Abstract
Phyllobilins (PBs) are the main products of chlorophyll degradation in plants and algae via the pheophorbide-a oxygenase (PaO)/PB pathway, leading to nonfluorescent chlorophyll catabolites (NCCs), yellow chlorophyll catabolites (YCCs) and the nonfluorescent dioxobilane type NCCs (DNCCs). Pharmacological activities have been described for PBs, including anti-inflammatory and anti-oxidative properties. The aim of this study was to analyze PBs in methanolic extracts of leaves in two physiological stages (green and senescent) and in tea preparations of the following plants: Urtica dioica (common nettle), Echinacea purpurea (purple coneflower) and Fagopyrum esculentum (buckwheat) using liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HR-Q-TOF-MS). A fullscan mode was applied for semi-quantification of the two PBs NCC-806 and YCC-804. In green and in senescent leaves NCC-806 concentrations were higher than YCC-804, except in coneflower species. In all three species the concentrations of NCC-806 and YCC-804 increased significantly from green to senescence, whereas highest concentrations were detected in senescent nettle leaves. The stability of PBs and their transition from drug material into the infusion was confirmed. The highest PBs concentration in tea infusions of green leaves were found in nettle species. In conclusion, this study showed that a remarkable content of PBs are present in herbal species, which should be further investigated for their potential in food supplements or pharmaceutical applications.