Senecio othonnae

Extraction of Senecio othonnae gave otosenine in 0.07% 3neld. The presence of one hydroxyl and one iV-methyl group was indicated by analysis. 

In an earlier study, the presence of otosenine (32), onetine (33), and sene-ciphylline (36) was established in Senecio othonnae Bieb. Russian workers have now isolated doronine (34), otosenine (32), and floridanine (35) from the same species. Curiously, these are exactly the same constituents reported by the same workers from Doronicum macrophyllum (see last year s Report). 

Pterophorine and inaequidenine, two other dihydropyrrolizinone alkaloids, were previously isolated from Senecio inaequidens DC. (cf. Vol. 8, pp. 54-56). Senecionine and retrorsine have now also been shown to be present in this species.31,32 7-Angelylheliotridine (43) has been isolated from S. ovirensis ssp. gaudinii.32,33 The cause of poisoning in dairy cattle in Switzerland was found to be S. alpinus.34 Nine known pyrrolizidine alkaloids were isolated from this species, and the major constituent was seneciphylline. Otosenine, floridanine, and doronine are present in 5. othonnae.35 The extraction of seneciphylline and platyphylline from S. platyphylloides has been studied by a variety of methods.36... 

Compounds (489)—(502) and (503)—(505) represent new eremophilane metabolites isolated from various Senecio and Lopholaena species. Related papers by the same research group describe the structural elucidation of 55 new eremophilanes found in 27 Europys species " and 23 similar compounds isolated from Othonna species. ... 

---