Large scale extraction of pyrrolizidine alkaloids from tansy ragwort (Senecio jacobaea)

A new technique of large-scale pyrrolizidine alkaloid (PA) extraction was developed in response to toxicity studies on food animals. Results of toxicity experiments on cattle vary from those on rodents (2); therefore, dose/response studies need to be germaine to the appropriate species. This new technique for extraction utilizes protonation of the ring nitrogen and partition of solvent to preferentially extract the alkaloid. The primary equipment used in the system we developed includes a large stainless-steel extraction/separation tank, holding tanks, and a 100-liter vacuum distillation system. From 23 kg of plant material of Senecio jacobaea , our system was able to produce 8-10 g of alkaloid per run, compared to the 3 g which we achieved using other extraction methods (2,4). Additional advantages of our system include a lower labor cost and the ability to recycle the organic solvent.