RESUMEN
Objective: To separate antitumor constituent AD-1 [20(R)-25-OCH3-protopanoxadiol (PPD)] from non-racemic enatiomeric mixture. Methods: A crystallization method has been developed to separate AD-1 from 25-OCH3-PPD non-racemic enatiomeric mixture, the sorts and amount of solvent and crystallization temperature were optimized to obtain the best separative conditions, and the relationship between the S/R percentage of 25-OCH3-PPD non-racemic enantiomeric mixture and dielectric constant of the solvent was discussed. Results: Under the optimized conditions (acetone 26 mL, 4°C), the yield and purity of AD-1 crystals are 38.76% and 97.83% from 25-OCH3-PPD non-racemic enatiomeric mixture (R: 59.34%; S: 38.35%), respectively. Conclusion: The ε values of solvents are about 20.7, and an unsaturated solution and low temperature are beneficial to the separation of AD-1 from 25-OCH3-PPD non-racemic enatiomeric mixture.