Improved field tests for toxic pyrrolizidine alkaloids.
Two new qualitative field tests for unsaturated pyrrolizidine alkaloids (PAs) and their N-oxides are described. The tests are sensitive and able to detect all the potentially hepatotoxic PAs, except otonecine-based alkaloids. They do not respond to most saturated PAs. The first test, primarily for PA N-oxides, is particularly easy to perform in the field and can be extended to detect basic PAs with lower sensitivity. The second test is an improvement on an earlier N-oxide test and now detects both N-oxides and basic PAs. Practical details are given for testing both fresh and dried leaves, roots, woody material, seeds, and plant-based foodstuffs such as flour. The sensitivity of the tests has been assessed using pure PAs and N-oxides, and a range of fresh and dried plant samples has been tested. A simple test for PA N-oxides only has proved adequate to identify the majority of plants containing 0.005% or more of PAs using samples of 0.1-0.5 g. High levels of PA N-oxides were found to persist for more than 20 years in dried plant materials.
Mattocks
A R
AR
Toxicology Unit, Medical Research Council Laboratories, Carshalton, Surrey, United Kingdom.
Jukes
R
R
D007202:Indicators and Reagents; D008970:Molecular Weight; D010944:Plants / Q000032:analysis; D011763:Pyrrolizidine Alkaloids / Q000032:analysis* / Q000633:toxicity
D007202:Indicators and Reagents; D011763:Pyrrolizidine Alkaloids