STRUCTURAL CHARACTERIZATION AND HYDROLYSIS STUDIES OF REBAUDIOSIDE E, A MINOR SWEET COMPONENT OF STEVIA REBAUDIANA

摘要

From the commercial extract of the leaves of Stevia rebaudiana , a diterpene glycoside was isolated which was characterized as 13-[(2- O -β-D-glucopyranosyl-β-D-glucopyranosyl)oxy] ent -kaur-16-en-19-oic acid-(2- O -β-D-glucopyranosyl-β-D-glucopyranosyl) ester ( 1 ); also known as rebaudioside E. The complete 1 H and 13 C NMR assignments of rebaudioside E was achieved by the extensive 1D and 2D NMR ( 1 H and 13 C, COSY, HMQC, HMBC) as well as mass spectral data. Further, hydrolysis studies were performed on rebaudioside E using acid and enzymatic studies to identify aglycone and sugar residues in its structure.