| 摘要 |
<p>Antirachitic preparations obtained by the irradiation of ergosterol are purified by causing their inactive components to form double compounds with maleic or citraconic acid anhydrides and separating these compounds by their insolubility in suitable solvents, for example, petroleum ether. The irradiated ergosterol is dissolved in an organic solvent, for example, benzene or a mixture of ether and petroleum ether, a slight excess of maleic or citraconic acid anhydride is added at normal or slightly elevated temperature, and the mixture allowed to stand until the double compound is formed. The solvent is evaporated, the residue containing the addition compound dissolved in alcoholic potash, the solution heated after adding water, and repeatedly extracted with petroleum ether, or successively with ether and petroleum ether. The extracts contain the active component, from which the petroleum ether is then removed by evaporation. The residue may subsequently be dissolved in a vegetable oil, or may be recrystallized from methyl alcohol or acetone. Oxygen is excluded during the process. Examples are given.</p> |
