Senecio alkaloids occurrence

Koekemoer MJ, Warren FL. The senecio alkaloids. VIII. The occurrence and preparation of the N-oxides. An improved method of extraction of the senecio alkaloids. J Chem Soc 1951 47 66-8. 

This group of alkaloids is found in a wide range of families, centred around the Asteraceae, Boraginaceae and Fabaceae (Hartmann and Witte, 1995 Hartmann, 2007). PAs are metabolically activated in the liver of herbivores and can then alkylate DNA and proteins, leading to mutations and even cancer. The occurrence of PAs in many Senecio species accounts for the high toxicity of these plants. PAs function as defence compounds against many herbivores however, a number of specialized insects are known which store and utilize the dietary defence chemicals (for a review, see Wink, 1993 Hartmann and Witte, 1995). 

Deinzer ML, Thomson PA, Burgett DM, Isaacson DL. Pyrrohzidine alkaloids their occurrence in honey from tansy ragwort Senecio jacobaea L.). Science 1977 195(4277) 497-9. 

The already mentioned occurrence of certain alkaloids or alkaloid types in unrelated plants creates some problems for the chemotaxonomist (Matveyev, 1959 Sharapov, 1962). The pyrrolizidine alkaloids, for example, are produced by plants like Crotalaria in Fabaceae, Senecio in Com-positae, Lolium in Glumiflorae, Cynoglossum in Boraginaceae, and Secu-rinega in Euphorbiaceae (Crowley and Culvenor, 1962 Culvenor and Smith, 1967 Culvenor et aL, 1968a,b). The alkaloids derived from the pyridine nucleotide cycle are distributed in unrelated plants. The most common... 

Pyrrolizidine alkaloids are of common occurrence in plants, particularly in genera such as Senecio, Crotalaria, Symphytum, Echium and Heliotropium (1). Retronecine (1) and heliotridine (2), and numerous simple and complex esters of these and related alkaloids, are typical pyrrolizidines. Many pyrrolizidine alkaloids are potent hepatotoxins and carcinogens (2) thus, the pyrrolizidines have been widely studied and are considered to be among the most important groups of natural products in terms of their effects on human health and economic activities (3). 

Deinzer, M. L., P. A. Thomson, D. M. Burgett, and D. L. Isaacson Pyrrolizidine Alkaloids Their Occurrence in Honey from Tansy Ragwort (Senecio jacobaea L.). Science 195, 497 (1977). 

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