title: Synthesis of rebaudioside-A by enzymatic transglycosylation of stevioside present in the leaves of Stevia rebaudiana Bertoni.
abstract: 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=35.01 μg/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.
authors.affiliation: Medicinal Chemistry and Pharmacology Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India. Electronic address: abrao@iict.res.in.
authors.forename: Bhaskar Rao
authors.initials: BR
authors.lastname: Adari
authors.affiliation: Medicinal Chemistry and Pharmacology Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India.
authors.forename: Sateesh
authors.initials: S
authors.lastname: Alavala
authors.affiliation: Medicinal Chemistry and Pharmacology Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India.
authors.forename: Sara A
authors.initials: SA
authors.lastname: George
authors.affiliation: Medicinal Chemistry and Pharmacology Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India.
authors.forename: Harshadas M
authors.initials: HM
authors.lastname: Meshram
authors.affiliation: Medicinal Chemistry and Pharmacology Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India.
authors.forename: Ashok K
authors.initials: AK
authors.lastname: Tiwari
authors.affiliation: Centre for NMR and Structural Chemistry Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India.
authors.forename: Akella V S
authors.initials: AV
authors.lastname: Sarma
mesh_terms: D002480:Cellulase; D045786:Diterpenes, Kaurane / Q000737:chemistry*; D005503:Food Additives / Q000032:analysis; D005960:Glucosides / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*; D036625:Stevia / Q000737:chemistry*; D013549:Sweetening Agents / Q000737:chemistry*
chemical_list: D045786:Diterpenes, Kaurane; D005503:Food Additives; D005960:Glucosides; D013549:Sweetening Agents; C012043:stevioside; C025474:rebaudioside A; D002480:Cellulase
keywords: Cellulase; Glucosyl donors; Rebaudioside-A; Rebaudioside-A (PubChem CID:6918840); Stevia leaves; Stevioside (PubChem CID:442089); Transglycosylation