Synthesis of Silica-anchored Sensitizer and its Application in the Preparation of Previtamin D_3 from Tachysterol

A silica gel-anchored photosensitizer was synthesized with anthracene as sensitizer moiety. The photoisomerization of tachysterol to previtamin D3 was carried out with this heterogeneous photosensitizer in ethanol. The experiment results demonstrate that this solid phase photosensitizer is efficient for the photoisomerization and can be simply separated from the reaction mixture by filtration.

Synthesis of Polymer-bound Sensitizers and their Applications in the Preparation of Previtamin D_3 from Tachysterol

Two kinds of polymer-bound photosensitizers were synthesized, in which anthracene acts as sensitizer moiety, polystyrene (PS) and poly(methyl methylacrylate) (PMMA) serve as solid phase supports, respectively. The photoisomerization of tachysterol to previtamin D3 was carried out with these polymer-bound photosensitizers in ethanol and toluene solutions. The experiment results demonstrate that these solid phase photosensitizers are effi-cient for the photoisomerization with good recycle property and can be simply separated from the reaction mixtures by filtration.

维生素D原体浓度对它的光异构反应的影响

目的：研究乙醇溶液中维生素 Ｄ 原体浓度对它的光异构反应产物产率的影响。方法：用两种紫外光激发光源光照不同浓度的维生素 Ｄ 原体乙醇溶液，使用正相 Ｈ Ｐ Ｌ Ｃ 系统定量测定主要光异构物在溶液中的浓度。结果：数据表明，随维生素 Ｄ 原体浓度的增加，速甾醇产率减少，而光甾醇产率明显增加。维生素 Ｄ 前体产率变化，与所用的激发光源有关。结论：维生素 Ｄ 原体浓度对其光异构反应产物产率的影响较大，特别对速甾醇和光甾醇，利用光自吸收效应有助于设计光化学法合成药物及制备高产率的光异构产物。

二维液相色谱法测定维生素D2软胶囊中速甾醇的含量

目的建立二维液相色谱法检测维生素D2软胶囊中速甾醇含量的方法。方法检测波长281 nm;流速0.5 mL·min-1;柱温40℃;一维色谱条件:采用Thermo Acclaim HILIC丙基酰胺键合硅胶柱(2.1 mm×150 mm,3μm),以正己烷-正戊醇-异丙醇(998∶0.5∶1.5)为流动相;二维色谱条件:采用Thermo硅胶柱(3 mm×100 mm,1.8μm),以正己烷(A)-正己烷-正戊醇-异丙醇(96∶2∶2)(B)为流动相,梯度洗脱。结果速甾醇在0.032 5~0.325μg·mL^-1内与峰面积的线性关系良好,r=0.999 9;回收率为99.35%(RSD=1.4%,n=9),速甾醇的相对校正因子为0.047 6,检测限为1.6ng·mL^-1,定量限为4.8 ng·mL^-1。结论建立的方法符合杂质测定的要求,可以准确测定维生素D2软胶囊中速甾醇的含量。