Microbial transformation of the sweet sesquiterpene (+)-hernandulcin

(+)-Hernandulcin is a sweet bisabolane-type sesquiterpene first isolated from Lippia dulcis Trev. (Verbenaceae). This oily compound is 1000-1500 times sweeter than sucrose but with poor solubility in water. Microbial transformation was employed to improve its water solubility, and a variety of microorganisms were screened for their ability to convert (+)-hernandulcin to more polar metabolites. Scale-up fermentation with Glomerella cinguiata, a fungal strain, has resulted in the isolation of a more polar metabolite (2).