Chemoenzymatic oxygenation method for sesquiterpenoid synthesis based on Fe-chelate and ferric-chelate reductase.

Sesquiterpenoids are one of the most diverse groups in natural compounds with various chemical structures and bioactivities. In our previous work, we developed the chemoenzymatic oxygenation method based on the combination of Fe(II)-EDTA and ferric-chelate reductase that could synthesize (-)-rotundone, a key aroma sesquiterpenoid of black pepper. Fe(II)-EDTA catalyzed the oxygenation of sesquiterpene to sesquiterpenoid, and ferric-chelate reductase catalyzed the supply and regeneration of Fe(II)-EDTA in this system.

Development of a synthesis method for odor sesquiterpenoid, (-)-rotundone, using non-heme Fe-chelate catalyst and ferric-chelate reductase.

(-)-Rotundone, a sesquiterpenoid that has a characteristic woody and peppery odor, is a key aroma component of spicy foodstuffs, such as black pepper and Australian Shiraz wine. (-)-Rotundone shows the lowest level of odor threshold in natural compounds and remarkably improves the quality of various fruit flavors. To develop a method for the synthesis of (-)-rotundone, we focused on non-heme Fe-chelates, which are biomimetic catalysts of the active center of oxygenases and enzymatic supply and regeneration of those catalysts.