title: Flavonol Glycosides in Currant Leaves and Variation with Growth Season, Growth Location, and Leaf Position.
abstract: Flavonol glycosides (FG) were analyzed in the leaves of six currant cultivars (Ribes spp.) with HPLC-DAD, HPLC-MS/MS, and NMR. The average amounts of the 12 major, identified FG constituted 86-93% (9.6-14.1 mg/g DW) of the total of 27 FG found. Quercetin and kaempferol were the major aglycones with trace amounts of myricetin. Quercetin-3-O-(2,6-α-dirhamnopyranosyl-β-glucopyranoside), quercetin-3-O-(2-β-xylopyranosyl-6-α-rhamnopyranosyl-β-glucopyranoside), and kaempferol-3-O-(3,6-α-dirhamnopyranosyl-β-glucopyranoside) were identified for the first time in currant leaves and existed in a white currant cultivar 'White Dutch' only. Kaempferol-3-O-β-(6'-malonyl)glucopyranoside was also a new compound existing in abundance in five cultivars but not in the white one. The results show the primary importance of the genetic background of the cultivars. The content of malonylated FG of special importance in cardiovascular health decreased regularly during summer. Time of collection and leaf position were more prominent factors affecting the composition than were the year of harvest or the growth latitude. Randomly collected leaves differed in their FG profiles from those collected from the middle position of new branches.
authors.affiliation: Food Chemistry and Food Development, Department of Biochemistry, §Instrument Centre, Department of Chemistry, and #The Kevo Subarctic Research Institute, University of Turku , FI-20014 Turku, Finland.
authors.forename: Wei
authors.initials: W
authors.lastname: Yang
authors.affiliation: Food Chemistry and Food Development, Department of Biochemistry, §Instrument Centre, Department of Chemistry, and #The Kevo Subarctic Research Institute, University of Turku , FI-20014 Turku, Finland.
authors.forename: Aino-Liisa
authors.initials: AL
authors.lastname: Alanne
authors.affiliation: Food Chemistry and Food Development, Department of Biochemistry, §Instrument Centre, Department of Chemistry, and #The Kevo Subarctic Research Institute, University of Turku , FI-20014 Turku, Finland.
authors.forename: Pengzhan
authors.initials: P
authors.lastname: Liu
authors.affiliation: Food Chemistry and Food Development, Department of Biochemistry, §Instrument Centre, Department of Chemistry, and #The Kevo Subarctic Research Institute, University of Turku , FI-20014 Turku, Finland.
authors.forename: Heikki
authors.initials: H
authors.lastname: Kallio
authors.affiliation: Food Chemistry and Food Development, Department of Biochemistry, §Instrument Centre, Department of Chemistry, and #The Kevo Subarctic Research Institute, University of Turku , FI-20014 Turku, Finland.
authors.forename: Baoru
authors.initials: B
authors.lastname: Yang
mesh_terms: D002851:Chromatography, High Pressure Liquid; D044948:Flavonols / Q000737:chemistry*; D006027:Glycosides / Q000737:chemistry*; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry* / Q000254:growth & development; D031965:Ribes / Q000737:chemistry / Q000254:growth & development*; D012621:Seasons; D053719:Tandem Mass Spectrometry
chemical_list: D044948:Flavonols; D006027:Glycosides; D010936:Plant Extracts
keywords: 1H and 13C NMR; HPLC-MS/MS; Ribes nigrum; Ribes rubrum; flavonol glycosides; growth latitude; leaves; seasonal variation