Bulletin of Keio University Faculty of Science and Technology
  kyurizukai interview  
09 Kiyotake Suenaga 2 Starting a researcher’s life

photoWhat was the first research work in your life like?
      My first research theme was chemical synthesis of Aplyronine A. This substance can be obtained from sea hares, a marine organism that looks like a large slug. Aplyronine A is an anticancer substance discovered by the Yamada lab. It interacts with actin, the knowledge of which was quite innovative in those days. I came within an inch of success by the end of the second year of the master’s course. But the last reaction would not take place, which put me at the end of my rope after all. Reluctantly, I had to go far back to a substance of the early stage and rebuild the synthesis method. I was like a climber who reached the ninth stage of a mountain but was suddenly pulled back down to the third stage. Even so, I remained steadfast, thinking I should not abandon the project halfway. It was at the end of the first year in the doctor’s course that I finally succeeded in the synthesis.
      Incidentally, Dr. Hideo Kigoshi (University of Tsukuba), a disciple of Dr. Yamada, has taken over the research into the substance’s action mechanism. At a recent academic meeting I had an opportunity to listen to Dr. Kigoshi’s lecture that mentioned a new development in the study of the action mechanism.
      Completion of the Aplyronine A synthesis urged me to ask Dr. Yamada for permission to isolate it and determine its structure myself. It had been my wish to do the task if I had advanced to the doctor’s course. I wanted to find a new substance on my own instead of synthesizing something that has been isolated and structure-determined by someone else. Dr. Yamada told me right away, “Isolate it yourself.” I felt that my teacher must have known my wish before I put it into words.
      In those days, there was a substance from the sea hare Dollabella auricularia that was too hard to capture. Though the substance had a very strong activity, the amount available was extremely small. Using an extract equivalent to 250 kilograms of the sea hare, I patiently repeated the isolation process over and over again and finally obtained about 0.5mg of substance called Aurilide. It was one of the smallest amounts among the substances I had ever obtained. I used that sample to conduct two kinds of experiments for structure determination and consumed all of the natural Aurilide. The experiments strained my nerves. Once its molecular structure was identified, it was possible to synthesize the substance. I synthesized about 1.5 grams of it and conducted experiments on animals to verify its anticancer properties. But this substance could not be developed into a pharmaceutical because of toxicity.

You’ve had a number of significant experiences since your student days, haven’t you?
      Actually, I was already a research associate by that time. I quit the doctor’s course in February of the first year to fill the research associate’s post because the former research associate transferred to another lab as an associate professor. Whether willing or not and given little time to think about my future, I found myself hastily starting a researcher’s career.


<< PREV TOP 1 2 3 NEXT >>


1 An encounter with a great teacher
2 Starting a researcher’s life
3 Putting much importance on time for communicating with family  and students
Profile Kiyotake Suenaga Dr. Suenaga’s specialty is marine natural product chemistry. He is engaged in exploration of biologically active substances. Currently, his focus is on marine cyanobacteria. In 1992, he was enrolled in Nagoya University’s Graduate School of Science. In 1995, he left the doctor’s course to become a research assistant for the Department of Chemistry, Faculty of Science of the university. In 1997, he acquired a doctor’s degree (in science). After serving as a research assistant for Shizuoka Prefectural University (Pharmaceutical Department) then as an assistant professor for the University of Tsukuba (Department of Chemistry), in 2006 he assumed the current position as an associate professor for Department of Chemistry, Keio University Faculty of Science and Technology. Dr. Suenaga was honored with the Inoue Research Award for Young Scientists in 1998 and the Chemical Society of Japan Award for Young Chemists in 2003.

kyurizukai top