title: Inter-population and inter-organ distribution of the main polyphenolic compounds of Epilobium angustifolium.
abstract: Rosebay willowherb (Epilobium angustifolium) contains large amounts of polyphenolic compounds, including tellimagrandin I-based oligomeric ellagitannins (ETs). The aim of this study was to assess the interpopulational and inter-organ variability of the polyphenol fingerprint of E. angustifolium. Seven ETs, 11 flavonol glycosides and neochlorogenic acid were quantified by UHPLC-DAD-ESI-QqQ-MS in the leaves, flowers and stem parts of plants from 10 populations. Total polyphenol content of leaves and flowers ranged from 150 to 200 mg/g dry wt, of which 90% was constituted by dimeric to heptameric ETs. Flowers contained, on average, 10% more oenothein B (dimeric ET) and 2 times less oenothein A (trimeric ET) than leaves. Tetrameric and pentameric ETs exhibited rather similar levels in leaves and flowers whereas hexameric and heptameric were 3-4 times more abundant in flowers than in leaves. Quercetin-3-O-rhamnoside, myricetin-3-O-rhamnoside and kaempferol-3-O-rhamnoside were specific to flower tissue and were absent from leaves. The inflorescence stem showed the highest content in total polyphenols with an average of 250 mg/g dry wt and contained remarkably large amounts of oenothein B and A. Polyphenol content steadily decreased along the inflorescence stem and reached its lowest level in the vegetative part of the stem. The interpopulational variability of most polyphenols was within a two- to threefold range across the 10 sampled populations. Myricetin-3-O-glucoside and myricetin-3-O-glucuronide, however, showed a more population-specific distribution with concentrations varying from 0 to 2.3 mg/g dry wt. Finally, this study showed that the levels of oenothein B and A in the plant are not interdependent but that their relative abundance is constant within a population.
authors.affiliation: Laboratory of Organic Chemistry and Chemical Biology, Department of Chemistry, University of Turku, Turku, FI-20014, Finland. Electronic address: nicolas.baert@utu.fi.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Baert
authors.affiliation: Laboratory of Organic Chemistry and Chemical Biology, Department of Chemistry, University of Turku, Turku, FI-20014, Finland.
authors.forename: Jorma
authors.initials: J
authors.lastname: Kim
authors.affiliation: Laboratory of Organic Chemistry and Chemical Biology, Department of Chemistry, University of Turku, Turku, FI-20014, Finland.
authors.forename: Maarit
authors.initials: M
authors.lastname: Karonen
authors.affiliation: Laboratory of Organic Chemistry and Chemical Biology, Department of Chemistry, University of Turku, Turku, FI-20014, Finland.
authors.forename: Juha-Pekka
authors.initials: JP
authors.lastname: Salminen
mesh_terms: D031666:Epilobium / Q000737:chemistry*; D005419:Flavonoids / Q000032:analysis; D044948:Flavonols / Q000032:analysis; D005707:Gallic Acid / Q000031:analogs & derivatives / Q000032:analysis; D005960:Glucosides / Q000032:analysis; D006027:Glycosides / Q000032:analysis; D047348:Hydrolyzable Tannins / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism; D044949:Kaempferols / Q000032:analysis; D008362:Mannosides / Q000032:analysis; D029594:Onagraceae / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry; D059808:Polyphenols / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D011794:Quercetin / Q000031:analogs & derivatives / Q000032:analysis
chemical_list: D005419:Flavonoids; D044948:Flavonols; D005960:Glucosides; D006027:Glycosides; D047348:Hydrolyzable Tannins; D044949:Kaempferols; D008362:Mannosides; D059808:Polyphenols; C470066:kaempferol 3-O-rhamnoside; C529905:myricetin-3-O-rhamnoside; C080077:oenothein B; C071081:oenothein A; C012526:quercitrin; D005707:Gallic Acid; C040015:myricetin; C072578:myricetin 3-O-glucuronide; C087926:tellimagrandin I; D011794:Quercetin
keywords: Epilobium angustifolium; Flavonol glycosides; Oligomeric ellagitannins; Onagraceae; Oxidised oenothein A; Population study