Papers - OGURA Akihiro

Total Synthesis of Clavilactones

Ken-ichi Takao, Kento Mori, Kenya Kasuga, Ryuki Nanamiya, Ayumi Namba, Yuuki Fukushima, Ryuichi Nemoto, Takuma Mogi, Hiroyuki Yasui, Akihiro Ogura, Keisuke Yoshida, Kin-ichi Tadano

JOURNAL OF ORGANIC CHEMISTRY (American Chemical Society ({ACS}))  83 ( 13 ) 7060 - 7075 2018.01

Research paper (scientific journal), Joint Work, Accepted,  ISSN  00223263

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A viable strategy for screening the effects of glycan heterogeneity on target organ adhesion and biodistribution in live mice

Akihiro Ogura, Sayaka Urano, Tsuyoshi Tahara, Satoshi Nozaki, Regina Sibgatullina, Kenward Vong, Takehiro Suzuki, Naoshi Dohmae, Almira Kurbangalieva, Yasuyoshi Watanabe, Katsunori Tanaka

Chemical Communications (Royal Society of Chemistry ({RSC}))  54 ( 63 ) 8693 - 8696 2018

Research paper (scientific journal), Joint Work, Lead author, Accepted,  ISSN  13597345

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Synthesis and evaluation of biological activities of vibsanin A analogs

Wataru Matsuki, So Miyazaki, Keisuke Yoshida, Akihiro Ogura, Yukiko Sasazawa, Ien-ichi Takao, Siro Simizu

BIOORGANIC & MEDICINAL CHEMISTRY LETTERS (PERGAMON-ELSEVIER SCIENCE LTD)  27 ( 19 ) 4536 - 4539 2017.08

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0960-894X

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Vibsanin A is an 11-membered vibsane diterpenoid and is reported to induce myeloid cell differentiation via activation of protein kinase C (PKC) without tumor-promoting activity. Therefore, vibsanin A is thought to be an attractive compound for acute myeloid leukemia (AML) therapy. In this study, we synthesized vibsanin A analogs and compared the activity of these compounds for PKC activation and myeloid cell differentiation. We found that the hydroxymethyl group in vibsanin A is an important substituent to induce differentiation of AML cells. Collectively, our results showed the biochemical features of vibsanin A and provided new insights into the development of new antileukemic drugs. (C) 2017 Elsevier Ltd. All rights reserved.

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Total Synthesis and Structural Revision of ClavilactoneD

Takao, Ken-ichi, Nemoto, Ryuichi, Mori, Kento, Namba, Ayumi, Yoshida, Keisuke, Ogura, Akihiro

CHEMISTRY-A EUROPEAN JOURNAL (WILEY-V C H VERLAG GMBH)  23 ( 16 ) 3828 - 3831 2017.03

Research paper (scientific journal), Joint Work, Last author, Accepted,  ISSN  0947-6539

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A structural revision of clavilactoneD, a potent inhibitor of protein tyrosine kinases, was achieved by total syntheses of two newly proposed structures. The syntheses relied on ring-opening/ring-closing metathesis, which transformed a cyclobutenecarboxylate into a -butenolide. The syntheses confirmed that the correct structure of clavilactoneD has an amino group at C-3 instead of a hydroxy group at C-2 in the originally proposed structure.

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In Vivo Gold Complex Catalysis within Live Mice

Kazuki Tsubokura, Kenward K. H. Vong, Ambara R. Pradipta, Akihiro Ogura, Sayaka Urano, Tsuyoshi Tahara, Satoshi Nozaki, Hirotaka Onoe, Yoichi Nakao, Regina Sibgatullina, Almira Kurbangalieva, Yasuyoshi Watanabe, Katsunori Tanaka

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 56 ( 13 ) 3579 - 3584 2017.03

Research paper (scientific journal), Joint Work, Accepted,  ISSN  1433-7851

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In Vivo Gold Complex Catalysis within Live Mice

Kazuki Tsubokura, Kenward K. H. Vong, Ambara R. Pradipta, Akihiro Ogura, Sayaka Urano, Tsuyoshi Tahara, Satoshi Nozaki, Hirotaka Onoe, Yoichi Nakao, Regina Sibgatullina, Almira Kurbangalieva, Yasuyoshi Watanabe, Katsunori Tanaka

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 56 ( 13 ) 3579 - 3584 2017.03

Research paper (scientific journal), Joint Work, Accepted,  ISSN  1433-7851

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Sequential Double "Clicks" toward Structurally Well-Defined Heterogeneous N-Glycoclusters: The Importance of Cluster Heterogeneity on Pattern Recognition In Vivo

Liliya Latypova, Regina Sibgatullina, Akihiro Ogura, Katsumasa Fujiki, Alsu Khabibrakhmanova, Tsuyoshi Tahara, Satoshi Nozaki, Sayaka Urano, Kazuki Tsubokura, Hirotaka Onoe, Yasuyoshi Watanabe, Almira Kurbangalieva, Katsunori Tanaka

ADVANCED SCIENCE (WILEY)  4 ( 2 ) 1600394 - 1600394 2017.02

Research paper (scientific journal), Joint Work, Accepted,  ISSN  2198-3844

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Glycan multivalency effects toward albumin enable N-glycan-dependent tumor targeting

Ogura, Akihiro, Tahara, Tsuyoshi, Nozaki, Satoshi, Onoe, Hirotaka, Kurbangalieva, Almira, Watanabe, Yasuyoshi, Tanaka, Katsunori

BIOORGANIC & MEDICINAL CHEMISTRY LETTERS (PERGAMON-ELSEVIER SCIENCE LTD)  26 ( 9 ) 2251 - 2254 2016.05

Research paper (scientific journal), Joint Work, Lead author, Accepted,  ISSN  0960-894X

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Multivalent interactions play an essential role in molecular recognition in living systems. These effects were employed to target tumor cells using albumin clusters bearing similar to 10 molecules of asparagine-linked glycans (N-glycans). Noninvasive near-infrared fluorescence imaging clearly revealed A431 tumors implanted in BALB/cA-nu/nu mice after 1 h in an N-glycan structure-dependent manner, thereby demonstrating the efficient use of glycan multivalency effects for tumor targeting in vivo. (C) 2016 Elsevier Ltd. All rights reserved.

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Visualizing Trimming Dependence of Biodistribution and Kinetics with Homo- and Heterogeneous N-Glycoclusters on Fluorescent Albumin

Ogura, Akihiro, Tahara, Tsuyoshi, Nozaki, Satoshi, Morimoto, Koji, Kizuka, Yasuhiko, Kitazume, Shinobu, Hara, Mitsuko, Kojima, Soichi, Onoe, Hirotaka, Kurbangalieva, Almira, Taniguchi, Naoyuki, Watanabe, Yasuyoshi, Tanaka, Katsunori

SCIENTIFIC REPORTS (NATURE PUBLISHING GROUP)  6   273 - 279 2016.02

Research paper (scientific journal), Joint Work, Lead author, Accepted,  ISSN  2045-2322

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A series of N-glycans, each sequentially trimmed from biantennary sialoglycans, were homo-or heterogeneously clustered efficiently on fluorescent albumin using a method that combined strain-promoted alkyne-azide cyclization and 6p-azaelectrocyclization. Noninvasive in vivo kinetics and dissection analysis revealed, for the first time, a glycan-dependent shift from urinary to gall bladder excretion mediated by sequential trimming of non-reducing end sialic acids. N-glycoalbumins that were trimmed further, in particular, GlcNAc-and hybrid biantennary-terminated congeners, were selectively taken up by sinusoidal endothelial and stellate cells in the liver, which are critical for diagnosis and treatment of liver fibrillation. Our glycocluster strategy can not only reveal the previously unexplored extracellular functions of N-glycan trimming, but will be classified as the newly emerging glycoprobes for diagnostic and therapeutic applications.

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In vivo imaging of advanced glycation end products (AGEs) of albumin: first observations of significantly reduced clearance and liver deposition properties in mice

Tsutsui, Ayumi, Ogura, Akihiro, Tahara, Tsuyoshi, Nozaki, Satoshi, Urano, Sayaka, Hara, Mitsuko, Kojima, Soichi, Kurbangalieva, Almira, Onoe, Hirotaka, Watanabe, Yasuyoshi, Taniguchi, Naoyuki, Tanaka, Katsunori

ORGANIC & BIOMOLECULAR CHEMISTRY (ROYAL SOC CHEMISTRY)  14 ( 24 ) 5755 - 5760 2016

Research paper (scientific journal), Joint Work, Lead author, Accepted,  ISSN  1477-0520

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Advanced glycation end products (AGEs) are associated with various diseases, especially during aging and the development of diabetes and uremia. To better understand these biological processes, investigation of the in vivo kinetics of AGEs, i.e., analysis of trafficking and clearance properties, was carried out by molecular imaging. Following the preparation of Cy7.5-labeled AGE-albumin and intravenous injection in BALB/cA-nu/nu mice, noninvasive fluorescence kinetics analysis was performed. In vivo imaging and fluorescence microscopy analysis revealed that non-enzymatic AGEs were smoothly captured by scavenger cells in the liver, i.e., Kupffer and other sinusoidal cells, but were unable to be properly cleared from the body. Overall, these results highlight an important link between AGEs and various disorders associated with them, which may serve as a platform for future research to better understand the processes and mechanisms of these disorders.

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Azaelectrocyclization on cell surface: convenient and general approach to chemical biology research

Ogura, Akihiro, Tanaka, Katsunori

TETRAHEDRON (PERGAMON-ELSEVIER SCIENCE LTD)  71 ( 26-27 ) 4518 - 4521 2015.07

Research paper (scientific journal), Joint Work, Lead author, Accepted,  ISSN  0040-4020

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Convenient and general method for live cell surface labeling was established. Azide-containing fluorescences were initially conjugated with the unsaturated ester aldehyde containing the dibenzocyclooctyne (DIBO), by the strain-promoted click reaction. The resulting probes were then treated with the live cells in one-pot process, efficiently labeling the surface lysines by azaelectrocyclization under the mild conditions. (C) 2015 Elsevier Ltd. All rights reserved.

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Microfluidic Mixing of Polyamine with Acrolein Enables the Detection of the [4+4] Polymerization of Intermediary Unsaturated Imines: The Properties of a Cytotoxic 1,5-Diazacyclooctane Hydrogel

Pradipta, Ambara R., Tsutsui, Ayumi, Ogura, Akihiro, Hanashima, Shinya, Yamaguchi, Yoshiki, Kurbangalieva, Almira, Tanaka, Katsunori

SYNLETT (GEORG THIEME VERLAG KG)  25 ( 17 ) 2442 - 2446 2014.10

Research paper (scientific journal), Joint Work, Accepted,  ISSN  0936-5214

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The [4+4] polymerization of an unsaturated imine, generated from the condensation of a polyamine and excess acrolein, was investigated. The polyamine was added by micropipet to acrolein, immediately yielding a mixture of the immiscible polymeric material. Microfluidic mixing was used to gradually form the soluble diazacyclooctane polymers. The polymerization reaction ultimately gave an insoluble cationic hydrogel that adhered strongly to anionic compounds on cell surfaces, including sialoglycan, and displayed a high cytotoxicity.

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Total Synthesis of (-)-Anisatin

Ogura, Akihiro, Yamada, Kohei, Yokoshima, Satoshi, Fukuyama, Tohru

ORGANIC LETTERS (AMER CHEMICAL SOC)  14 ( 6 ) 1632 - 1635 2012.03

Research paper (scientific journal), Joint Work, Lead author, Accepted,  ISSN  1523-7060

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A novel synthetic route to (-)-anisatin has been developed. Our synthesis features a rhodium-catalyzed 1,4-addition of an arylboronic acid, an intramolecular Diels Alder reaction of an ortho-quinone monoketal, a stereoselective [2,3]-Wittig rearrangement, and construction of the oxabicyclo [3.3.1] skeleton via cleavage of an epoxide by a primary amide.

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