Haruki NIWA

Title: Professor

Email: niwa@ PC (Please replace PC with pc.uec.ac.jp)

Phone: +81-42-443-5484

Office: East-6 Bldg. 836

Personal Information

1994/04- Professor of Faculty of Electro-communications, The University of Electro-communications
1984/03-1994/03 Associate Professor of Faculty of Science, Nagoya University
1980/06-1984/03 Assistant Professor of Faculty of Science, Nagoya University
1973/04-1980/06 Research Chemist of Central Reasearch Lab., Ono Pharmaceutical Co. Ltd.
Ph.D. 1979, Nagoya University
M.S. 1973, Nagoya University
B.S. 1971, Nagoya University

Research Fields

Bioorganic Chemistry

Summary of Research Activities

There may be nobody who is not fascinated and excited with a marvelous light created by fireflies dancing over streams and fields in early summer evnings. It is so amazing that since ancient times, many luminous organisms produce cold light, so-called bioluminescence by oxidation of organic compounds in their bodies. Another amazing event in bioluminescence is that the efficiency of conversion of the chemical energy into light is so high; for example, the quantum yield of the firefly bioluminescence Phi_BL is 0.88! The quantum yield Phi_BL is the product of Phi_CR (the efficiency of chemical reaction) x Phi_S1 (the efficiency of production of S1 excited sate) x Phi_Fl (the quantum yield of fluorescence from the light emmiter). Thus, "Phi_BL = 0.88" means that the each efficency of Phi_CR, Phi_S1, and Phi_Fl is more than 0.96! So far, we can't realize such high efficient energy conversion by any light-producing devise such as electric light or by chemiluminescence.

We currently study how luminous organisms, in particular, the luminous mushroom Mycena cyanophos (YAKOU-TAKE in Japanese), the sea fireworm Odontosyllis undecimdonta, luminous sea hare (BEKKOU-HIKALI-UMIUSHI in Japanese) make such fascinating light, how the organisms convert the chemical energy to light so efficiently, and how the nature controls the bioluminescence color. We now try to isolate luciferins (light producing organic compounds) from these organisms. We will determine the molecular structure by using NMR, MS, IR, and UV spectrometries etc. When the chemical structures of the luciferins were determined, we will synthesize the luciferins and confirm the proposed structures. Then we study the molecular mechanism of light production reaction using synthesized luciferins. In near future, we will be able to construct man-made bioluminescence systems having the similar efficiency and different colors, by utilizing the knowledge accumulated by the research of these and other bioluminescence systems.

In addition we would like to develop efficient and unique bioimaging and biosensing systems helpful for human welfare. Based on the structures of the luciferins, we will also develop newly designed light-emitting substances for photonics materials.