Chiba Halogen Science: Halogen-Linkage of Molecular Functions
Professor Takayoshi Arai
Iodine is one of the few precious elemental resources exported by Japan. Japan produces approximately 30% of the world's iodine (the second largest in the world), of which 75% is from Chiba prefecture. Owing to the importance of natural iodine resources in Japan, Chiba University established the "Chiba Iodine Resource Innovation Center (CIRIC)" to promote iodine chemistry through industry-academia collaboration. Comprehensive study of halogens is essential to discover novel and advanced applications of iodine. Hence, in addition to iodine chemistry, we also conduct research on other halogens such as bromine (Br), chlorine (Cl), and fluorine (F), to accumulate knowledge, generate new insists and attain achievements in halogen science. This cutting-edge interdisciplinary research creates a collaborative network of "Chiba Halogen Science," with the aim of establishing "Halogen Medicine."
Advanced molecular medicine technologies, such as photoimmunotherapy, have been attracting a great deal of attention in recent years. These technologies include diagnosis with fluorescent probes that specifically light up cancer cells, in vivo catalytic therapy that chemically synthesizes drugs to target cancer cells, and administration of compounds or nanoparticles which preferentially accumulate in cancer cells and aid in their targeted laser ablation. These diagnostic and therapeutic methods employ a wide variety of halogenated compounds. Interestingly, the principal functions of these compounds such as fluorescence and catalytic activity, are known to vary with the halogen type, as shown in the figure.
Therefore, this research aims to develop a novel technique for diagnosis and therapy called "Halogen tuning," where we can modulate the in vivo catalytic activity, fluorescence, and biological activity of these compounds by controlling the types and positions of the halogen atoms.
Our ultimate goal to establish “Halogen medicine” which synchronizes "diagnosis" and "treatment" on a single molecule platform will be achieved, once we realize a single "Multifunctional Molecule," which can be used for all these purposes, employing halogen tuning.