title: Quantitative analysis of polymeric proanthocyanidins in birch leaves with normal-phase HPLC.
abstract: The proanthocyanidin composition and content in the leaves of nine birch species (Betula albosinensis, B. ermanii B. maximowicziana, B. nana, B. papyrifera, B. pendula, B. platyphylla, B. pubescens, and B. pubescens ssp. czerepanovii) were studied with different methods including colorimetric assay, HPLC coupled with PAD or ESI/MS and NMR. Total proanthocyanidin content was determined using the acid butanol assay. A normal phase-HPLC method was applied for the analysis of polymeric proanthocyanidins. The content of polymeric proanthocyanidins was estimated from a late eluting peak in the chromatogram. With this HPLC method, quantitative analysis of polymeric proanthocyanidins could be performed directly from leaf extracts: no additional purification or preparation steps were required. It was shown that birch leaves contained mainly polymeric proanthocyanidins with a degree of polymerisation greater than 10. Total proanthocyanidin content (expressed as dry weight) was found to vary from 44mg/g (B. papyrifera) to 145mg/g (B. nana), and polymeric proanthocyanidin content from 39mg/g (B. pendula) to 119 mg/g (B. nana).
authors.affiliation: Laboratory of Organic Chemistry and Chemical Biology, Department of Chemistry, University of Turku, FIN-20014 Turku, Finland. maarit.karonen@utu.fi
authors.forename: Maarit
authors.initials: M
authors.lastname: Karonen
authors.forename: Vladimir
authors.initials: V
authors.lastname: Ossipov
authors.forename: Jari
authors.initials: J
authors.lastname: Sinkkonen
authors.forename: Jyrki
authors.initials: J
authors.lastname: Loponen
authors.forename: Erkki
authors.initials: E
authors.lastname: Haukioja
authors.forename: Kalevi
authors.initials: K
authors.lastname: Pihlaja
mesh_terms: D029662:Betula / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D019906:Nuclear Magnetic Resonance, Biomolecular; D018515:Plant Leaves / Q000737:chemistry; D044945:Proanthocyanidins / Q000032:analysis* / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet
chemical_list: D044945:Proanthocyanidins