26131-12-4Relevant academic research and scientific papers
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.
Enantiospecific synthesis of (+)- and (-)-trachelanthic acids via asymmetric dihydroxylation and their conversion to the pyrrolizidine alkaloids indicine and intermedine
Nambu, Mitch,White, James D.
, p. 1619 - 1620 (2007/10/03)
Asymmetric dihydroxylation of (E)-ethyl 2-isopropylbut-2-enoate with AD-mix-a and AD-mix-P, followed by saponification, gives (-)- and (+)-trachelanthic acids, respectively, which are each coupled via their acetonides with (+)-retronecine to yield the pyrrolizidine alkaloids indicine and intermedine.
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).
THE TOTAL SYNTHESES OF (-)-INDICINE N-OXIDE AND INTERMEDINE N-OXIDE
Nishimura, Yoshio,Kondo, Shinichi,Umezawa, Hamao
, p. 4323 - 4326 (2007/10/02)
The total syntheses of (-)-indicine N-oxide, the enantiomer of natural indicine N-oxide and intermedine N-oxide have been achieved.
Synthesis of pyrrolizidine alkaloids indicine, intermedine, lycopsamine, and analogues and their N-oxides. Potential antitumor agents
Zalkow,Glinski,Gelbaum,Fleischmann,McGowan,Gordon
, p. 687 - 694 (2007/10/02)
(-)- and (+)-trachelanthic and (-)- and (+)-viridifloric acids were synthesized and their isopropylidene derivatives were regiospecifically coupled, at C-9, with (-)-retronecine (2) obtained by hydrolysis of monocrotaline (1), isolated from Crotalaria spectabilis. Hydrolysis, followed by oxidation, led to the N-oxides of indicine (7), intermedine (13), lycopsamine (15), and the new nonnatural product 16, respectively. Each of these analogues was screened in the P388 lymphocytic leukemia system at the same time as indicine N-oxide, and the results were compared. Other related analogues were prepared and similarly screened and the results compared with those from indicine N-oxide.
Nonstabilized Imidate Ylides by the Desilylation Method: A Route to the Pyrrolizidine Alkaloids Retronecine and Indicine
Vedejs, Edwin,Larsen, Scott,West, Frederick G.
, p. 2170 - 2174 (2007/10/02)
Imidate ylides, members of the azomethine ylide family, are generated by desilylation of N- imidate salts with CsF.This technique is used to prepare monoprotected retronecine 16 starting from butyrolactam.The route is improved over
