title: Profiling of phenolic compounds and antioxidant activity of dry extracts from the selected Sorbus species.
abstract: The antioxidant efficiency of dry extracts from inflorescences and/or leaves of seven Sorbus species was studied using four in vitro tests of SET (single electron transfer) and HAT-type (hydrogen atom transfer) mechanisms. The 70% methanol extracts and its diethyl ether, ethyl acetate, n-butanol and water fractions were tested in parallel with the phenolic standards, e.g., caffeic acid, quercetin, BHA, BHT, and Trolox. The SET-type activity of the extracts depended primarily on the extraction solvent. The most valuable extracts were n-butanol and ethyl acetate ones, which activity was high in the DPPH (EC(50) = 3.2-5.2 μg/mL), TEAC (2.8-4.0 mmol Trolox/g), and FRAP (9.8-13.7 mmol Fe2+/g) tests, and strongly correlated with the total phenolic levels (39.6-58.2% of gallic acid equivalents). The HPLC-PDA analysis of the extracts led to the identification of chlorogenic acid, isoquercitrin, hyperoside, rutin, quercetin 3-O-sophoroside, and sexangularetin 3-O-β-D-glucopyranoside as the main components. Apart from flavonoids and hydroxycinnamic acids, proanthocyanidins have also a significant impact on the SET-type activity. The HAT-reactivity of the extracts in the linoleic acid peroxidation test (IC(50) = 36.9-228.3 μg/mL) depended more strongly on the plant tissue than on the extraction solvent, and its correlation with the phenolic content was weak. Both SET and HAT-type activity of the most potent Sorbus extracts was comparable with the activity of the standards, indicating their great potential as effective sources for health products.
authors.affiliation: Department of Pharmacognosy, Faculty of Pharmacy, Medical University of Lodz, Muszyńskiego 1, 90 151 Lodz, Poland. monika.olszewska@umed.lodz.pl
authors.forename: Monika A
authors.initials: MA
authors.lastname: Olszewska
authors.forename: Anna
authors.initials: A
authors.lastname: Presler
authors.forename: Piotr
authors.initials: P
authors.lastname: Michel
mesh_terms: D000085:Acetates / Q000737:chemistry; D052160:Benzothiazoles / Q000737:chemistry; D001713:Biphenyl Compounds / Q000737:chemistry; D000440:Butanols / Q000737:chemistry; D002725:Chloroform / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D003373:Coumaric Acids / Q000737:chemistry / Q000302:isolation & purification; D004986:Ether / Q000737:chemistry; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000302:isolation & purification; D006801:Humans; D015227:Lipid Peroxidation; D000432:Methanol / Q000737:chemistry; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry* / Q000302:isolation & purification; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification; D012015:Reference Standards; D052616:Solid Phase Extraction / Q000379:methods; D012997:Solvents / Q000737:chemistry; D031994:Sorbus / Q000737:chemistry*; D013451:Sulfonic Acids / Q000737:chemistry
chemical_list: D000085:Acetates; D052160:Benzothiazoles; D001713:Biphenyl Compounds; D000440:Butanols; D003373:Coumaric Acids; D016166:Free Radical Scavengers; D010636:Phenols; D010851:Picrates; D010936:Plant Extracts; D012997:Solvents; D013451:Sulfonic Acids; D004986:Ether; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; C007650:ethyl acetate; D002725:Chloroform; C004931:1,1-diphenyl-2-picrylhydrazyl; D000432:Methanol