A sensitive analytical method for pyrrolizidine alkaloids. The mass spectra of retronecine derivatives

Abstract

The pyrrolizidine alkaloids in Senecio jacobaea can be hydrolyzed to the common base, retronecine, and derivatized to form the bistrifluoroacetate, bisheptafluorobutyrate, diacetate and bistrimethylsilyl ether. The analysis of the fluorinated compounds by electron capture provides sensitivity for detection of these alkaloids. The bond weakening effect in the ion formed on electron impact, between the allylic carbon and alkyl ester oxygen due to the electron withdrawing fluorinated groups of the ester, changes the driving force for fragmentation from the nitrogen alpha-cleavage reaction to a charge site migration. This yields alkyl-oxygen bond cleavage and formation of a stabilized allylic cation which is the base peak.

The History of the Glycosidase Inhibiting Hyacinthacine C-type Alkaloids: From Discovery to Synthesis.

“…However, it is more alarming that many cases of liver disease and cancer in humans have been the direct result of pyrrolizidine alkaloid consumption [ 3 - 6 ]. This widespread occurrence is not surprising since there have been recorded findings of pyrrolizidine alkaloids detected in wheat flour, honey and also cow’s milk [ 7 - 9 ]. At least from an economic point of view, it remains important that improved methods of detection, chromatographic separation and chiefly, natural product characterization are continually explored.…”

“…[3][4][5][6] This wide spread occurrence is not surprising since there have been recorded findings of pyrrolizidine alkaloids detected in wheat flour, honey and also cow's milk. [7][8][9] At least from an economic point of view, it remains important that improved methods of detection, chromatographic separation and chiefly, natural product characterization are continually explored. In the early 1980s, pyrrolizidine alkaloids were deemed pernicious upon ingestion and were consequently flagged as a worldwide health concern.…”