|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1994 : ¥400,000 (Direct Cost : ¥400,000)
Fiscal Year 1993 : ¥1,700,000 (Direct Cost : ¥1,700,000)
(1) In ovaries and eggs of the silkworm, Bombyx mori, eight free ecdysteroids and their phosphoric edsters have already been identified. We recently demonstrated that various unidentified ecdysteroids are still present in mature ovaries and developing eggs of the silkworm, Bombyx mori. In the present study, ten unidentified ecdysteroids were isolated from 9 Kg eggs of Bombyx silkworm by several chromatographic techniques, e.g. liquid chromatography on silicic acid column, and HPLC on reverse-phase and anion-exchange columns. Their structures were analyzed by means of FAB-mass spectrometry, EI-mass spectrometry and NMR specroscopy. The structures of their ecdysteroids were determined as 22-deoxy-20-hydroxyecdysone and its 3-phosphate, 3-epi-22-deoxy-20-hydroxyecdysone and its 2-phosphate, 3-epi-22-deoxy-2-, 26-dihydroxyecdysone and its 2-phosphate, 3-epi-22-deoxy-16 (beta), 20-dihydroxyecdysone and its 2-phosphate, and 2,22-dideoxy-23 (s) -hydroxy-ecdysone and its 3-phosphate. These ecdysteroids were newly isolated in the present study.
(2) In the present study, in order to compare the metabolism of ecdysone between the diapause eggs and non-diapause eggs, [^3H] ecdysone or [^3H] ketodiol was injected into two types of eggs. The resultant radioactive metabolits were analyzed by a reverse-phase HPLC.In the diapause eggs, most of the radioactivity was detected in the conjugated ecdysteroid fraction (mainly, 3-epi-ecdysone 22-phosphate). On the other hand, in the non-diapause eggs, the radioactivity was scarcely detected in the conjugate ecdysteroid fraction, alternatively most of the radioactivity efficiently converted to 3-epi-20,26-dihydroxyecysone via 20-hydroxyecdysone. These results suggest that the ecdysteroid metabolism in the eggs of the silkworm is closely related to the fate of embryonic development.