A research group led by Senior Assistant Professor Fukuuchi and Associate Professor Saegusa has revealed using mass spectrometry imaging that the sticky part of natto contains high concentrations of purines.Itabashi Campus

On Tuesday, November 18, 2025, a research group led by Senior Assistant Professor Tomoko Fukuuchi of the Teikyo University School Faculty of Pharmaceutical Sciences and Associate Professor Daisuke Saegusa of the same school, in a joint study with the University of Turin (Italy), analyzed the purines contained in the sticky part of natto and found that high concentrations of adenosine and guanosine were detected.

Until now, it was thought that the purines contained in natto were released in large amounts into the soybeans during the fermentation process. Senior Assistant Professor Fukuuchi and Associate Professor Saegusa first quantified the purines contained in natto using a proprietary HPLC-UV purine analysis method they developed. Next, they created frozen sections of natto containing the sticky part ^* using conductive adhesive film (Kawamoto method), and by utilizing mass spectrometry imaging, they were the first in the world to reveal that among purine molecules, adenosine and guanosine are found in particularly high concentrations in the sticky part. The results of this research will be useful for nutritional management and disease prevention by devising ways to eat natto and other intake methods, and it is expected that mass spectrometry imaging will also be applied to visualizing the components contained in other foods.

These results were published online in the international scientific journal Food Chemistry on Wednesday, November 19th (with support from the Open Access Support Program). Co-first author Alex Affricano is an international student in the Graduate School of Pharmaceutical Sciences at our Graduate School (PhD course, September to December 2024).

• * The sticky part of natto is thought to be made up of polyglutamic acid, which is a combination of many glutamic acids produced by natto bacteria breaking down soy protein.

Click here to see the article published in the international scientific journal Food Chemistry
Click here for more information about Senior Assistant Professor Tomoko Fukuuchi
For more information about Associate Professor Daisuke Saegusa, please click here.

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