Centers & Labs

Associate Chief Scientist Laboratories

Biofunctional Synthetic Chemistry Laboratory

Associate Chief Scientist: Katsunori Tanaka (Ph.D.)
Katsunori  Tanaka(Ph.D.)

Although many efficient bond-forming reactions have been developed in the field of synthetic organic chemistry, their utility typically fails to translate in complex mixtures present in cellular or living biosystems. As such, only a handful of effective labeling or conjugation methods in biosystems are readily available. To address this issue, we are synthetically exploring the unique reactivity of conjugated imines for their potential in novel chemical reactions. The benefit of this approach is that since a large part of amine-containing biomacromolecules are biosynthesized through imine chemistry, imine-mediated chemical reactions will not face the same challenges that classical synthetic organic chemical reactions face within living systems. In parallel to this work, our studies have also shown that the unique reactivity of imines could be involved in pathways that regulate biologically important processes.

Besides usage in methods of labeling or conjugation, the novel reactivity of imines could alternatively be used in the multi-step synthesis of biofunctional molecules within living biosystems. Through a concept we refer to as “Therapeutic In Vivo Synthetic Chemistry”, we aim to develop an adaptable system where a cascade of organic transformations can be directly executed at target regions within the body during predefined times to generate a bioactive molecule that elicits a localized biological effect. Towards this goal, we are analyzing, with the use of molecular imaging, the complex “pattern recognition” mechanisms of natural glycans in vivo and applying the glycan-based interactions to direct various linked biomolecules to desired organs and tissues.

Main Research Field

Chemistry

Related Research Fields

Biology & Biochemistry / Molecular Biology & Genetics / Clinical Medicine

Research Subjects

  • Exploring the Overlooked Reactivity of Conjugated Imines: Functional Studies of Novel Modification of Biomolecules
  • Therapeutic In Vivo Synthetic Chemistry: Multi-step Synthesis in Live Animals
  • Molecular Imaging of Glycan Pattern Recognition: Application to Molecular Targeting

Selected Publications

  1. T. Iwata, S. Otsuka, K. Tsubokura, A. Kurbangalieva, D. Arai, K. Fukase, Y. Nakao and K. Tanaka:
    "One-pot evolution of ageladine A via bio-inspired cascade towards selective modulators of neuronal differentiation"
    Chem. Eur. J., in press, (2016).
  2. A. Tsutsui, T. Zako, T. Bu, Y. Yamaguchi, M. Maeda and K. Tanaka:
    "1,5-Diazacyclooctanes, as Exclusive Oxidative Polyamine Metabolites, Inhibit Amyloid-β(1-40) Fibrillization"
    Adv. Sci., 1600082 (2016).
  3. A. R. Pradipta, M. Taichi, I. Nakase, E. Saigitbatalova, A. Kurbangalieva, S. Kitazume, N. Taniguchi and K. Tanaka:
    "Uncatalyzed Click Reaction between Phenyl Azides and Acrolein: 4-Formyl-1,2,3-Triazolines as “Clicked” Markers for Visualizations of Extracellular Acrolein Released from Oxidatively Stressed Cells"
    ACS Sens., 1, 623-632 (2016).
  4. A. Ogura, T. Tahara, S. Nozaki, K. Morimoto, Y. Kizuka, S. Kitazume, M. Hara, S. Kojima, H. Onoe, A. Kurbangalieva, N. Taniguchi, Y. Watanabe and K. Tanaka:
    "Visualizing Trimming Dependence of Biodistribution and Kinetics with Homo- and Heterogeneous N-Glycoclusters on Fluorescent Albumin"
    Sci. Rep., 6, 21797 (2016).
  5. K. Fukase and K. Tanaka:
    "Bio-Imaging and Cancer Targeting with Glycoproteins and N-Glycans"
    Curr. Opin. Chem. Biol., 16, 614-621 (2012).
  6. K. Tanaka, S. Shirotsuki, C. Kageyama, T. Tahara, S. Nozaki, E. R. O. Siwu, T. Iwata, S. Tamura, S. Douke, N. Murakami, H. Onoe, Y. Watanabe and K. Fukase:
    "Template-Assisted and Self-Activating Clicked Peptide as a Synthetic Mimic of the SH2 Domain"
    ACS Chem. Biol., 7, 637-645 (2012).
  7. K.Tanaka, K. Fukase and S. Katsumura:
    "Exploring A Unique Reactivity of 6π-Azaelectrocyclization to Enzyme Inhibition, Natural Products Synthesis, and Molecular Imaging: An Approach to Chemical Biology by Synthetic Chemists"
    Synlett, 2115-2139 (2011).
  8. K. Tanaka, E. R. O. Siwu, K. Minami, K. Hasegawa, S. Nozaki, Y. Kanayama, K. Koyama, C. W. Chen, J. C. Paulson, Y. Watanabe and K. Fukase:
    "Noninvasive Imaging of Dendrimer-type N-Glycan Clusters: In Vivo Dinamics Dependence on Oligosaccharides Structure"
    Angew. Chem. Int. Ed., 49, 8195-8200 (2010).
  9. K. Tanaka, K. Minami, T. Tahara, Y. Fujii, E. R. O. Siwu, S. Nozaki, H. Onoe, S. Yokoi, K. Koyama, Y. Watanabe and K. Fukase:
    "Electrocyclization-Based Labeling Allows Efficient In Vivo Imaging of Cellular Trafficking"
    ChemMedChem, 5, 841-845 (2010).
  10. K. Tanaka, T. Masuyama, K. Hasegawa, T. Tahara, H. Mizuma, Y. Wada, Y. Watanabe and K. Fukase:
    "A Submicrogram-Scale Protocol for Biomolecule-based PET Imaging via Rapid 6π -Azaelectrocyclization: First Visualization of Sialic Acid-dependent Circulatory Residence of Glycoproteins"
    Angew. Chem. Int. Ed., 47, 102-105 (2008).

Lab Members

Principal Investigator

Katsunori Tanaka
Associate Chief Scientist

Core Members

Ambara Rachmat Pradipta
Postdoctoral Researcher
Ayumi Tsutsui
Postdoctoral Researcher
Kenward Vong
Postdoctoral Researcher
Katsumasa Fujiki
Postdoctoral Researcher
Shogo Nomura
Postdoctoral Researcher
Sayaka Urano
Technical Staff II
Masayuki Takamatsu
Junior Research Associate
Kazuki Tsubokura
Junior Research Associate
Regina Sibgatullina
International Program Associate
Yixuan Lin
Student Trainee
Liliia Latypova
Visiting Scientist
Masayo Ohara
Assistant