Synthesis of rebaudioside-A by enzymatic transglycosylation of stevioside present in the leaves of Stevia rebaudiana Bertoni

• Published in: Food chemistry Vol. 200; pp. 154 - 158
• Main Authors: Adari, Bhaskar Rao, Alavala, Sateesh, George, Sara A., Meshram, Harshadas M., Tiwari, Ashok K., Sarma, Akella V.S.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-06-2016
• Subjects: Cellulase; Diterpenes, Kaurane - chemistry; Food Additives - analysis; Glucosides - chemistry; Glucosyl donors; Plant Leaves - chemistry; Rebaudioside-A; Stevia - chemistry; Stevia leaves; Sweetening Agents - chemistry; Transglycosylation; Rebaudioside-A (PubChem CID:6918840); Stevia leaves; Transglycosylation; Cellulase; Stevioside (PubChem CID:442089); Rebaudioside-A; Glucosyl donors
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2016.01.033

•Enzyme mediated transglycosylation of stevioside to rebaudioside-A.•The glucosyl moiety transglycosylated stereospecifically to get 13-O-β-stevioside.•The rebaudioside-A content in the pre-treated stevia leaves increased from 4% to 66%.•95% pure rebaudioside-A was obtained by multiple column chromatography.
Rebaudioside-A is the second most abundant sweet diterpene glycoside (1–3%) present in the leaves of Stevia rebaudiana Bertoni, and is now being considered as a possible sucrose substitute due to its pleasant organoleptic properties and associated health benefits. In the present study, a novel in situ enzymatic transglycosylation of stevioside has been developed by pre-treating the stevia leaves with cellulase and adding soluble starch as the glucosyl donor. The results confirm that the transglycosylation of stevioside led to an enrichment in the rebaudioside-A content from 4% to 66%. This was further purified by multiple column chromatography to obtain 95% pure rebaudioside-A. The isolated rebaudioside-A showed concentration-dependent α-glucosidase inhibitory activity with IC50=35.01μg/ml. Thus the study highlights the biotransformation of stevioside present in stevia leaves to rebaudioside-A by a simple, inexpensive and eco-friendly process that has commercial potential.