signal in the overall rather weak PET signal, or it may also be related to the known fact that ATP can competitively binds to subunits of CK2, reducing its availability for this ligand. In the future, it will be necessary for PET imaging of CK2 to try out different non-ATP competitive formulations of CK2 inhibitor that can also provide significantly higher in vivo brain penetration.

    DOI: 10.1016/j.bmcl.2023.129327

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  4. Revisiting PFA-mediated tissue fixation chemistry: FixEL enables trapping of small molecules in the brain to visualize their distribution changes

    Nonaka Hiroshi, Mino Takeharu, Sakamoto Seiji, Oh Jae Hoon, Watanabe Yu, Ishikawa Mamoru, Tsushima Akihiro, Amaike Kazuma, Kiyonaka Shigeki, Tamura Tomonori, Radu Aricescu A., Kakegawa Wataru, Miura Eriko, Yuzaki Michisuke, Hamachi Itaru

    Chem   9 巻 ( 2 ) 頁: 523 - 540   2023年2月

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    記述言語:英語  

    Various small molecules have been used as functional probes for tissue imaging in medical diagnosis and pharmaceutical drugs for disease treatment. The spatial distribution, target selectivity, and diffusion/excretion kinetics of small molecules in structurally complicated specimens are critical for function. However, robust methods for precisely evaluating these parameters in the brain have been limited. Herein, we report a new method termed “fixation-driven chemical cross-linking of exogenous ligands (FixEL), ” which traps and images exogenously administered molecules of interest (MOIs) in complex tissues. This method relies on protein-MOI interactions and chemical cross-linking of amine-tethered MOI with paraformaldehyde used for perfusion fixation. FixEL is used to obtain images of the distribution of the small molecules, which addresses selective/nonselective binding to proteins, time-dependent localization changes, and diffusion/retention kinetics of MOIs such as the scaffold of PET tracer derivatives or drug-like small molecules.

    CiNii Research

  5. Revisiting PFA-mediated tissue fixation chemistry:<i> FixEL</i> enables trapping of small molecules in the brain to visualize their distribution changes

    Nonaka Hiroshi, Mino Takeharu, Sakamoto Seiji, Oh Jae Hoon, Watanabe Yu, Ishikawa Mamoru, Tsushima Akihiro, Amaike Kazuma, Kiyonaka Shigeki, Tamura Tomonori, Aricescu A. Radu, Kakegawa Wataru, Miura Eriko, Yuzaki Michisuke, Hamachi Itaru

    CHEM   9 巻 ( 2 ) 頁: 523 - 540   2023年2月

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    出版者・発行元:Chem  

    Various small molecules have been used as functional probes for tissue imaging in medical diagnosis and pharmaceutical drugs for disease treatment. The spatial distribution, target selectivity, and diffusion/excretion kinetics of small molecules in structurally complicated specimens are critical for function. However, robust methods for precisely evaluating these parameters in the brain have been limited. Herein, we report a new method termed “fixation-driven chemical cross-linking of exogenous ligands (FixEL),” which traps and images exogenously administered molecules of interest (MOIs) in complex tissues. This method relies on protein-MOI interactions and chemical cross-linking of amine-tethered MOI with paraformaldehyde used for perfusion fixation. FixEL is used to obtain images of the distribution of the small molecules, which addresses selective/nonselective binding to proteins, time-dependent localization changes, and diffusion/retention kinetics of MOIs such as the scaffold of PET tracer derivatives or drug-like small molecules.

    DOI: 10.1016/j.chempr.2022.11.005

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  6. Discovery of 2,6-Dihalopurines as Stomata Opening Inhibitors: Implication of an LRX-Mediated H plus -ATPase Phosphorylation Pathway

    Ueda, A; Aihara, Y; Sato, S; Kano, K; Mishiro-Sato, E; Kitano, H; Sato, A; Fujimoto, KJ; Yanai, T; Amaike, K; Kinoshita, T; Itami, K

    ACS CHEMICAL BIOLOGY   18 巻 ( 2 ) 頁: 347 - 355   2023年1月

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    記述言語:英語   出版者・発行元:ACS Chemical Biology  

    Stomata are pores in the leaf epidermis of plants and their opening and closing regulate gas exchange and water transpiration. Stomatal movements play key roles in both plant growth and stress responses. In recent years, small molecules regulating stomatal movements have been used as a powerful tool in mechanistic studies, as well as key players for agricultural applications. Therefore, the development of new molecules regulating stomatal movement and the elucidation of their mechanisms have attracted much attention. We herein describe the discovery of 2,6-dihalopurines, AUs, as a new stomatal opening inhibitor, and their mechanistic study. Based on biological assays, AUs may involve in the pathway related with plasma membrane H+-ATPase phosphorylation. In addition, we identified leucine-rich repeat extensin proteins (LRXs), LRX3, LRX4 and LRX5 as well as RALF, as target protein candidates of AUs by affinity based pull down assay and molecular dynamics simulation. The mechanism of stomatal movement related with the LRXs-RALF is an unexplored pathway, and therefore further studies may lead to the discovery of new signaling pathways and regulatory factors in the stomatal movement.

    DOI: 10.1021/acschembio.2c00771

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  7. Synthesis, properties, and material hybridization of bare aromatic polymers enabled by dendrimer support

    Fujiki, SS; Amaike, K; Yagi, A; Itami, K

    NATURE COMMUNICATIONS   13 巻 ( 1 ) 頁: 5358   2022年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Nature Communications  

    Aromatic polymers are the first-choice platform for current organic materials due to their distinct optical, electronic, and mechanical properties as well as their biocompatibility. However, bare aromatic polymer backbones tend to strongly aggregate, rendering them essentially insoluble in organic solvent. While the typical solution is to install many solubilizing substituents on the backbones, this often provokes undesired property changes. Herein, we report the synthesis of bare aromatic polymers enabled by a dendrimer support. An initiator arene containing a diterpenoid-based dendrimer undergoes Pd-catalyzed polymerization with monomers bearing no solubilizing substituents to furnish bare aromatic polymers such as polythiophenes and poly(para-phenylene)s. The high solubility of dendrimer-ligated polymers allows not only the unveiling of the properties of unsubstituted π-conjugated backbone, but also mild release of dendrimer-free aromatic polymers and even transfer of aromatic polymers to other materials, such as silica gel and protein, which may accelerate the creation of hybrid materials nowadays challenging to access.

    DOI: 10.1038/s41467-022-33100-7

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    その他リンク: https://www.nature.com/articles/s41467-022-33100-7

  8. Photopharmacological Manipulation of Mammalian CRY1 for Regulation of the Circadian Clock

    Kolarski, D; Miller, S; Oshima, T; Nagai, Y; Aoki, Y; Kobauri, P; Srivastava, A; Sugiyama, A; Amaike, K; Sato, A; Tama, F; Szymanski, W; Feringa, B; Itami, K; Hirota, T

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   143 巻 ( 4 ) 頁: 2078 - 2087   2021年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of the American Chemical Society  

    CRY1 and CRY2 proteins are highly conserved components of the circadian clock that controls daily physiological rhythms. Disruption of CRY functions are related to many diseases, including circadian sleep phase disorder. Development of isoform-selective and spatiotemporally controllable tools will facilitate the understanding of shared and distinct functions of CRY1 and CRY2. Here, we developed CRY1-selective compounds that enable light-dependent manipulation of the circadian clock. From phenotypic chemical screening in human cells, we identified benzophenone derivatives that lengthened the circadian period. These compounds selectively interacted with the CRY1 photolyase homology region, resulting in activation of CRY1 but not CRY2. The benzophenone moiety rearranged a CRY1 region called the "lid loop"located outside of the compound-binding pocket and formed a unique interaction with Phe409 in the lid loop. Manipulation of this key interaction was achieved by rationally designed replacement of the benzophenone with a switchable azobenzene moiety whose cis-trans isomerization can be controlled by light. The metastable cis form exhibited sufficiently high half-life in aqueous solutions and structurally mimicked the benzophenone unit, enabling reversible period regulation over days by cellular irradiation with visible light. This study revealed an unprecedented role of the lid loop in CRY-compound interaction and paves the way for spatiotemporal regulation of CRY1 activity by photopharmacology for molecular understanding of CRY1-dependent functions in health and disease.

    DOI: 10.1021/jacs.0c12280

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  9. An Isoform-Selective Modulator of Cryptochrome 1 Regulates Circadian Rhythms in Mammals 国際誌

    Miller, S; Aikawa, Y; Sugiyama, A; Nagai, Y; Hara, A; Oshima, T; Amaike, K; Kay, SA; Itami, K; Hirota, T

    CELL CHEMICAL BIOLOGY   27 巻 ( 9 ) 頁: 1192 - +   2020年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Cell Chemical Biology  

    Cryptochrome 1 (CRY1) and CRY2 are core regulators of the circadian clock, and the development of isoform-selective modulators is important for the elucidation of their redundant and distinct functions. Here, we report the identification and functional characterization of a small-molecule modulator of the mammalian circadian clock that selectively controls CRY1. Cell-based circadian chemical screening identified a thienopyrimidine derivative KL201 that lengthened the period of circadian rhythms in cells and tissues. Functional assays revealed stabilization of CRY1 but not CRY2 by KL201. A structure-activity relationship study of KL201 derivatives in combination with X-ray crystallography of the CRY1-KL201 complex uncovered critical sites and interactions required for CRY1 regulation. KL201 bound to CRY1 in overlap with FBXL3, a subunit of ubiquitin ligase complex, and the effect of KL201 was blunted by knockdown of FBXL3. KL201 will facilitate isoform-selective regulation of CRY1 to accelerate chronobiology research and therapeutics against clock-related diseases.

    DOI: 10.1016/j.chembiol.2020.05.008

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  10. Small Molecules Modulating Mammalian Biological Clocks: Exciting New Opportunities for Synthetic Chemistry

    Amaike, K; Oshima, T; Skoulding, NS; Toyama, Y; Hirota, T; Itami, K

    CHEM   6 巻 ( 9 ) 頁: 2186 - 2198   2020年9月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Chem  

    Challenges and opportunities: • Increasing opportunities for the discovery of new circadian clock modulators, which are attractive drug candidates for clock-related diseases in pharmaceutical industry, and to enhance crop yield in agriculture. • Development of new reactions for rapid access to hit compound derivatives, accelerating structure-activity relationship studies, which are generally time consuming. • New approaches for target identification of clock-modulating small molecules, which is still challenging, enable molecular-level understanding and new structural designs.

    DOI: 10.1016/j.chempr.2020.08.011

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  11. Construction of a Fluorescent Screening System of Allosteric Modulators for the GABA<sub>A</sub> Receptor Using a Turn-On Probe 査読有り

    Sakamoto, S; Yamaura, K; Numata, T; Harada, F; Amaike, K; Inoue, R; Kiyonaka, S; Hamachi, I

    ACS CENTRAL SCIENCE   5 巻 ( 9 ) 頁: 1541 - 1553   2019年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ACS Central Science  

    γ-Aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the central nervous system. The fast inhibitory actions of GABA are mainly mediated by GABAA receptors (GABAARs), which are widely recognized as clinically relevant drug targets. However, it remains difficult to create screening systems for drug candidates that act on GABAARs because of the existence of multiple ligand-binding sites and the delicate pentameric structures of GABAARs. We here developed the first turn-on fluorescent imaging probe for GABAARs, which can be used to quantitatively evaluate ligand-receptor interactions under live cell conditions. Using noncovalent labeling of GABAARs with this turn-on probe, a new imaging-based ligand assay system, which allows discovery of positive allosteric modulators (PAMs) for the GABAAR, was successfully constructed. Our system is applicable to high-throughput ligand screening, and we discovered new small molecules that function as PAMs for GABAARs. These results highlight the power of the use of a turn-on fluorescent probe to screen drugs for complicated membrane proteins that cannot be addressed by conventional methods.

    DOI: 10.1021/acscentsci.9b00539

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  12. Synthesis of multiply arylated pyridines 査読有り

    Asako, T; Hayashi, W; Amaike, K; Suzuki, S; Itami, K; Muto, K; Yamaguchi, J

    TETRAHEDRON   73 巻 ( 26 ) 頁: 3669 - 3676   2017年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Tetrahedron  

    We have achieved a synthesis of multiply arylated pyridines by using a [4 + 2] cycloaddition of 2,4-diaryl-5-chloroxazoles and cinnamic acids as a key reaction. The resulting hydroxytriarylpyridines can be derivatized into triarylpyridines, tetraarylpyridines and pentaarylpyridines by sequential cross-couplings. This synthetic method allows for facile and rapid access to highly arylated pyridines with different aryl substituents.

    DOI: 10.1016/j.tet.2017.03.095

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  13. Affinity-Guided Oxime Chemistry for Selective Protein Acylation in Live Tissue Systems. 査読有り

    Tamura T, Song Z, Amaike K, Lee S, Yin S, Kiyonaka S, Hamachi I

    Journal of the American Chemical Society   139 巻 ( 40 ) 頁: 14181 - 14191   2017年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1021/JACS.7B07339

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  14. Recognition-driven chemical labeling of endogenous proteins in multi-molecular crowding in live cells. 査読有り

    Amaike K, Tamura T, Hamachi I

    Chemical communications (Cambridge, England)   53 巻 ( 88 ) 頁: 11972 - 11983   2017年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1039/C7CC07177A

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  15. Synthesis of Triarylpyridines in Thiopeptide Antibiotics by Using a C-H Arylation/Ring-Transformation Strategy 査読有り

    Amaike, K; Itami, K; Yamaguchi, J

    CHEMISTRY-A EUROPEAN JOURNAL   22 巻 ( 13 ) 頁: 4384 - 4388   2016年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Chemistry - A European Journal  

    We have described a C-H arylation/ring-transformation strategy for the synthesis of triarylpyridines, which form the core structure of thiopeptide antibiotics. This synthetic method readily gave 2,3,6-triarylpyridines in a regioselective manner by a two-phase approach: C-H arylation (a nickel-catalyzed decarbonylative Suzuki-Miyaura cross-coupling and decarbonylative C-H coupling for the synthesis of 2,4-diaryloxazoles) and ring transformation ([4+2] cycloaddition of 2,4-diaryloxazoles with (hetero)arylacrylic acids). To showcase these methods, we have accomplished the formal synthesis of thiopeptide antibiotics GE2270 s and amythiamicins.

    DOI: 10.1002/chem.201600351

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  16. Direct C7 Functionalization of Tryptophan. Synthesis of Methyl (<i>S</i>)-2-((<i>tert</i>-Butoxycarbonyl)amino)-3-(7-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1<i>H</i>-indol-3-yl)propanoate. 査読有り

    Amaike K, Loach RP, Movassaghi M

    Organic syntheses; an annual publication of satisfactory methods for the preparation of organic chemicals   92 巻   頁: 373 - +   2015年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.15227/ORGSYN.092.0373

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  17. β-Selective C-H Arylation of Pyrroles Leading to Concise Syntheses of Lamellarins C and I 査読有り

    Ueda, K; Amaike, K; Maceiczyk, RM; Itami, K; Yamaguchi, J

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   136 巻 ( 38 ) 頁: 13226 - 13232   2014年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of the American Chemical Society  

    The first general β-selective C-H arylation of pyrroles has been developed by using a rhodium catalyst. This C-H arylation reaction, which is retrosynthetically straightforward but results in unusual regioselectivity, could result in de novo syntheses of pyrrole-derived natural products and pharmaceuticals. As such, we have successfully synthesized polycyclic marine pyrrole alkaloids, lamellarins C and I, by using this β-selective arylation of pyrroles with aryl iodides (C-H/C-I coupling) and a new double C-H/C-H coupling as key steps.

    DOI: 10.1021/ja508449y

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  18. Late-Stage C-H Coupling Enables Rapid Identification of HDAC Inhibitors: Synthesis and Evaluation of NCH-31 Analogues 査読有り

    Sekizawa, H; Amaike, K; Itoh, Y; Suzuki, T; Itami, K; Yamaguchi, J

    ACS MEDICINAL CHEMISTRY LETTERS   5 巻 ( 5 ) 頁: 582 - 586   2014年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ACS Medicinal Chemistry Letters  

    We previously reported the discovery of NCH-31, a potent histone deacetylase (HDAC) inhibitor. By utilizing our C-H coupling reaction, we rapidly synthesized 16 analogues (IYS-1 through IYS-15 and IYS-Me) of NCH-31 with different aryl groups at the C4-position of 2-aminothiazole core of NCH-31. Subsequent biological testing of these derivatives revealed that 3-fluorophenyl (IYS-10) and 4-fluorophenyl (IYS-15) derivatives act as potent pan-HDAC inhibitor. Additionally, 4-methylphenyl (IYS-1) and 3-fluoro-4-methylphenyl (IYS-14) derivatives acted as HDAC6-insensitive inhibitors. The present work clearly shows the power of the late-stage C-H coupling approach to rapidly identify novel and highly active/selective biofunctional molecules. © 2014 American Chemical Society.

    DOI: 10.1021/ml500024s

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  19. C7-derivatization of C3-alkylindoles including tryptophans and tryptamines. 査読有り

    Loach RP, Fenton OS, Amaike K, Siegel DS, Ozkal E, Movassaghi M

    The Journal of organic chemistry   79 巻 ( 22 ) 頁: 11254 - 11263   2014年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1021/JO502062Z

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  20. Nickel-Catalyzed Direct Coupling of Heteroarenes

    Yamaguchi Junichiro, Muto Kei, Amaike Kazuma, Yamamoto Takuya, Itami Kenichiro

    JOURNAL OF SYNTHETIC ORGANIC CHEMISTRY JAPAN   71 巻 ( 6 ) 頁: 576 - 587   2013年6月

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    記述言語:日本語  

    Web of Science

  21. Nickel-catalyzed direct coupling of heteroarenes 査読有り

    Yamaguchi J., Muto K., Amaike K., Yamamoto T., Itami K.

    Yuki Gosei Kagaku Kyokaishi/Journal of Synthetic Organic Chemistry   71 巻 ( 6 ) 頁: 576 - 587   2013年

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Yuki Gosei Kagaku Kyokaishi/Journal of Synthetic Organic Chemistry  

    Nickel-catalyzed cross-coupling reactions have recently been receiving significant attention from the synthetic community as a way to construct carbon-carbon or carbon-heteroatom bonds, because nickel catalysts are less expensive and less toxic than palladium catalysts. We herein describe our recent developments in nickel-catalyzed biaryl coupling methodology, along with mechanistic studies and applications to the synthesis of natural products and pharmaceuticals. In particular, we focus on nickel-catalyzed direct coupling reactions in which "unreactive" bonds such as C-H, C-O, and C-C bonds are converted into biaryl moieties.

    DOI: 10.5059/YUKIGOSEIKYOKAISHI.71.576

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  22. Decarbonylative C-H Coupling of Azoles and Aryl Esters: Unprecedented Nickel Catalysis and Application to the Synthesis of Muscoride A 査読有り

    Amaike, K; Muto, K; Yamaguchi, J; Itami, K

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   134 巻 ( 33 ) 頁: 13573 - 13576   2012年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of the American Chemical Society  

    A nickel-catalyzed decarbonylative C-H biaryl coupling of azoles and aryl esters is described. The newly developed catalytic system does not require the use of expensive metal catalysts or silver- or copper-based stoichiometric oxidants. We have successfully applied this new C-H arylation reaction to a convergent formal synthesis of muscoride A. © 2012 American Chemical Society.

    DOI: 10.1021/ja306062c

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▼全件表示

MISC 1

  1. Synthesis of Natural Products and Pharmaceuticals via Catalytic C-H Functionalization

    Yamaguchi J., Amaike K., Itami K.  

    Transition Metal-Catalyzed Heterocycle Synthesis via C-H Activation   頁: 505 - 550   2016年1月

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    記述言語:英語   出版者・発行元:Transition Metal-Catalyzed Heterocycle Synthesis via C-H Activation  

    The synthesis of natural products and pharmaceuticals, particularly those containing heterocyclic frameworks, can be dramatically simplified by using catalytic C-H functionalization. C-H functionalization has gathered significant interest from the organic synthesis community because it provides a new strategy to construct carbon-carbon and carbon-heteroatom bonds in highly functionalized, complex molecules without prefunctionalization. In this book chapter, methods in heterocycle substitution and synthesis using catalytic C-H functionalization are classified by heterocycle, with specific focus on the cutting-edge synthesis of natural products and pharmaceuticals.

    DOI: 10.1002/9783527691920.ch16

    Scopus

科研費 3

  1. 核酸輸送を加速させる一次元伸張ナノカーボン分子の創製

    研究課題/研究課題番号:22K14797  2022年4月 - 2024年3月

    日本学術振興会  科学研究費助成事業  若手研究

    天池 一真

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    担当区分:研究代表者 

    配分額:4680000円 ( 直接経費:3600000円 、 間接経費:1080000円 )

    核酸輸送はDNAやRNAを外部から宿主細胞に導入することであり、創薬や育種の現場から基礎生物学に至るまで生命科学研究に絶対的に不可欠な技術である。生命現象の理解と制御のさらなる高度化が必要な今、効率や選択性はもちろんのこと生体直交性などの多様な機能が核酸輸送に求められている。核酸輸送の分野に全く新しい方法、キャリア分子群の登場がまたれる所以である。本研究では、哺乳・植物・昆虫を対象とした核酸輸送を加速させるテーラーメイドな核酸輸送ナノカーボン分子を創製することで基礎と応用の両面からこの分野に非線形のブレークスルーをもたらす。
    近年、核酸医薬やゲノム編集技術といった核酸を用いた技術の発展が目覚ましい。これらの技術は基本的に、核酸が核に到達することで機能が発揮されるため、効率的に外部から核酸を輸送することが求められる。しかし生物は細胞膜や細胞壁などの脂溶性の高い物理的な障壁を持つため、電荷を帯びた核酸を細胞内に輸送するのは一般的に困難である。そのため現在においても核酸輸送法の開発、改良が進められている。近年、カチオン性カーボンナノチューブをはじめとする炭素材料(ナノカーボン)が、新たな核酸輸送のための次世代キャリアとして期待が高まっている。しかしその詳細な作用機序、最適なナノカーボンの構造情報は不明のままである。そのため本研究課題では、精密に構造が制御されたナノカーボン分子を合成し、哺乳、植物、昆虫を対象とした構造物性相関研究をおこない、それぞれの生物種に合わせたテーラーメイドなナノカーボン分子の創製をおこなう。分子設計に関しては、細胞外におけるナノカーボン分子と核酸との相互作用、細胞膜、細胞壁の透過能、そして細胞内における核酸の解離を念頭においておこなう。一次元に伸張したナノカーボン分子の合成に関しては共有結合的に伸張させる方法を確立した。すなわち、最近報告したデンドリマーを担体とした芳香族ポリマー(Fujiki et al. Nature Communications 2022, 13, 5358.)に対して、ポリエチレンイミンを作用させることで、一段階で種々の一次元に伸張したナノカーボン分子を合成した。
    近年、カチオン性カーボンナノチューブをはじめとする炭素材料(ナノカーボン)が、新たな核酸輸送のための次世代キャリアとして期待が高まっているものの、その詳細な作用機序、最適なナノカーボンの構造情報は不明のままである。今回、一次元に伸張したナノカーボン分子の合成に関しては共有結合的に伸張させる方法を確立した。すなわち、最近報告したデンドリマーを担体とした芳香族ポリマー(Fujiki et al. Nature Communications 2022, 13, 5358.)に対して、ポリエチレンイミンを作用させることで、一段階で種々の一次元に伸張したカチオン性ナノカーボン分子を合成した。
    複数種類の一次元伸長ナノカーボンを精密に合成できたため、おおむね順調に研究は進行している。
    今年度合成を達成した分子を用いて構造物性相関研究を遂行する。またその結果をもとに、一次元伸長ナノカーボンの骨格デザインや、付与するカチオン性ポリマーを変更し、哺乳類、昆虫、植物それぞれに最適な核酸輸送材料を合成する。

  2. シナジー効果を有する化合物群のAI による探索と設計

    研究課題/研究課題番号:20H05797  2020年10月 - 2023年3月

    日本学術振興会  科学研究費助成事業  学術変革領域研究(B)

    山西 芳裕, 天池 一真, 竹下 潤一, 味八木 茂

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    担当区分:研究分担者 

    複数の薬剤の組み合わせによる相乗効果(薬剤シナジー)を活用した化学療法が、がんや神経変性疾患など多因子疾患に対する有効な治療法として注目されている。本研究では、疾患状態の生体情報を入力とし、シナジー効果を有する薬剤群を予測するAIを開発する。さらに、より高いシナジー効果を有する新しい化合物群を設計するAIを開発する。有機化合物の組み合わせ数は膨大であり、実験的に全ての可能性を検証することは不可能である。生体情報から複数の薬剤群(または化合物群)を最適化できないか?という問いに対し、物質・生命科学のビッグデータと情報科学のAI技術を融合し、新たな方法論を創生する。
    複数の薬剤の組合せによる相乗効果(薬剤シナジー)を活用した化学療法が、がんや神経変性疾患など多因子疾患に対する有効な治療法として注目されている。本計画研究班は、シナジー効果を有する薬剤群を予測する統計手法を開発する。具体的には、以下の3段階で研究を進める。1)疾患特異的オミックスデータ、薬剤応答オミックスデータ、分子間相互作用ネットワークを融合解析し、シナジー効果を有する薬剤群を予測する手法を開発。2)生体分子のネットワーク解析を行い、薬剤シナジーの作用機序を考察。3)より高いシナジー効果を有する新しい化合物の化学構造を発生・設計する手法を開発。
    これまで臨床研究での偶発的発見や限られた薬剤ペアに対する実験的検証に留まっていた薬剤シナジーに対し、本研究では、薬剤全ての組合せをAIで探索することで、これまでのボトルネックであった組合せ爆発の問題の解決に寄与する。本研究の特色は、疾患特異的な発現異常遺伝子群と薬剤に応答する発現異常遺伝子群を考慮して薬剤シナジーを解析する点にある。薬剤シナジーは、生命システムの動的反応の結果であるため、オミックスデータの活用によって、薬剤シナジーの正確な理解や予測につながることが期待できる。

  3. フェアリー化合物の科学とその応用展開

    研究課題/研究課題番号:20H05620  2020年7月 - 2025年3月

    日本学術振興会  科学研究費助成事業  特別推進研究

    河岸 洋和, 天池 一真, 鈴木 智大, 室井 誠, 高橋 公咲, 謝 肖男, 野村 崇人, 大内 仁志, 一家 崇志, 菅 敏幸, 伊藤 英人

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    担当区分:研究分担者 

    芝が輪状に周囲より繁茂あるいは枯死した後にキノコが発生する現象を「フェアリーリング」という。研究代表者はこの現象の原因物質(AHX,ICA,AOH)を発見した。その後,これら3物質(フェアリー化合物,fairy chemicalsと総称,FCsと略称)の植物における内生が判明し,さらに圃場試験において農作物の増収効果を示した。本研究では,植物と菌類中で新規な経路でこれらの物質が生合成されることを明らかにし,活性発現分子機構を解明する。また,農業への実用化を目指しFCsの作物の栽培実験での効果と作用機構を検討する。最終的にはFCsが新しい植物ホルモンであることを証明する。
    研究成果の概要を以下に箇条書きする。
    1. FCsの生合成経路・代謝経路・活性発現機構の解明:FCs骨格起源の候補であるアルギニンを含めた数種の同位体ラベルアミノ酸の取り込み実験を行い,骨格の起源を検討し,アルギニンとグリシンの炭素と窒素がFCsの骨格に取り込まれることを証明した。イネから得られたS-ICAr-Hを,ICAを処理したシロイヌナズナ,出芽酵母でも生成することを明らかにし,論文として発表した。また,試した全てのキノコ類にFCsが普遍的に内生することを明らかにした。
    2. FCsによる作物増産効果の分子機構の解明:各種オオムギに対するFCsの効果を圃場試験で明らかにした。特にAHXが初期生育段階で強力な促進活性を示した。その分子機構を検討中である。
    3. FCsの多彩な研究を支援する合成化学的アプローチ:FCsの生体内誘導体として内生する可能性が考えれれるFCSのメチル化体,アセチル化体などの合成を行った。既存のFCs誘導体の一つであるAHXリボシドを原料として、そのアミド部位のカルボニル酸素原子を、様々なアルキル基を有する窒素原子へと直接変換する手法を確立した。ICAに対するC2位への触媒的C-Hアリール化法を確立した。
    4. 新たな展開:ICAが癌細胞における免疫チェックポイント分子PD-L1とPD-L2の形成を抑制し,抗癌剤シスプラチンの効果を高めることを動物実験で明らかにした。AOHがヒトの肌に対して,保湿効果やターンオーバーの促進,障害回復効果を示すこととその安全性を,試験官レベル,動物実験,臨床試験で明らかにし,その活性発現機構を遺伝子レベルで解析した。
    研究成果概要で述べたように,1)FCsの生合成経路・代謝経路・活性発現機構の解明,2)FCsによる作物増産効果の解明,3)FCsの多彩な研究を支援する合成化学的アプローチ,4)新たな展開,の全ての項目で,計画通りあるいは計画以上に進んでいる。原著論文4報,総説1報,著書1冊を著し,国内外で8件の招待講演を行った。
    今後の研究の推進方策を以下に箇条書きする。
    1) コムラサキシメジでのAHXの1,2,3-triazine骨格の形成メカニズムを明らかにする。2) 果実の成熟・老化におけるFCs化合物の内生量について検討する。FCsの根寄生植物種子発芽の影響について検討する。3)S-ICAr-H 以外のSAM類縁体の化学合成方法を検討する。4)表面プラズモン共鳴法により,AHXとAHX結合候補タンパク質であるイネのATPaseサブユニットBの結合を検討する。5)AHX類縁体の2-アザアデノシンが植物に内生している可能性を検討し,その可能性があれば,位置選択的にアルキル化された2-アザアデノシン類の合成方法の開発を目指す。6)ICAに対するC2位への触媒的C-Hアリール化反応を用いてICA誘導体のライブラリーを構築し,その生物活性をICAや他の FCsと比較する。7) イネコアコレクション102系統の地上部ならびに地下部の長さに対するAOH応答性を評価し,イネの生育調節におけるAOH作用機序の遺伝的多様性を検討する。 AOH応答の相対根長に基づいたGWASを行う。8)AOHのヒトの肌に対するさらなる効果を明らかにし,応用面では,AOHが化粧品原料として上市を目指す。