title: Rebaudiosides T and U, minor C-19 xylopyranosyl and arabinopyranosyl steviol glycoside derivatives from Stevia rebaudiana (Bertoni) Bertoni.
abstract: Two diterpene glycosides were isolated from a commercial Stevia rebaudiana leaf extract. One was found to be 13-[(2-O-β-d-glucopyranosyl-3-O-β-d-glucopyranosyl-β-d-glucopyranosyl)oxy]ent-kaur-16-en-19-oic acid-(2-O-β-d-xylopyranosyl-3-O-β-d-glucopyranosyl- β-d-glucopyranosyl) ester (rebaudioside T), whereas the other was determined to be 13-[(2-O-β-d-glucopyranosyl-3-O-β-d-glucopyranosyl-β-d-glucopyranosyl)oxy]ent-kaur-16-en-19-oic acid-(6-O-α-l-arabinopyranosyl-β-d-glucopyranosyl) ester (rebaudioside U). In addition, five C-19 sugar free derivatives were prepared and identified as follows: 13-[(2-O-α-l-rhamnopyranosyl-β-d-glucopyranosyl)]oxy]kaur-16-en-19-oic acid (dulcoside A1); 13-[(2-O-β-d-xylopyranosy-3-O-β-d-glucopyranosyl-β-d-glucopyranosyl)oxy]kaur-16-en-19-oic acid; 13-[(2-O-β-d-xylopyranosyl-β-d-glucopyranosyl-)oxy]kaur-16-en-19-oic acid; 13-[(2-O-β-d-glucopyranosyl-3-O-β-d-glucopyranosyl-β-d-xylopyranosyl-)oxy]kaur-16-en-19-oic acid (rebaudioside R1) and 13-[(2-O-6-deoxy-β-d-glucopyranosyl-3-O-β-d-glucopyranosyl-β-d-glucopyranosyl)oxy]kaur-16-en-19-oic acid, respectively. Chemical structures were determined by NMR experiments. HPLC analyses were also useful to differentiate different steviol-C13 sugar substituent patterns by elution position.
authors.affiliation: Ironstone Separations, Inc., Etta, Oxford, MS 38627, USA.
authors.forename: Wilmer H
authors.initials: WH
authors.lastname: Perera
authors.affiliation: Department of Chemistry, University of Florida, Gainesville, FL 32611, USA.
authors.forename: Ion
authors.initials: I
authors.lastname: Ghiviriga
authors.affiliation: Ironstone Separations, Inc., Etta, Oxford, MS 38627, USA.
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Rodenburg
authors.affiliation: Ironstone Separations, Inc., Etta, Oxford, MS 38627, USA.
authors.forename: Kamilla
authors.initials: K
authors.lastname: Alves
authors.affiliation: Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
authors.forename: John J
authors.initials: JJ
authors.lastname: Bowling
authors.affiliation: National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, University of Mississippi, University, MS 38677, USA.
authors.forename: Bharathi
authors.initials: B
authors.lastname: Avula
authors.affiliation: National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, University of Mississippi, University, MS 38677, USA; Division of Pharmacognosy, Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, University, MS 38677, USA.
authors.forename: Ikhlas A
authors.initials: IA
authors.lastname: Khan
authors.affiliation: Ironstone Separations, Inc., Etta, Oxford, MS 38627, USA. Electronic address: jdmcchesney@yahoo.com.
authors.forename: James D
authors.initials: JD
authors.lastname: McChesney
mesh_terms: D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification*; D045786:Diterpenes, Kaurane; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification*; D015394:Molecular Structure; D012503:Saponins / Q000032:analysis; D036625:Stevia / Q000737:chemistry*; D014315:Triterpenes / Q000032:analysis
chemical_list: D004224:Diterpenes; D045786:Diterpenes, Kaurane; D006027:Glycosides; D012503:Saponins; D014315:Triterpenes; C000614076:rebaudioside T; C000614077:rebaudioside U; C012042:steviol
keywords: Asteraceae; Stevia rebaudiana; Steviol glycosides