![]() In some samples, especially from Vejle river, the rise in concentration of target compounds were associated with increase in the rain intensity and elevated water table in the river. Individual compound concentrations were up to several hundred ng/L with the neurotoxic alkaloid coniine from poison hemlock and the flavonoid daidzein reaching maximum concentrations of about 400 and 282 ng/L, respectively. The most prominent compound class was the group of alkaloids with 41% of the detected targets, many of them detected in more than 80% of the samples. In total, 27 targets belonging to different compound classes such as alkaloids, coumarins and flavonoids were detected, among them 12 compounds, which have not been reported in surface waters before. The samples were collected during rain events from three Danish rivers from an area covered by grassland, forest and agricultural crops. ![]() To this end, we performed target screening on 160 toxic secondary plant metabolites (PSMs), prioritized in silico for their likelihood of occurrence, persistence, toxicity and mobility in river waters, using liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS). Since previous studies suggest that natural compounds might contribute to mixture risks in aquatic ecosystems and for drinking water production, there is a need to increase empirical evidence on the occurrence of these compounds in aquatic systems. So far, unlike anthropogenic pollutants, naturally occurring compounds are not included in environmental monitoring programs due to limited knowledge on their occurrence and effects in the environment. Thus, comfrey root is an important source of phenolic compounds endowed with antioxidant activity which may contribute to the overall bioactivity of Symphytum preparations.Ī large number of chemicals are constantly introduced to surface water from anthropogenic and natural sources. Comfrey root extract exhibited significant antioxidant activities when compared to known antioxidants. Lastly, the antioxidant activity was determined using four assays: DPPH and ABTS radicals scavenging assays, reducing power assay and 15-lipoxygenase inhibition assay. In addition, pyrrolizidine alkaloids were evaluated by HPLC-QQQ-MS/MS and acetylintermedine, acetyllycopsamine and their N-oxides were determined as major pyrrolizidine alkaloids in the comfrey root sample. Moreover, trimers and tetramers of caffeic acid (isomers of salvianolic acid A, B and C) were identified and quantified for the first time in comfrey root. Rosmarinic acid was identified as main phenolic constituent (7.55 mg/g extract). The phenolic profile of comfrey root sample was characterized by HPLC-DAD-QTOF-MS/MS. Therefore, we applied different approaches to further characterize a comfrey root extract (65% ethanol). Up to date, key activity-determining constituents of comfrey root extracts have not been completely elucidated. Hence, these results provided comprehensive approaches for treating comfrey root enriched in different phytochemicals, thereby enhancing its bioaccessibility.Ĭomfrey root preparations are used for the external treatment of joint distortions and myalgia, due to its analgesic and anti-inflammatory properties. The main compositional differences between extracts obtained by different extraction techniques were assigned to the solvent type. SFE using 15% EtOH as a cosolvent at 150 bar produced the best recoveries of a significant number of fatty acids. The use of SFE and 100% acetone for 30 min enabled good recoveries of nonpolar compounds. Greater numbers of phenolics were best extracted by PLE using 85% EtOH at 63 ![]() ![]() PLE and maceration, using alcohol-based solvents (aqueous methanol or ethanol), were shown to be more efficient in the recovery of more polar compounds. officinale root was investigated for all applied techniques. The influence of different extraction parameters on phytochemical profiles of S. Phytochemical composition was assessed by high-performance liquid chromatography coupled with electrospray time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS/MS) identifying 39 compounds reported for the first time in comfrey root, mainly phenolic acids and fatty acids. Chemical profiles of extracts obtained by supercritical fluid (SFE), pressurized liquid (PLE), and conventional solid/liquid extraction were compared and discussed. In this work a comparative study on phytochemical profiles of comfrey root extracts obtained by different extraction approaches has been carried out.
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