Spectral Analysis and Chemical Studies of the Sweet Constituent, Rebaudioside A

Aim: To study NMR spectral analysis and hydrolysis products of Rebaudioside A (1) that has been isolated from Stevia rebaudiana.
Study Design: Acquiring NMR and high resolution mass spectral (HRMS) data of Rebaudioside A for structural characterization, and identification of hydrolysis products.
Place of Study: Organic Chemistry Department of The Coca-Cola Company, Atlanta, GA 30313, USA.
Methodology: The 1D (1H &13C) and 2D (COSY, HSQC, and HMBC) NMR spectral data of was acquired using Varian Unity Plus 600 MHz instrument using standard pulse sequences.Hydrolysis studies were performed on Rebaudioside A using acid, base and enzymatic studies to identify partial degradation products, aglycone and sugar residues.
Results: The proton and carbon values of Rebaudioside A were assigned based on NMR and HRMS data as well as chemical studies. The aglycone was identified as steviol on the basis of enzymatic hydrolysis, sugar was identified as D-glucose from acid hydrolysis and the partial hydrolyzed product was identified as Rebaudioside B from alkaline hydrolysis.