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

(1)在家蚕（Bombyx mori）的卵巢和卵中，已鉴定出8种游离的表皮甾体及其磷酯。我们最近证明，在家蚕的成熟卵巢和发育中的卵中仍然存在各种不明的表皮类固醇。本研究采用硅酸柱液相色谱、反相柱和阴离子交换柱高效液相色谱等色谱技术，从9 Kg家蚕卵中分离得到10种未鉴别的表皮甾体。用fab -质谱、ei -质谱和核磁共振谱分析了它们的结构。它们的蜕皮激素结构分别为22-脱氧-20-羟基蜕皮酮及其3-磷酸、3-外皮-22-脱氧-20-羟基蜕皮酮及其2-磷酸、3-外皮-22-脱氧-2-、26-二羟基蜕皮酮及其2-磷酸、3-外皮-22-脱氧-16 （β）、20-二羟基蜕皮酮及其2-磷酸、2,22-二脱氧-23 (s) -羟基蜕皮酮及其3-磷酸。这些外甾体是本研究中新分离到的。(2)在本研究中，为了比较滞育卵与非滞育卵对蜕皮激素的代谢，将[^3H]蜕皮激素或[^3H]酮二醇注射到两种卵中。所得放射性代谢物用反相高效液相色谱分析。在滞育卵中，检测到的放射性主要集中在共轭蜕皮激素部分（主要是3-表蜕皮激素22-磷酸）。另一方面，在非滞育卵中，偶联蜕皮激素部分几乎检测不到放射性，大部分放射性通过20-羟基蜕皮激素有效转化为3-epi-20,26-二羟基蜕皮激素。这些结果表明，家蚕卵的表皮甾体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.