Phenolic composition of "bud extracts" of Ribes nigrum L., Rosa canina L. and Tilia tomentosa M.

Liquid preparations such as tinctures and "bud extracts" are typical products widely used in European countries but which have been poorly studied to date. Our research was focused on obtaining a phytochemical characterization of secondary metabolites of black currant, dog rose and silver linden bud extracts and evaluating the changes of selected chemical markers over time. 16 different preparations have been analyzed by the use of HPLC-DAD-MS. Several flavonols were identified in black currant samples including quercetin derivatives (6.7-30.4mg/L). Also hydroxycinnamic acids, mainly p-coumaric acid derivatives (4.1-38.9mg/L) were identified. Flavonols such as glycosides of quercetin and kaempferol, hydroxycinnamic acids, and ellagitannins were detected in dog rose samples, with gallotannins being the main components (up to 1.7g/L). The Tilia tomentosa extracts contained flavonols (quercetin, kaempferol, apigenin derivatives) as principal components with the exception of a single commercial extract with hydroxycinnamic acids as the most abundant metabolites. In this study, without applying accelerated ageing protocols, the stability over time of these liquid preparations was evaluated for up to 10 months and demonstrated negligible variations.