| 摘要 |
<p>PURPOSE:To prepare a highly pure alpha-L-aspartyl-L-phenylalanine lower alkyl ester useful as a new sweetening, economically, by purifying the ester containing impurities with a Cl-type anion exchange resin. CONSTITUTION:An alpha-L-aspartyl-L-phenylalanine lower alkyl ester (e.g. alpha-L- aspartyl-L-phenylalanine methyl ester) containing diketo-piperazine, alpha-L-aspartyl- L-phenylalanine, etc. as impurities is brought into contact with a Cl-type anion exchange resin, preferably a strongly basic one, in water or its mixture with methanol, acetone, etc. The impurities are adsorbed to the anion exchange resin, and removed.</p> |
