title: Two new flavonol glycosides from Otostegia limbata BENTH.
abstract: A BuOH-soluble part of the methanolic extract from the roots of Otostegia limbata yielded two new flavonol glycosides; kaempferol 3-O-[beta-D-glucopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->3)]-[beta-D-glucopyranosyl-(1-->4)]-alpha-L-rhamnopyranoside]-7-O-[alpha-L-rhamnopyranoside] (1) and kaempferol 3-O-[beta-D-glucopyranosyl-(1-->4)-beta-D-6'''''[4-hydroxy (E)-cinnamoyl]glucopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->2)]-alpha-L-rhamnopyranoside]-7-O-[alpha-L-rhamnopyranoside] (2). The structures of these compounds were elucidated by spectroscopic and chemical means. To the best of our knowledge, these are the largest flavonoids derivatives described so far from the genus Otostegia.
authors.affiliation: H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan.
authors.forename: Afsar
authors.initials: A
authors.lastname: Khan
authors.forename: Viqar Uddin
authors.initials: VU
authors.lastname: Ahmad
authors.forename: Umar
authors.initials: U
authors.lastname: Farooq
authors.forename: Sadia
authors.initials: S
authors.lastname: Bader
authors.forename: Saima
authors.initials: S
authors.lastname: Arshad
mesh_terms: D044948:Flavonols / Q000737:chemistry* / Q000302:isolation & purification; D006027:Glycosides / Q000737:chemistry* / Q000302:isolation & purification; D044949:Kaempferols / Q000737:chemistry* / Q000302:isolation & purification; D019686:Lamiaceae / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D009844:Oligosaccharides / Q000737:chemistry* / Q000302:isolation & purification; D018517:Plant Roots / Q000737:chemistry
chemical_list: D044948:Flavonols; D006027:Glycosides; D044949:Kaempferols; D009844:Oligosaccharides; C539539:kaempferol 3-O-(beta-D-glucopyranosyl-(1-4)-beta-D-6'''''(4-hydroxy (E)-cinnamoyl)glucopyranosyl-(1-3)-(beta-D-glucopyranosyl-(1-2))-alpha-L-rhamnopyranoside)-7-O-(alpha-L-rhamnopyranoside); C539538:kaempferol 3-O-beta-D-glucopyranosyl-(1-2)-(beta-D-glucopyranosyl-(1-3))-(beta-D-glucopyranosyl-(1-4))-(alpha-L-rhamnopyranoside)-7-O-(alpha-L-rhamnopyranoside)