Qualitative and Quantitative Determination of Hydrolysable Tannins and Other Polyphenols in Herbal Products from Meadowsweet and Dog Rose

Introduction - Meadowsweet and dog rose are used as herbal medicines and foodstuffs. Their biological and pharmacological properties are mainly attributed to vitamins, flavonoids and tannins known to be effective antioxidants. Objective - To evaluate the distribution of hydrolysable tannins and other polyphenols in commercially available products of Filipendula ulmaria and Rosa canina. Methodology - In order to evaluate the distribution of polyphenols, the isolation and structure elucidation of six ellagitannins (tellimagrandins I and II, rugosins A, B, D and E) along with other well-known compounds was performed. Further high-performance chromatographic methods (HPLC, HPTLC) were developed for qualitative and quantitative studies of phenolic acids, flavonoids and tannins in meadowsweet flowers and dog rose fruits. The analysis of linearity, limits of detection and quantification, precision and accuracy showed that the HPLC assay was sufficiently precise for content evaluation. Selection of a suitable solvent and optimisation of the sample extraction procedure were also carried out. Results - Amounts of more than 20 polyphenols were estimated in the studied pharmaceuticals (27 products of meadowsweet and 10 products of dog rose) using a Chromolith Performance RP-18e column and UV detection. Methyl gallate 3-O-beta-glucoside was identified for the first time in dog rose, while rugosins A, B and E are new meadowsweet constituents. Conclusion - The results showed that meadowsweet flowers and rose hips with seeds yielded 55.53-124.8 and 0.43-1.26 mg/g of ellagitannins, respectively. The sum of detected polyphenols was 83.88-165.68 mg/g for Filipenclulae ulmariae flos and 1.21-2.66 mg/g for Rosae pseudo-fructus cum fructibus. Copyright (C) 2009 John Wiley & Sons, Ltd.