| 摘要 |
NEW MATERIAL:A compound of the formula (R is H, acetyl). EXAMPLE:23-0-Acetyl-thyrsiferol. USE:Antitumor agent. PREPARATION:For example, MAGIRESOZO (a red alga: Leurencia obtsusa) is extracted with a hydrophilic organic solvent such as methanol, the resultant extract is dissolved in a hydrophobic organic solvent such as ether, and the solution is washed with water, then preferably washed with aqueous alkali and aqueous acid. Then, the product is adsorbed to an activated adsorbent such as silica gel, eluted with benzene and the resultant eluate is subjected to partition chromatography to effect separation and purification to give a compound of formula I. The product is acetylated, preferably in the presence of a base such as triethylamine to give another compound of the formula, where R is acetyl.
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