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Rebaudiosides R and S, Minor Diterpene Glycosides from the Leaves of Stevia rebaudiana

Author:
Ibrahim, Mohamed A., Rodenburg, Douglas L., Alves, Kamilla, Perera, Wilmer H., Fronczek, Frank R., Bowling, John, McChesney, James D.
Source:
Journal of natural products 2016 v.79 no.5 pp. 1468-1472
ISSN:
1520-6025
Subject:
Stevia rebaudiana, X-ray diffraction, chemical structure, diterpenoids, glycosides, leaves, nuclear magnetic resonance spectroscopy
Abstract:
Two new diterpene glycosides have been isolated from a commercial extract of the leaves of Stevia rebaudiana. Compound 1 was shown to be 13-[(2-O-β-d-glucopyranosyl-3-O-β-d-glucopyranosyl-β-d-xylopyranosyl)oxy]ent-kaur-16-en-19-oic acid β-d-glucopyranosyl ester (rebaudioside R), while compound 2 was determined to be 13-[(2-O-α-d-glucopyranosyl-β-d-glucopyranosyl)oxy]ent-kaur-16-en-19-oic acid 2-O-α-l-rhamnopyranosyl-β-d-glucopyranosyl ester (rebaudioside S). Six additional known compounds were identified, dulcoside B, 13-[(2-O-β-d-xylopyranosyl-β-d-glucopyranosyl)oxy]ent-kaur-16-en-19-oic acid β-d-glucopyranosyl ester, eugenol diglucoside, rebaudioside G, 13-[(2-O-6-deoxy-β-d-glucopyranosyl-3-O-β-d-glucopyranosyl-β-d-glucopyranosyl)oxy]ent-kaur-16-en-19-oic acid β-d-glucopyranosyl ester, and rebaudioside D (3), respectively. The structures of 1 and 2 were determined based on comprehensive 1D and 2D NMR (COSY, HSQC, and HMBC) studies. A high-quality crystal of compound 3 allowed confirmation of its structure by X-ray diffraction.
Agid:
5498521