title: Isolation and structural characterization of unusual pyranoanthocyanins and related anthocyanins from Staghorn sumac (Rhus typhina L.) via UPLC-ESI-MS, (1)H, (13)C, and 2D NMR spectroscopy.
abstract: The six major anthocyanins found in the burgundy coloured fruits of Staghorn sumac (Rhus typhina L.) were isolated and the structures of four compounds were determined by NMR spectroscopic methods as being: 7-O-methyl-delphinidin-3-O-(2″galloyl)-β-d-galactopyranoside; 7-O-methyl-cyanidin-3-O-(2″galloyl)-β-d-galactopyranoside; 7-O-methyl-delphinidin-3-O-(2″'galloyl)-β-d-galactopyranoside-4-vinyl-catechol-3″-O-β-d-glucopyranoside; and 7-O-methyl-cyanidin-3-O-(2″'galloyl)-β-d-galactopyranoside-4-vinyl-catechol-3″-O-β-d-glucopyranoside, respectively. Additionally, two related anthocyanin compounds, cyanidin-3-O-(2″galloyl)-β-d-galactopyranoside and 7-O-methyl-cyanidin-3-O-β-d-galactopyranoside were also recovered, with NMR spectroscopic values closely matching previous reports from other plant species. The prevalence of 7-O-methyl anthocyanins and their galloylated derivatives in sumac is highly unusual, and warrants special attention. Additionally, the in planta occurrence of two 7-O-methyl-pyranoanothocyanin-vinyl-catechol aglycones, Sumadin A and Sumadin B, and their derivatives is noted. To our knowledge, E-ring glycosylated vinyl-catechol pyranoanthocyanins were previously unknown.
authors.affiliation: Crops and Livestock Research Centre, Agriculture and Agri-Food Canada, 550 University Avenue, Charlottetown, PE C1A 4P3, Canada.
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Kirby
authors.forename: Tao
authors.initials: T
authors.lastname: Wu
authors.forename: Rong
authors.initials: R
authors.lastname: Tsao
authors.forename: Jason L
authors.initials: JL
authors.lastname: McCallum
mesh_terms: D000872:Anthocyanins / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005638:Fruit / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D015394:Molecular Structure; D011714:Pyrans / Q000737:chemistry; D029045:Rhus / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D000872:Anthocyanins; D011714:Pyrans
keywords: Anacardiaceae; Anthocyanin; Pyranoanthocyanin; Rhus typhina; Staghorn sumac; Sumadin; Vinyl-catechol