Ideamine N-Oxides:Pyrrolizidine Alkaloids Sequestered by the Danaine Butterfly, Idea leuconoe.

Abstract

Twonew pyrrolizidine alkaloids, ideamines A and B, together with other analogs (lycopsamine and parsonsine) were isolated in the TV-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 Bwas identified as a nor-derivative of parsonsine, in whichthe trachelanthic acid moiety was replaced by a 2-ethyl-2,3-dihydroxybutanoic moiety diastereomeric to the necic acid from ideamine A. Idea leuconoe Erichson is a large danaine butterfly whose larvae feed exclusively on the plant, Parsonsia laevigata Alston (Apocynaceae), in the Ryukyu Islands of Japan. Wehave isolated four pyrrolizidine alkaloids, both from the insect (adult bodies and eggs) and from the host plant, demonstrating the acquisition of the alkaloids directly from the larval host in this species.1} These alkaloids were found predominantly as TV-oxides in the insect tissues as well as in the plants. We report here the identification of the alkaloid components, which were isolated from the bodies of /. leuconoe, including two new analogs, ideamine A and B JV-oxides. Four alkaloid components (1-4) were isolated from an extract of laboratory-reared /. leuconoe adults by reverse-phase liquid chromatography.1} The molecular weights of compounds 1^1 were determined to be 301, 315, 441 and 455, respectively, from the

Chemical Ecology of Poisonous Butterflies: Model or Mimic? A Paradox of Sexual Dimorphisms in Müllerian Mimicry

“…Although the butterfly is not aposematic in coloration, compared to other toxic butterflies, it is highly conspicuous in the subtropical forests flying slowly and gracefully under the high predatory avian pressure such as the blue rock thrush, Monticola solitarius. The butterfly (originated in Okinawa) accumulates large quantities of PAs (ideamines A, B, and C, lycopsamine, parsonsine) as N-oxides from the host Parsonsia laevigata (Apocynaceae) during the larval stage (Nishida et al 1991;Kim et al 1994) (Fig. 11.3).…”

Chemical ecology of insect–plant interactions: ecological significance of plant secondary metabolites

“…3). 43,44) The alkaloids are considered to function as defensive substances against predators, and are used as pheromone precursor by males during courtship (see Section IV). Most other danaine species acquire PAs not from the hosts but as adults by foraging from PA-containing plants (see III-2).…”

“…42) Oriental fruit moth-herbal essence. Males of the oriental fruit moth, Grapholita molesta, emit a herbal scent, such as methyl epijasmonate (42) and ethyl (E)-cinnamate (43), from hairpencils to attract conspecific females after himself attracted to the female's vicinity by the female pheromone (e.g. (Z)-8-dodecenyl acetate).…”

“…66) Ester 42, known as the key ingredients in high-grade perfumes originally extracted from jasmine flowers, is a Note: Males of the giant danaine butterfly, I. leuconoe, biotransform defensive pyrrolizidine alkaloid, lycopsamine (39), to danaidone (40) and viridifloric β-1actone (41) and emit from the hairpencil organ as sex pheromone. A female oriental fruit moth, G. molesta, is attracted to male sex pheromone composed of methyl epijasmonate (42) and ethyl (E)-cinnamate (43). Males of oriental fruit fly, B. dorsalis, pharmacophagously acquire methyl eugenol (44) from plants and biotransform to sex pheromone 2-allyl-4,5-dimethoxyphenol (45) and (E)-coniferyl alcohol (46), which entice females during courtship.…”

Sequestration of aristolochic acids from meridic diets by larvae of Battus polydamas archidamas (Papilionidae: Troidini)

“…For example, some Danaine and Ithomiine butterflies (Nymphalidae) are associated with pyrrolizidine alkaloids that occur in plants belonging to a wide variety of families (e.g. Asteraceae, Boraginaceae, Apocynaceae) (Nishida et al, 1991(Nishida et al, , 1996Honda et al, 1997;Nishida, 2002). These compounds can be used as oviposition stimulants by females, as sex pheromones by males and for defence by larvae, which sequester them during their development (Nishida, 2002).…”