title: Two New Flavonoids and Biological Activity of Astragalus abyssinicus (Hochst.) Steud. ex A. Rich. Aerial Parts.
abstract: 2 new flavonoid glycosides, kaempferol 3-O-(4",6"-di-O-α-L-rhamnopyranosyl)-β-D-glucopyranoside (1) and quercetin 3-O-(4",6"-di-O-α-L-rhamnopyranosyl)-β-D-glucopyranoside (2), were isolated from the n-butanol soluble fraction of the methanol extract (BF) of Astragalus abyssinicus aerial parts, together with 3 known compounds, rutin (3), kaempferol 3-O-β-D-rutinoside (4) and 5,7,4'-trihydroxy-3'-methoxyisoflavone (5). The structures of the isolated compounds were characterized on the basis of UV, NMR and negative ESI-MS analyses. The BF fraction showed in vitro weak antibacterial activity against Staphylococcus aureus, while 2 and 3 exhibited in vitro antioxidant activity higher than ascorbic acid using DPPH free radical scavenging activity method.
authors.affiliation: Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh Saudi Arabia.
authors.forename: R A
authors.initials: RA
authors.lastname: El Dib
authors.affiliation: Department of Pharmacognosy, Faculty of Pharmacy, Helwan University, Cairo, Egypt.
authors.forename: H S M
authors.initials: HS
authors.lastname: Soliman
authors.affiliation: Department of Pharmacognosy, College of Pharmacy, Al-Azhar University, Cairo, Egypt.
authors.forename: M H
authors.initials: MH
authors.lastname: Hussein
authors.affiliation: Department of Pharmacognosy, College of Pharmacy, Najran Univeristy, Najran, Kingdom of Saudi Arabia.
authors.forename: H G
authors.initials: HG
authors.lastname: Attia
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D027883:Astragalus Plant / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D044949:Kaempferols / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D035261:Plant Components, Aerial / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D011794:Quercetin / Q000031:analogs & derivatives / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D014312:Trisaccharides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D006027:Glycosides; D044949:Kaempferols; D010936:Plant Extracts; D014312:Trisaccharides; C000606710:kaempferol 3-O-(4',6'-di-O-rhamnopyranosyl)glucopyranoside; C000606711:quercetin 3-O-(4',6'-di-O-rhamnopyranosyl)glucopyranoside; D011794:Quercetin