title: Antioxidant activity and chemical composition of Sideritis libanotica Labill. ssp. linearis (Bentham) Borm. (Lamiaceae).
abstract: Sideritis libanotica ssp. linearis was screened for the isolation of new natural antioxidant compounds. The antioxidant activity of flavones obtained from the methanol extract of the plant was evaluated in vitro using total antioxidant, reduction power and free radical scavenging activity. Results were compared with the positive controls of antioxidant standards (α-tocopherol and butylated hydroxytoluene). The results indicate that the flavones possess a higher antioxidant activity when compared to the other components in the plant. The lowest antioxidant activity was observed in fatty acids (FAs) and hydrocarbons. The FAs were methylated with MeOH and KOH and analysed by GC-MS. The structures of the isolated compounds were established based on spectroscopic evidence (NMR, GC-MS, HPLC, IR and UV). In this work, the isolated pure flavone (3'-O-methylhypolaetin 7-O-[6″'-O-acetyl-β-D-allopyranosyl-(1 → 2)]-6″-O-acetyl-β-D-glucopyranoside) was found to possess the highest antioxidant activity.
authors.affiliation: Laboratory of Plant Research, Department of Chemistry, Faculty of Science and Art, Gaziosmanpasa University, Taçlıçiftlik Campus, 60240 Tokat, Turkey. idemirtas@gop.edu.tr
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Demirtas
authors.forename: Bulent
authors.initials: B
authors.lastname: Ayhan
authors.forename: Ayse
authors.initials: A
authors.lastname: Sahin
authors.forename: Hüseyin
authors.initials: H
authors.lastname: Aksit
authors.forename: Mahfuz
authors.initials: M
authors.lastname: Elmastas
authors.forename: Isa
authors.initials: I
authors.lastname: Telci
mesh_terms: D002084:Butylated Hydroxytoluene / Q000737:chemistry; D005227:Fatty Acids / Q000737:chemistry / Q000302:isolation & purification; D047309:Flavones / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D008401:Gas Chromatography-Mass Spectrometry; D005960:Glucosides / Q000737:chemistry* / Q000302:isolation & purification; D006838:Hydrocarbons / Q000737:chemistry / Q000302:isolation & purification; D035261:Plant Components, Aerial / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry; D031365:Sideritis / Q000737:chemistry*; D013057:Spectrum Analysis / Q000379:methods; D024502:alpha-Tocopherol / Q000737:chemistry
chemical_list: C570266:3'-O-methylhypolaetin-7-O-(6'''-O-acetyl-beta-D-allopyranosyl-(1-2))-6''-O-acetyl-beta-D-glucopyranoside; D005227:Fatty Acids; D047309:Flavones; D016166:Free Radical Scavengers; D005960:Glucosides; D006838:Hydrocarbons; D010936:Plant Extracts; D002084:Butylated Hydroxytoluene; D024502:alpha-Tocopherol