Synthesis and recovery of aspartame involving enzymatic deformylation step

Method for the preparation and recovery of α-L-aspartyl-L-phenylalanine methyl ester by enzymatic deformylation of an N-formyl-α-L-aspartyl-L-phenylalanine compound, characterized in that either

• (i) a mixture of N-formyl-α- and N-formyl-β-L-aspartyl-L-phenylalanine or
• (ii) a mixture of N-formyl-α- and N-formyl-β-L-aspartyl-L-phenylalanine methyl ester is treated with an enzyme having formylmethionyl peptide deformylase activity and having as a co-factor bivalent metal ions chosen from the group of group 5 to 11 metals from the periodic system of elements, with the formation of α-L-aspartyl-L-phenylalanine or of its methyl ester, respectively, whereby in case α-L-aspartyl-L-phenylalanine is formed in the deformylation step a subsequent methylation step of the phenylalanine carboxylic acid group is carried out, and the α-L-aspartyl-L-phenylalanine methyl ester is recovered.

Method for synthesis of α-L-aspartyl-L-phenylalanine methyl ester by enzymatic deformylation of an N-formyl-α-L-aspartyl-L-phenylalanine compound, characterized in that N-formyl-L-aspartic acid is coupled enzymatically, using thermolysin as the coupling enzyme, with L- or D,L-phenylalanine methyl ester, and that simultaneously, and in the same reaction vessel, the N-formyl-α-L-aspartyl-L-phenylalanine methyl ester formed by the coupling reaction is deformylated by an enzyme having formylmethionyl peptide deformylase activity and having as a co-factor bivalent metal ions chosen from the group of group 5 to 11 metals from the periodic system of elements and being present in the reaction system for the enzymatic coupling reaction.