Qualitative and quantitative analyses of bioactive compounds from ex vitro Chamaenerion angustifolium (L.) (Epilobium augustifolium) herb in different harvest times

The rosebay willowherb (Chamaenerion angustifolium (L.) Scop. syn. Epilobium angustifolium L.) from Onagraceae family is a valuable medicinal plant. The aim of our research was to measure the effect of different harvest times on the profile and concentration of oenothein B, polyphenols, flavonoids and sterols after ex vitro Chamaenerion angustifolium multiplication. For this purpose, we compared phytochemical properties of the herb in two ex vitro lines: German (DE) and Polish (PL), collected in two different harvest times: during and after the flowering period-in June and in September respectively. The qualitative and quantitative analyses were conducted using advanced LC-MS systems, including: HPLC-DAD-MSn, UPLC-PDA-MS/MS, HPLC-DAD, UPLC-MS/MS and the spectrophotometric methods. In the course of the qualitative analysis of herb samples, 45 phenolic metabolites were identified, from which gallic acid, oenothein B and quercetin 3-O-arabinoside were the principal compounds. In both lines, the quantitative determination with the use of two chromatographic methods showed the highest concentration of oenothein B, beta - sitosterol and ellagic acid, whereas in the analysis with the spectrophotometric method, it was the total polyphenols content that predominated (expressed as gallic acid). In most cases, the flowering period was a better source of active compounds. The chemical characteristics of ex vitro raw material is similar to the field crop plants profile, confirming the positive application of the ex vitro cultivation method.