Phytochemical characterisation of pharmaceutical extracts from <i>Equisetum arvense</i> L. by HPLC-DAD-MSⁿ and GC-MS.

<i>Equisetum arvense</i> L., commonly known as horsetail, is the most prominent <i>Equisetum</i> species and a widely used medicinal plant in traditional and herbal medicine. This study presents a comprehensive phytochemical characterisation of various pharmaceutical extracts prepared from field horsetail according to a national pharmacopoeia, including aqueous fermented extracts, oil-based extracts and hydroalcoholic extracts. Polar constituents were analysed using HPLC-DAD-ESI-MS n. GC-MS analyses following silylation were performed to elucidate low-molecular-weight compounds. The results revealed different phytochemical compositions of the <i>E. arvense</i> L. extracts, with distinct profiles of compounds including hydroxycinnamic acids and flavonoids. The results of the GC-MS investigations indicated the presence of an even broader variety of compounds, comprising benzoic acids, fatty acids, sugars, and phytosterols. Additionally, chlorophyll and carotenoid contents were quantified in the oil-based extracts by UV-VIS spectroscopy. This study underlines the significant impact of the respective extraction parameters on the phytochemical profile of the corresponding pharmaceutical extracts and highlights the rich history and continuing importance of this medicinal plant in traditional and complementary medicine.