| abstract |
A method for producing an alpha-L-aspartyl-L-phenylalanine-beta-ester (also named alpha-L-(beta-o-substituted aspartyl)-L-phenylalanine), which is an intermediate of an alpha-L-aspartyl-L-phenylalanine-alpha-methyl ester (also named alpha-L-aspartyl-L-phenylalanine methyl ester; product name: aspartame), easily, at high yield and inexpensively without going through a complex synthesis method is provided. Further, an easy, inexpensive and high-yield production method for an alpha-L-aspartyl-L-phenylalanine-alpha-methyl ester is provided. alpha-L-aspartyl-L-phenylalanine-alpha-methyl ester is produced from a L-aspartic acid-alpha,beta-diester and L-phenylalanine using an enzyme or enzyme-containing substance that has an ability to catalyze a reaction in which L-phenylalanine performs no nucleophilic attack on a beta-ester site of L-aspartic acid-alpha,beta-diester but performs a nucleophilic attack on an alpha-ester site thereof. |