Pyrrollizidine alkaloids

Pyrrollizidine alkaloids are plant substances that are formed by numerous plants to protect them from predators.
Biochemically, pyrrollizidine alkaloids belong to the ester alkaloids. Pyrrollizidine is the basic structure that is esterified with mono- or dibasic terpenoid acids (e.g. angelic acid or nectic acids).

Of course in Senecio species but also in other Asteraceae.
Pyrollizidine alkaloids with an allyl ester structure form dehydroderivatives in the liver which are toxic to liver cells and also have a carcinogenic potency.
The therapeutic value of pyrollizidine alkaloid-containing drugs is disputed. Pyrollizidine alkaloids can enter the food chain (e.g. via herbal teas or via pyrollizidine alkaloid contaminated pollen in bee honey)
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1. Cramer L et al (2013) Pyrrolizidine alkaloids in the food chain: development, validation, and application of a new HPLC-ESI-MS/MS sum parameter method. J Agric Food Chem 61:11382-1191.
2. Gao H et al (2015) Blood pyrrole protein adducts as a diagnostic and prognostic index in pyrrolizidine alkaloid-hepatic sinusoidal obstruction syndrome. Drug of Devel Ther 9:4861-4868.
3. Mudge EM et al(2015) Quantification of pyrrolizidine alkaloids in North American plants and honey by LC-MS: single laboratory validation. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 32:2068-2074.