| 摘要 |
NEW MATERIAL:A compound expressed by formula I [R1 represents H, halogen atom, OH, OR (R represents alkyl) or formula II (R' and R'' represent H, R, heterocyclic group, etc.); R2 represents H or halogen atom; R3 and R4 represent OH, OR, formula II, etc.; R5 represents H, R or COR; R6 represents H, halogen atom, OSO2R, etc.]. USE:An antitumor agent. PREPARATION:For example, DC-45A2 is dissolved in acetic anhydride, stirred for a whole day and night and concentrated under reduced pressure. The concentrated residue is dissolved in chloroform, washed and dried and then concentrated under reduced pressure. The product is separated by silica-gel chromatography. Then the fraction corresponding to the Rf value is concentrated under reduced pressure and the concentrate is purified again by silica-gel chromatography. The purified product is reacted with pyridinium chlorochromate in methylene chloride at room temperature for 1hr and concentrated under reduced pressure and the residue is purified by silica-gel chromatography to afford the compound expressed by formula I. |
