26131-12-4Relevant articles and documents
An Efficient Enantioselective Synthesis of Indicine N-Oxide, an Antitumor Pyrrolizidine Alkaloid
Ogawa, Takeshi,Niwa, Haruki,Yamada, Kiyoyuki
, p. 1571 - 1578 (1993)
Indicine N-oxide (1), a pyrrolizidine alkaloid potentially useful for an anticancer drug was synthesized in the natural form through regioselective coupling of (+)-retronecine (2) and the protected necic acids 16a and 16b, the latter being efficiently prepared from the optically pure lactone 5.
Ideamine N-Oxides: Pyrrolizidine Alkaloids Sequestered by the Danaine Butterfly, Idea leuconoe
Nishida, Ritsuo,Kim, Chul-Sa,Fukami, Hiroshi,Irie, Ryozo
, p. 1787 - 1792 (2007/10/02)
Two new pyrrolizidine alkaloids, ideamines A and B, together with other analogs (lycopsamine and parsonsine) were isolated in the N-oxide forms from adult bodies of the Apocynaceae-feeding danaine butterfly, Idea leuconoe.Ideamine A was characterized as a homolog of lycopsamine, in which the viridifloric acid moiety was replaced by a 2-ethyl-2,3-dihydroxybutanoic moiety.Likewise, ideamine B was identified as a nor-derivative of parsonsine, in which the trachelanthic acid moiety was replaced by a 2-ethyl-2,3-dihydroxybutanoic moiety diastereomeric to the necic acid from ideamine A.
Pyrrolizidine Alkaloid Biosynthesis. Synthesis of 3H-Labelled Trachelanthamidine and Isoretronecanol and their Incorporation into Three Pyrrolizidine Bases (Necines)
Kunec, Ellen K.,Robins, David J.
, p. 1437 - 1441 (2007/10/02)
(+/-)-Isoretronecanol (22) and (+/-)-trachelanthamidine (24) were prepared by 1,3-dipolar cycloaddition of N-formylproline with ethyl propiolate followed by reduction steps.These 3H-labelled 1-hydroxymethylpyrrolizidines together with putrescine were fed to Senecio isatideus which produces retrorsine (1); S. pleistocephalus which yields rosmarinine (8); and Cynoglossum officinale which affords echinatine (5).The double labelling experiments demonstrated that isoretronecanol is incorporated much more efficiently into rosmarinine than into retrorsine or echinatine, whereas trachelanthamidine is a much more efficient precursor for retrorsine and echinatine.Base hydrolysis of retrorsine and echinatine labelled with trachelanthamidine and of rosmarinine labelled with isoretronecanol established that most of the 3H-label was in the base portions, retronecine (2), heliotridine (6), and rosmarinecine (9), respectively.Further degradation of retronecine and rosmarinecine showed that most of the radioactivity was confined to the β-alanine (4) portion.The biosynthetic pathways to isoretronecanol and trachelanthamidine apparently diverge prior to the formation of these 1-hydroxymethylpyrrolizidines, probably during the cyclisation of an immonium ion (14) to form the 1-formylpyrrolizidines (15) and (17).
