[Quantitative analysis of active substances in St. John's wort (Hypericum perforatum L.) by the high performance liquid chromatography method].

The flavonoids (rutin, quercetin, and isoquercetin) and hypericin are the main active substances of St. John's wort (Hypericum perforatum). They support regeneration of human body cells, provide disinfection, and act as antidepressant, antiviral, and anti-inflammation tools. Such large spectrum of the applicable functions depends on the quantity of each substance. The objective of this paper is to determine the regularities of the quantitative variation of rutin, quercetin, isoquercetin and hypericin in flowers and leaves of St. John's wort in different habitats and different plant development phases. Plant material for the quantitative analysis was collected in 1998-1999. The high performance liquid chromatography (HPLC) was applied for the quantitative analysis of the active substances in St. John's wort. The flavonoids (rutin, quercetin, and isoquercetin) were identified under the UV waves of 254 nm, and hypericin - under the waves of 590 nm. Larger quantities of rutin were found in leaves, while those of quercetin, isoquercetin and hypericin - in flowers of St. John's wort. The highest accumulation of active substances was observed during the development of flowering buds and in flowering time. The quantitative variation of active substances in different habitats allows the selection of the best plant samples for their cultivation and conservation in field collections.