アメバシリン

純化方法Forty grams of a commercial sample containing 42% fumagillin, 45% sucrose, 10% antifoam agent and 3% of other impurities are digested with 150mL of CHCl3. The insoluble sucrose is filtered off and washed with CHCl3. The combined CHCl3 extracts are evaporated almost to dryness at room temperature under reduced pressure. The residue is triturated with 20mL of MeOH, and the fumagillin is filtered off by suction. It is crystallised twice from 500mL of hot MeOH by standing overnight in a refrigerator (yellow needles). (The long-chain fatty ester used as antifoam agent is still present, but is then removed by repeated digestion, on a steam bath, with 100mL of diethyl ether.) For further purification, the fumagillin (10g) is dissolved in 150mL of 0.2M ammonia, and the insoluble residue is filtered off. The ammonia solution (cooled in running cold water) is then brought to pH 4 by careful addition of M HCl with constant shaking in the presence of 150mL of CHCl3. (Fumagillin is acid-labile and must be removed rapidly from the aqueous acid solution.) The CHCl3 extract is washed several times with distilled water, dried (Na2SO4) and evaporated under reduced pressure. The solid residue is washed with 20mL of MeOH. The fumagillin is filtered off by suction, then crystallised from 200mL of hot MeOH. [Tarbell et al. J Am Chem Soc 77 5610 1955.] Alternatively, 10g of fumagillin in 100mL CHCl3 is passed through a silica gel (5g) column to remove tarry material, and the CHCl3 is evaporated to leave an oil which gives fumagillin on crystallisation from amyl acetate. It recrystallises from MeOH (charcoal) or Me2CO/MeOH. The fumagillin is stored in dark bottles in the absence of oxygen and at low temperatures. [Schenk et al. J Am Chem Soc 77 5606 1955, Beilstein 19 III/IV 1012.]