title: Structure-antioxidant relationship of flavonoids from fermented rooibos.
abstract: Rooibos tea (Aspalathus linearis) contains different bioactive phenolic compounds such as dihydrochalcones, flavonols, flavanones, flavones, and flavanols. Flavonoids isolated from rooibos were subjected to different in vitro assays: Trolox equivalent antioxidant activity, LDL oxidation and Fremy's salt assays to determine the total antioxidant activity (TAA). Assay results were compared, and the structure-antioxidant relationship was investigated. A decoupled LDL oxidation test was established with the objective of having an assay adapted more to an in vivo situation. The different in vitro methods were coupled offline to HPLC-DAD. Results from these coupled offline methods were compared to the TAA to assess the usefulness of the coupling setup.
authors.affiliation: Institute of Chemistry, Food Chemistry, Martin Luther University, Halle-Wittenberg, Halle, Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: Krafczyk
authors.forename: Franziska
authors.initials: F
authors.lastname: Woyand
authors.forename: Marcus A
authors.initials: MA
authors.lastname: Glomb
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D036903:Aspalathus / Q000737:chemistry*; D005285:Fermentation; D005419:Flavonoids / Q000494:pharmacology*; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism; D010084:Oxidation-Reduction; D010936:Plant Extracts / Q000494:pharmacology*; D013329:Structure-Activity Relationship
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D008077:Lipoproteins, LDL; D010936:Plant Extracts; C099252:oxidized low density lipoprotein