| 摘要 |
The invention relates to a process for the preparation of beta -sitosterol having a low content of alpha -sitosterol of a sterol mixture isolated from the unsaponifiables obtained from crude soap from the sulphate cellulose process. The invention is based on crystallization of the sterol mixture from a mixture of an organic solvent and water, preferably 1,2-dichloroethylene or methyl ethyl ketone and water. By means of the process according to the invention, from starting materials containing 20 to 25% alpha -sitosterol is obtained a product which contains less than 5% alpha -sitosterol and which, when required, can be retreated by means of the process according to the invention to obtain beta -sitosterol containing less than 1% alpha -sitosterol. When using methyl ethyl ketone as organic solvent, beta -sitosterol is also purified of any betulin contained in the starting material. |
