Isolation and Structural Characterization of a New Minor Penta β-D-Glucopyranosyl Diterpene from Stevia rebaudiana Bertoni

Abstract

From the commercial extract of the leaves of Stevia rebaudiana Bertoni, a new minor ent -kaurane diterpene glycoside having five β -D-glucopyranosyl units has been isolated. The chemical structur e of the new compound was characterized as 13-[(2- O - β -D-glu copyranosy l- β -D- glucopyranosyl) oxy] ent -kaur-16-en-19-oic acid-(2- O - β -D- glucopyranosyl-6- O - β -D-glucopyranosyl- β -D -glucopyranosyl) ester (1) on the basis of extensive 1D ( 1 H & 13 C) and 2D NMR (TOCSY, HMQC, and HMBC), and High Resolution (HR) mass spectroscopic data as well as hydrolysis studies.