Isolation, characterization and sensory evaluation of a Hexa beta-D-glucopyranosyl diterpene from Stevia rebaudiana.

From the extract of the leaves of Stevia rebaudiana Bertoni, a diterpene glycoside was isolated which was identified as 13-[(2-O-beta-D-glucopyranosyl-3-O-beta-D-glucopyranosyl-beta-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-(2-O-beta-D-glucopyranosyl-3-O-beta-D-glucopyranosyl-D-glucopyranosyl) ester (1). The complete 1H and 13C NMR assignment of 1 is reported for the first time, from extensive NMR (1H and 13C, COSY, HSQC, and HMBC) and mass spectral data. Also, we report the sensory evaluation of 1 against sucrose for the sweetness property of this molecule.