title: Antioxidant study of flavonoid derivatives from the aerial parts of Rhus natalensis growing in Saudi Arabia.
abstract: Phytochemical study of the CH(2)Cl(2) soluble fraction of the aerial parts of R. natalensis resulted in the isolation and identification of six flavonoid derivatives, β-amyrin and β-sitosterol glucoside (daucosterol). The isolated compounds were identified utilizing physical, chemical and different spectral methods including UV, 1D- 2D-NMR and MS. The compounds were identified as four flavanones; 7-O-methyl hesperetin (1), 7-O-methyl naringenin (4), (-)-homoeriodictyol (eriodictyonone) (5), eriodictyol-7-methyl ether (6) and two flavones; 7-O-methyl isokaemferide (2) and genkwanin (3). The isolated compounds as well as some available standards representing structurally similar flavones and flavanones were used to study their antioxidant potential using DPPH and try to explore the impact of structures on the antioxidant activity. In other assays flavanones were less active than flavones as antioxidant due to lack of the C-4 carbonyl group in conjugation with 2,3-double bond. However, in DPPH assay based on the ability of molecules to donate hydrogen flavanones were found more active than flavones.
authors.affiliation: Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, Kingdom of Saudi Arabia.
authors.forename: Saleh Ibrahim
authors.initials: SI
authors.lastname: Alqasoumi
authors.affiliation: Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, Kingdom of Saudi Arabia.
authors.forename: Omer Ahmed
authors.initials: OA
authors.lastname: Basudan
authors.affiliation: Department of Pharmacognosy, College of Pharmacy, Salman Bin Abdulaziz University, Al-Kharj , Saudi Arabia.
authors.forename: Prawez
authors.initials: P
authors.lastname: Alam
authors.affiliation: Department of Pharmacognosy, College of Pharmacy, Alexandria University, Alexandria, Egypt.
authors.forename: Maged Saad
authors.initials: MS
authors.lastname: Abdel-Kader
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D035261:Plant Components, Aerial; D029045:Rhus / Q000737:chemistry*; D012529:Saudi Arabia
chemical_list: D000975:Antioxidants; D005419:Flavonoids