KAIST

<(From left) Dr. Neetu Singh, Ph.D candidate Haneul Im, Dr. Seongyeon Kwon (IBS) (Back) Professor YunJung Baek>

Vitamin B2 (riboflavin), which we consume, acts as an important coenzyme that helps food convert into energy within the body. Korean researchers have successfully created a new artificial enzyme for the first time in the world by combining this riboflavin (flavin) with metal, adding the metal's reaction-controlling ability to riboflavin's electron-transfer function. This technology is expected to operate more precisely and stably than natural enzymes, demonstrating potential for use in various fields such as energy production, environmental purification, and new drug development.

The research team led by Professor Yunjung Baek of KAIST Department of Chemistry, in collaboration with Dr. Seongyeon Kwon of the Institute for Basic Science, announced on the 11th of November that they have succeeded in synthesizing a new molecular system that allows flavin to bind with metal ions.

Until now, scientists have long been unable to realize "flavin combined with metal" because flavin has a structural limitation—a complex ring structure entangled with nitrogen and oxygen—which makes it difficult for a metal to selectively bind.

To overcome this limitation, the research team designed a binding site for the metal within the flavin at the molecular level and applied a metallochemical approach that precisely arranges the ligand structure that traps the metal.

Through this, they successfully and stably synthesized the flavin-metal complex by delicately controlling the electronic and spatial interactions around the metal.

This achievement is the first case that integrates flavin's inherent properties and metal's reactivity into a single system, opening up the possibility for the development of 'metal-based artificial enzymes' that finely tune chemical reactions.

Professor Yunjung Baek stated, "We have moved beyond the limitations of naturally occurring flavin and expanded a biomolecule into a new component of metallochemistry. This research suggests a new direction for the design of next-generation catalysts and energy conversion materials based on biomolecules."

This achievement, in which Dr. Neetu Singh and Ph.D candidate Haneul Im of KAIST Department of Chemistry participated as co-first authors, was published in the international journal Inorganic Chemistry, issued by the American Chemical Society (ACS), on November 5th. It was recognized for its creativity and completeness and was selected as the cover article. Furthermore, it was chosen as an ACS Editors’ Choice—a representative paper selected once a day from all 90+ journals published by ACS—acknowledging the importance of the research.

• Article Title: Tautomerizable Flavin Ligands for Constructing Primary and Secondary Coordination Spheres, DOI: 10.1021/acs.inorgchem.5c03941
• Author Information: Total 5 authors including Neetu Singh (KAIST, Co-first Author), Haneul Im (KAIST, Co-first Author), Seongyeon Kwon (IBS, Co-second Author), Dongwook Kim (IBS, Co-third Author), and Yunjung Baek (KAIST, Corresponding Author).

<Cover Article Selection Photo for Inorganic Chemistry, an International Academic Journal Published by the American Chemical Society>

This research was supported by the 'Excellent New Researcher' project of the Basic Research Program for Individuals funded by the Ministry of Science and ICT, and the 'Materials and Components Development Program' supported by the Ministry of Trade, Industry and Energy.