Abstract: A method of producing an ?-L-aspartyl-L-phenylalanine-?-ester by forming the ?-L-aspartyl-L-phenylalanine-?-ester from L-aspartic acid-?,?-diester and L-phenylalanine using an enzyme or enzyme-containing substance that has an ability to selectively link L-phenylalanine to an ?-ester site of the L-aspartic acid-?,?-diester through a peptide bond.

Abstract: A method of producing an ?-L-aspartyl-L-phenylalanine-?-ester by forming the ?-L-aspartyl-L-phenylalanine-?-ester from L-aspartic acid-?,?-diester and L-phenylalanine using an enzyme or enzyme-containing substance that has an ability to selectively link L-phenylalanine to an ?-ester site of the L-aspartic acid-?,?-diester through a peptide bond.

Abstract: A method of producing an ?-L-aspartyl-L-phenylalanine-?-ester by forming the ?-L-aspartyl-L-phenylalanine-?-ester from L-aspartic acid-?,?-diester and L-phenylalanine using an enzyme or enzyme-containing substance that has an ability to selectively link L-phenylalanine to an ?-ester site of the L-aspartic acid-?,?-diester through a peptide bond.

Abstract: A method of producing an ?-L-aspartyl-L-phenylalanine-?-ester by forming the ?-L-aspartyl-L-phenylalanine-?-ester from L-aspartic acid-?,?-diester and L-phenylalanine using an enzyme or enzyme-containing substance that has an ability to selectively link L-phenylalanine to an ?-ester site of the L-aspartic acid-?,?-diester through a peptide bond.

Abstract: A method of producing an ?-L-aspartyl-L-phenylalanine-?-ester by forming the ?-L-aspartyl-L-phenylalanine-?-ester from L-aspartic acid-?,?-diester and L-phenylalanine using an enzyme or enzyme-containing substance that has an ability to selectively link L-phenylalanine to an ?-ester site of the L-aspartic acid-?,?-diester through a peptide bond.

Abstract: A method of producing an ?-L-aspartyl-L-phenylalanine-?-ester by forming the ?-L-aspartyl-L-phenylalanine-?-ester from L-aspartic acid-?,?-diester and L-phenylalanine using an enzyme or enzyme-containing substance that has an ability to selectively link L-phenylalanine to an ?-ester site of the L-aspartic acid-?,?-diester through a peptide bond.

Abstract: A method of producing an ?-L-aspartyl-L-phenylalanine-?-ester by forming the ?-L-aspartyl-L-phenylalanine-?-ester from L-aspartic acid-??-diester and L-phenylalanine using an enzyme or enzyme-containing substance that has an ability to selectively link L-phenylalanine to an ?-ester site of the L-aspartic acid-??-diester through a peptide bond.

Abstract: A method of producing an ?-L-aspartyl-L-phenylalanine-?-ester by forming the ?-L-aspartyl-L-phenylalanine-?-ester from L-aspartic acid-??-diester and L-phenylalanine using an enzyme or enzyme-containing substance that has an ability to selectively link L-phenylalanine to an ?-ester site of the L-aspartic acid-??-diester through a peptide bond.

Abstract: A method for producing an ?-L-aspartyl-L-phenylalanine-?-ester (also named ?-L-(?-o-substituted aspartyl)-L-phenylalanine), which is an intermediate of an ?-L-aspartyl-L-phenylalanine-?-methyl ester (also named ?-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 ?-L-aspartyl-L-phenylalanine-?-methyl ester is provided. ?-L-aspartyl-L-phenylalanine-?-methyl ester is produced from a L-aspartic acid-?,?-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 ?-ester site of L-aspartic acid-?,?-diester but performs a nucleophilic attack on an ?-ester site thereof.

Abstract: A method for producing an ?-L-aspartyl-L-phenylalanine-?-ester (also named ?-L-(?-o-substituted aspartyl)-L-phenylalanine), which is an intermediate of an ?-L-aspartyl-L-phenylalanine-?-methyl ester (also named ?-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 ?-L-aspartyl-L-phenylalanine-?-methyl ester is provided. ?-L-aspartyl-L-phenylalanine-?-methyl ester is produced from a L-aspartic acid-?,?-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 ?-ester site of L-aspartic acid-?,?-diester but performs a nucleophilic attack on an ?-ester site thereof.

Abstract: A method for producing an ?-L-aspartyl-L-phenylalanine-?-ester (also named ?-L-(?-o-substituted aspartyl)-L-phenylalanine), which is an intermediate of an ?-L-aspartyl-L-phenylalanine-?-methyl ester (also named ?-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 ?-L-aspartyl-L-phenylalanine-?-methyl ester is provided. ?-L-aspartyl-L-phenylalanine-?-methyl ester is produced from a L-aspartic acid-?,?-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 ?-ester site of L-aspartic acid-?,?-diester but performs a nucleophilic attack on an ?-ester site thereof.

Abstract: A method for producing an ?-L-aspartyl-L-phenylalanine-?-ester (also named ?-L-(?-o-substituted aspartyl)-L-phenylalanine), which is an intermediate of an ?-L-aspartyl-L-phenylalanine-?-methyl ester (also named ?-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 ?-L-aspartyl-L-phenylalanine-?-methyl ester is provided. ?-L-aspartyl-L-phenylalanine-?-methyl ester is produced from a L-aspartic acid-?,?-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 ?-ester site of L-aspartic acid-?,?-diester but performs a nucleophilic attack on an ?-ester site thereof.

Abstract: The present invention relates to a novel process for producing an N-formyl-neutral-amino acid and N-formylaspartic acid. The present invention also relates to a novel process for producing N-formyl-&agr;-L-aspartyl-L-phenylalanine methyl ester as a precursor of aspartame and aspartame, as well as a method of making a precursor of aspartame and aspartame by using the same.