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.

Key words

pyrrolizidine alkaloids - Symphytum officinale - Tussilago farfara - Senecio jacobaea - Jacobaea vulgaris - pressurised liquid extraction - Boraginaceae - Asteraceae

• References

• 1 Roeder E. Medicinal plants in Europe containing pyrrolizidine alkaloids. Pharmazie 1995; 50: 83-98
• 2 Analytik und Toxizität von Pyrrolizidinalkaloiden sowie eine Einschätzung des gesundheitlichen Risikos durch deren Vorkommen in Honig. Available at: https://www.bfr.bund.de/cm/343/analytik-und-toxizitaet-von-pyrrolizidinalkaloiden.pdf Accessed January 7, 2019
• 3 Colegate SM, Gardner DR, Betz JM, Fischer OW, Liede-Schumann S, Boppré M. Pro-toxic 1,2-dehydropyrrolizidine alkaloid esters, including unprecedented 10-membered macrocyclic diesters, in the medicinally-used Alafia cf. caudata and Amphineurion marginatum (Apocynaceae: Apocynoideae: Nerieae and Apocyneae). Phytochem Anal 2016; 27: 257-276
• 4 Hartmann T. Chemical ecology of pyrrolizidine alkaloids. Planta 1999; 207: 483-495
• 5 Mattocks AR. Toxicity of pyrrolizidine alkaloids. Nature 1968; 217: 723-728
• 6 Bush LP, Fannin FF, Siegel MR, Dahlman DL, Burton HR. Chemistry, occurrence and biological effects of saturated pyrrolizidine alkaloids associated with endophyte-grass interactions. Agric Ecosyst Environ 1993; 44: 81-102
• 7 Bestimmung von Pyrrolizidinalkaloiden (PA) in Pflanzenmaterial mittels SPE-LC-MS/MS. Available at: https://www.bfr.bund.de/cm/343/bestimmung-von-pyrrolizidinalkaloiden.pdf Accessed February 27, 2019
• 8 Roeder E, Breitmaier E, Birecka H, Frohlicht MW, Badzies-Crombach A. Pyrrolizidine alkaloids of Heliotropium spathulatum . Phytochemistry 1991; 30: 1703-1706
• 9 Kim NC, Oberlies NH, Brine DR, Handy RW, Wani MC, Wall ME. Isolation of symlandine from the roots of common comfrey (Symphytum officinale) using countercurrent chromatography. J Nat Prod 2001; 64: 251-253
• 10 Segall HJ. Preparative isolation of pyrrolizidine alkaloids derived from Senecio vulgaris . J Liq Chromatogr 1979; 2: 1319-1323
• 11 Wiedenfeld H. Zur gaschromatographischen Bestimmung der Pyrrolizidinalkaloide aus einigen Senecioarten. Planta Med 1981; 41: 124-128
• 12 Bicchi C, Rubiolo P, Frattini C, Sandra P, David F. Off-line supercritical fluid extraction and capillary gas chromatography of pyrrolizidine alkaloids in Senecio species. J Nat Prod 1991; 54: 941-945
• 13 Avula B, Sagi S, Wang YH, Zweigenbaum J, Wang M, Khan IA. Corrigendum to “Characterization and screening of pyrrolizidine alkaloids and N-oxides from botanicals and dietary supplements using UHPLC-high resolution mass spectrometry”. Food Chem 2015; 178: 136–148. Food Chem 2018; 248: 361-363
• 14 Mroczek T, Widelski J, Gowniak K. Optimization of extraction of pyrrolizidine alkaloids from plant material. Chem Anal (Warsaw) 2006; 51: 567-580
• 15 Cooper RA, Bowers RJ, Beckham CJ, Huxtable RJ. Preparative separation of pyrrolizidine alkaloids by high-speed counter-current chromatography. J Chromatogr A 1996; 732: 43-50
• 16 Zalkow L, Asibal C, Glinski J. Macrocyclic pyrrolizidine alkaloids from Senecio anonymus. Separation of a complex alkaloid extract using droplet counter-current chromatography. J Nat Prod 1988; 51: 690-702
• 17 Schulz M, Meins J, Diemert S, Zagermann-Muncke P, Goebel R, Schrenk D, Schubert-Zsilavecz M, Abdel-Tawab M. Detection of pyrrolizidine alkaloids in German licensed herbal medicinal teas. Phytomedicine 2015; 22: 648-656
• 18 Lebada R, Schreier A, Scherz S, Resch C, Krenn L, Kopp B. Quantitative analysis of the pyrrolizidine alkaloids senkirkine and senecionine in Tussilago farfara L. by capillary electrophoresis. Phytochem Anal 2000; 11: 366-369