|Budget Amount *help
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2000: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1999: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1998: ¥2,100,000 (Direct Cost: ¥2,100,000)
Male danaid butterfly of many species is well-known to visit Boraginaceae plants and sucks with its proboscis the pyrrolizidine alkaloids-containing exudation, which was defined as pharmacophagous behavior. The male stores the alkaloids as defensive substances and/or manufactures aphrodisiacal substances from the alkaloids and uses them in its courtship display to attract the female butterfly. The males of danaid butterflies such as Salatura genutia (CRAMER), Ideopsis similis (LINNAEUS), Euploea mulciber (CRAMER), Parantica sita (KOLLAR), and Anosia chrysippus (LINNAEUS) which inhabit in Okinawa also visited Messerschmidia argentea Johnst (Boraginaceae) and sucked dewdrops on the fresh twigs and their own saliva on the dead twigs of the plant. In some species, the same pharmacophagous behavior is observed for not only the male butterflies but also the female ones. I examined the differential effects of constituents from M.argentea on pharmacophagous behavior of the male and female dana
A water extract of the twigs of M.argentea was subjected to gel filtration chromatography on Sephadex G-25 and then column chromatography on silica gel to give a basic fraction which stimulated ingestion of it by the male and female butterflies. The fraction was, moreover, subjected to preparative TLC to give four pyrrolizidine alkaloids (PAs) such as 3'-acetylindicine (1), indicine (2), 3'-acetylindicine-N-oxide (3), indicine-N-oxide (4), 6'-methylindicine (5), and 6'- methylindicine-N-oxide (6).
Phagostimulant tests of PAs 1-6 against the adult males and females of danaid butterflies were done. The male butterflies of S.genutia ingested 1-4. The female ones ingested only 4, but did a sample mixed 4 such as 1 + 2 + 3 + 4 + 5 + 6. Thus, each of the alkaloid 1-4 was a stimulant of the pharmacophagous behavior into the males of S.genutia and 4 into the females. On the basis of phagostimulant test for other butterflies, the alkaloid 3 was found to be a stimulant of the pharmacophagous behavior into the males of I.similis, 3 and 4 into of the females of I.similis, . Each of the alkaloid 1-4 was a stimulant of the pharmacophagous behavior into the males and females of E.mulciber. Each of the alkaloid 1-4 was a stimulant of the pharmacophagous behavior into the males of P.sita and 3 and 4 into females of P.sita. he alkaloid 4 was a stimulant of the pharmacophagous behavior into of the males of A.chrysippus. The female butterflies of A.chrysippus was not stimulated by the water extract and each pyrrolizidine alkaloid. Less