Rebaudiosides R and S, Minor Diterpene Glycosides from the Leaves of Stevia rebaudiana.
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.
Ironstone Separations, Inc. , Etta, Mississippi 38627, United States.|Department of Chemistry of Natural Compounds, National Research Center , Dokki 12622, Cairo, Egypt.
Mohamed A
MA
Ibrahim
Ironstone Separations, Inc. , Etta, Mississippi 38627, United States.
Douglas L
DL
Rodenburg
Ironstone Separations, Inc. , Etta, Mississippi 38627, United States.
Kamilla
K
Alves
Ironstone Separations, Inc. , Etta, Mississippi 38627, United States.
Wilmer H
WH
Perera
Department of Chemistry, Louisiana State University , Baton Rouge, Louisiana 70803, United States.
Frank R
FR
Fronczek
Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital , Memphis, Tennessee 38105, United States.
John
J
Bowling
Ironstone Separations, Inc. , Etta, Mississippi 38627, United States.
James D
JD
McChesney
D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification; D045786:Diterpenes, Kaurane / Q000737:chemistry / Q000302:isolation & purification*; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification*; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D018515:Plant Leaves / Q000737:chemistry; D013237:Stereoisomerism; D036625:Stevia / Q000737:chemistry*
D004224:Diterpenes; D045786:Diterpenes, Kaurane; D006027:Glycosides; C000619752:rebaudioside R; C000619753:rebaudioside S; C014341:argyrophilic acid