Licorice may aid battle against dental cavities

Compounds isolated from licorice root (Glycyrrhiza uralensis) have been shown in bioassays to exhibit potent antibacterial activity against Streptococcus mutans, an oral pathogen that causes tooth decay (J. Nat. Prod. 2006, 69, 121). That means chewing on licorice candy may help reduce cavities or combat other problem bacteria, researchers speculate. Wenyuan Shi, Qing-Yi Lu, and their colleagues at the University of California, Los Angeles, discovered two new pterocarpene compounds (glycyrrhizol A and B) and isolated four previously known flavonoids from the root and characterized the compounds by several spectroscopic methods. The team used bioassays to test the antibacterial properties of the compounds; glycyrrhizol A (shown) exhibited the strongest activity against S. mutans. Licorice is an important herb in Chinese medicine, and its derivatives are used worldwide as flavoring and sweetening agents in tobacco, gum, candy, and beverages. Although further testing is needed, toothpaste companies are interested in the new compounds, Shi says.