Structural analysis and metabolism of oo-ecdysteroids of the silkworm, Bombyx mori

(1)在家蚕卵巢和卵中已鉴定出8种游离蜕皮甾体及其磷酸化酯。我们最近发现，在家蚕的成熟卵巢和发育中的卵中仍然存在各种未鉴定的蜕皮甾体。本研究采用高效液相色谱法，即反相柱色谱法、阴离子交换柱色谱法，从9 kg家蚕卵中分离得到10种未鉴定的蜕皮甾体化合物。通过FAB-质谱、EI-质谱和NMR等手段对其结构进行了分析。它们的蜕皮甾体化合物的结构分别为22-脱氧-20-羟基蜕皮酮及其3-磷酸盐、3-表-22-脱氧-20-羟基蜕皮酮及其2-磷酸盐、3-表-22-脱氧-2，26-二羟基蜕皮酮及其2-磷酸盐、3-表-22-脱氧-16（β），20-二羟基蜕皮酮及其2-磷酸盐和2，22-双脱氧-23（s）-羟基-蜕皮激素及其3-磷酸盐。这些蜕皮甾体是本研究中新分离的。(2)本研究将[^3H]蜕皮激素或[^3H]酮二醇分别注射到滞育卵和非滞育卵中，比较两种卵蜕皮激素代谢的差异。在滞育卵中，大部分放射性物质在结合型蜕皮甾体组分（主要是3-epi-ecdysone 22-phosphate）中检测到。另一方面，在非滞育卵中，在结合蜕皮甾类组分中几乎未检测到放射性，或者大部分放射性通过20-羟基蜕皮激素有效转化为3-表-20，26-二羟基蜕皮激素。这些结果表明，蚕卵中蜕皮激素的代谢与胚胎发育的命运密切相关。

(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.