Steviol glycosides from Stevia: biosynthesis pathway review and their application in foods and medicine.

Stevia rebaudiana, a perennial herb from the Asteraceae family, is known to the scientific world for its sweetness and steviol glycosides (SGs). SGs are the secondary metabolites responsible for the sweetness of Stevia. They are synthesized by SG biosynthesis pathway operating in the leaves. Most of the genes encoding the enzymes of this pathway have been cloned and characterized from Stevia. Out of various SGs, stevioside and rebaudioside A are the major metabolites. SGs including stevioside have also been synthesized by enzymes and microbial agents. These are non-mutagenic, non-toxic, antimicrobial, and do not show any remarkable side-effects upon consumption. Stevioside has many medical applications and its role against diabetes is most important. SGs have made Stevia an important part of the medicinal world as well as the food and beverage industry. This article presents an overview on Stevia and the importance of SGs.