| 摘要 |
PURPOSE:To obtain the subject composition extremely suitable as a synthetic intermediate for mammal dolichols by extracting leaves of ginkgo or cedar with lipophilic organic solvent and separating the resultant extract by chromatography, etc. CONSTITUTION:Leaves of ginkgo or ceder are extracted with a lipophilic organic solvent and the extract is optionally hydrolyzed and then subjected to separation process comprising chromatography, fractional dissolution, fractional freeze-precipitation, molecular distillation or their combination to obtain the objective polyprenyl composition composed of a mixture of plural kinds of the compounds of formula I (A1 is OH or acetyloxy; group of formula II is trans-unit; group of formula III is cis-unit; (n) is 11-19) and containing >=70wt.% (in total) of the compounds of (n)=14, (n)=15 and (n)=16 as essential components. Preferably, the contents of the compounds of (n)=14, (n)=15 and (n)=16 are 20-35wt.%, 30-50wt.% and 10-25wt.%, respectively. |
