Composition and stability over time of “buds 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 poorly studied to date. Our research was focused to have a phytochemical characterization in terms of secondary metabolites of black currant, dog rose and silver linden buds extracts and to evaluate the changes of selected chemical markers over time. 16 different preparations have been analyzed by the use of HPLC-DAD-MS. In black currant samples were identified flavonols in particular quercetin derivatives (6.72-30.9 mg/L) and hydroxycinnamic acids in particular p-coumaric acid derivatives (4.06-39.18 mg/L). For dog rose samples, among flavonols (glycosides of quercetin an kaempferol) and hydroxycinnamic acids, gallic and ellagic tannins were identified as main components (up to 1,7 g/L). The Tilia tomentosa extracts showed flavonols (quercetin, kaempferol, apigenin derivatives) as the main group with the exception of a single commercial extract with hydroxycinnamic acids as more abundant metabolites. In this work, without applying accelerated ageing protocols, the stability over time of 9 liquid preparations was evaluated up to 10 months, demonstrating negligible variations.