**Approaches toward the Separation, Modification, Identification and Scale up Purification of Tetracyclic Diterpene Glycosides from** *Stevia rebaudiana* **(Bertoni) Bertoni**

**Wilmer H. Perera 1,\* and James D. McChesney 2,\***


**Abstract:** *Stevia rebaudiana* (Bertoni) Bertoni is a plant species native to Brazil and Paraguay wellknown by the sweet taste of their leaves. Since the recognition of rebaudioside A and other steviol glycosides as generally recognized as safe by the United States Food and Drug Administration in 2008 and grant of marketing approval by the European Union in 2011, the species has been widely cultivated and studied in several countries. Several efforts have been dedicated to the isolation and structure elucidation of minor components searching for novel non-caloric sugar substitutes with improved organoleptic properties. The present review provides an overview of the main chemical approaches found in the literature for identification and structural differentiation of diterpene glycosides from *Stevia rebaudiana*: High-performance Thin-Layer Chromatography, High-Performance Liquid Chromatography, Electrospray Ionization Mass Spectrometry and Nuclear Magnetic Resonance Spectroscopy. Modification of diterpene glycosides by chemical and enzymatic reactions together with some strategies to scale up of the purification process saving costs are also discussed. A list of natural diterpene glycosides, some examples of chemically modified and of enzymatically modified diterpene glycosides reported from 1931 to February 2021 were compiled using the scientific databases Google Scholar, ScienceDirect and PubMed.

**Keywords:** *Stevia rebaudiana*; HPTLC; HPLC methods; mass spectrometry dissociation pattern; NMR; endocyclic and exocyclic diterpene glycosides; scale up
