Efficient Extraction of Pyrrolizidine Alkaloids from Plants by Pressurised Liquid Extraction – A Preliminary Study

Abstract

Pyrrolizidine alkaloids and their corresponding pyrrolizidine alkaloid-N-oxides are secondary plant constituents that became the subject of public concern due to their hepatotoxic, pneumotoxic, genotoxic, and cytotoxic effects. In contrast to the well-established analytical separation and detection methods, only a few studies have investigated the extraction of pyrrolizidine alkaloids/pyrrolizidine alkaloid-N-oxides from plant material. In this study, we have applied pressurized liquid extraction with the aim of evaluating the effect of various parameters on the recovery of pyrrolizidine alkaloids. The nature of the modifier (various acids, NH3) added to the aqueous extraction solvent, its concentration (1 or 5%), and the temperature (50 – 125 °C) were systematically varied. To analyse a wide range of structurally different pyrrolizidine alkaloids, Jacobaea vulgaris (syn. Senecio jacobaea), Tussilago farfara, and Symphytum officinale were included. Pyrrolizidine alkaloids were quantified by HPLC-MS/MS and the results obtained by pressurised liquid extraction were compared with the amount of pyrrolizidine alkaloids determined by an official reference method. Using this approach, increased rates of recovery were obtained for J. vulgaris (up to 174.4%), T. farfara (up to 156.5%), and S. officinale (up to 288.7%). Hence, pressurised liquid extraction was found to be a promising strategy for the complete and automated extraction of pyrrolizidine alkaloids, which could advantageously replace other time- and solvent-consuming extraction methods.

Globoidnan A, rabdosiin and globoidnan B as new phenolic markers in European‐sourced comfrey (Symphytum officinale L.) root samples

“…7 The levels of intermedine and lycopsamine in a German root specimen varied between 0.218 and 0.483 mg/g and 0.096 and 0.249 mg/g, respectively, depending on the extraction temperature (50-125 C) and additive (phosphoric acid, ammonia, sulfuric acid, acetic acid, formic acid) included in the aqueous extraction solvent. 33 The same two PA markers were quantified by Avula et al, 24 with their levels up to maximum 0.015 mg/g. Liu et al 26 showed that lycopsamine levels in a Colombian comfrey root specimen were between 0.010 and 0.014 mg/g in a pressurized hot water extract and between 0.029 and 0.032 mg/g in a methanol/water (1/1) extract obtained under reflux.…”

Antioxidant Capacity and Protective Effect of Aqueous and Hydroalcoholic Extracts of Senecio rhizomatus Rusby "Llancahuasi" on Erythrocytes Subjected to Oxidative Stress

“…35 Pyrrolizidine alkaloids have also been identified in Senecio jacobaea and Senecio Brasiliensis species, where their anti-inflammatory, immunomodulatory and cytotoxic effect have been demonstrated. 36,37 In the case of Senecio nulans, Senecio chiquianensis, Senecio hyoseridifolius, Senecio tphrosiodies, secondary metabolites have been identified in ethanolic extracts and essential oils (terpenes, phenolic compounds, flavonoids, pyrrolizidinic alkaloids, lactones), showing good antibacterial activity against staphylococcus aureus bacteria. [38][39][40][41] It is necessary to explore the characterization of secondary metabolites of Senecio rhizomatus in order to guide in vitro and in vivo pharmacological research that would favor the preservation and rational use of the species.…”

A review of the ethnobotanical value, phytochemistry, pharmacology, toxicity and quality control of Tussilago farfara L. (coltsfoot)

“…As well as, Nedelcheva et al (2015) also identified two PAs named, seneciphylline (129) and integerrimine (128) by gas chromatography and mass spectrometry analysis ( Nedelcheva et al , 2015 ). Senecivernine (130) was quantified by HPLC-MS/MS and pressurised liquid extraction ( Kopp et al , 2020 ). The authors concluded that this approach can be used to the complete and automated extraction of pyrrolizidine alkaloids ( Kopp et al , 2020 ).…”

“…Senecivernine (130) was quantified by HPLC-MS/MS and pressurised liquid extraction ( Kopp et al , 2020 ). The authors concluded that this approach can be used to the complete and automated extraction of pyrrolizidine alkaloids ( Kopp et al , 2020 ). Tussilagine (121), another PAs, has been isolated and identified in flowers of coltsfoot by HILIC/ESI-QTOF-MS and HPTLC ( Smyrska-Wieleba et al , 2017 ).…”

“…For an on-line pre-concentration method, which is feasible for the analysis of pyrrolizidine alkaloids in coltsfoot with good recoveries ( Cao et al , 2016 ). The result from pressurised liquid extraction increased rates of recovery were obtained for coltsfoot up to 156.5% ( Kopp et al , 2020 ).…”