title: HPLC-DAD-MS/MS profiling of antioxidant flavonoid glycosides in sea buckthorn (Hippophae rhamnoides L.) seeds.
abstract: This study was aimed at the chemical profiling of flavonoid glycosides in antioxidant (AO) fractions of sea buckthorn (Hippophae rhamnoides) seed. Seed fractions were evaluated for their DPPH, ABTS, superoxide and hydroxyl radical scavenging, ferric reduction, ferrous chelation and xanthine oxidase inhibitory capacities. HPLC-DAD-ESI-MS/MS analytical conditions for the profiling of seed flavonoids were optimized and the AO-rich fraction was analysed. Quercetin-3-O-rutinoside (5.9%), isorhamnetin-3-O-rutinoside (4.9%) and isorhamnetin-3-O-sophroside-7-O-rhamnoside (3.7%) were found as the major flavonoid glycosides in the fraction. Significant amounts of isorhamnetin-3-O-glucoside (2.8%), 3-O-sophroside-7-O-rhamnosides of quercetin (2.4%) and kaempherol (1.3%), and 3-O-glucoside-7-O-rhamnosides of quercetin (1.1%) and isorhamnetin (1.1%) along with their free forms: isorhamnetin (2.7%), quercetin (1.1%) and kaempherol (0.6%) were also found in the fraction. The identification of flavonoids as the major less polar AO phenolics in the seeds was rationalized by demonstrating the high AO activity of isorhamnetin, quercetin, kaempherol and quercetin-3-O-rutinoside.
authors.affiliation: Agroprocessing and Natural Products Division, National Institute for Interdisciplinary Science Technology (CSIR) , Thiruvananthapuram 19, Kerala, India. ranjith.arbr@gmail.com
authors.forename: Ranjith
authors.initials: R
authors.lastname: Arimboor
authors.forename: C
authors.initials: C
authors.lastname: Arumughan
mesh_terms: D000975:Antioxidants / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005419:Flavonoids / Q000737:chemistry*; D006027:Glycosides / Q000737:chemistry*; D031281:Hippophae / Q000737:chemistry*; D017665:Hydroxyl Radical; D007502:Iron Chelating Agents / Q000737:chemistry; D015394:Molecular Structure; D012639:Seeds / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D006027:Glycosides; D007502:Iron Chelating Agents; D017665:Hydroxyl Radical; D014969:Xanthine Oxidase