Steriodal alkaloid glycosides in Easter Lilies

Isolation and purification of steroidal alkaloid glycosides from Easter lily (Lilium longiflorum), and their effects on feline proximal tubuli (Master’s project)

Background and state of the art
Cats are very sensitive to poisoning by plants of the genus Lilium. Easter lilies are one of the species that have been documented to cause toxicosis in cats. Both leaves and flowers are reportedly toxic. Ingestion of 1 or 2 leaves or 1 whole flower has caused toxicosis in cats. The kidney is the primary target organ – cats die of acute renal failure 3-5 days after exposure. The mortality rate from Easter lily poisoning is reported to be as high as 50-100%. Though the morphologic effects of Easter lily poisoning are well described in the literature, the toxic principal compound(s) responsible for the intoxication are not yet identified.

In a recent pilot study, performed at the Chemistry and Toxicology Section at the Norwegian Veterinary Institute, feline proximal tubuli (a type of kidney cell) were exposed to extracts from the plant as well as fractions from chromatographic separation of the extracts. The bioassay-guided fractionation traced the observed cytotoxicity primarily to a subfraction containing a cluster of at least five compounds that were tentatively identified as glycosides of steroidal alkaloids.

In the project, the student will develop a method for the semi-preparative isolation and purification of the putative steroidal alkaloid glycosides. In parallel, the student will use mass spectrometric techniques (MSn fragmentation using ion trap MS and high-resolution MS using Q-TOF-MS) for the characterisation of the compounds. Finally, a dose-response relationship will be established for the cytotoxicity of the isolated compounds in a bioassay using feline proximal tubuli.