Summary
N-(Benzyloxycarbonyl)-l-asparty-l-phenylalanine methyl ester, the precursor of the synthetic sweetener aspartame, was continuously synthesized in an immobilized thermolysin plug-flow type reactor at 25° C with the substrates (N-benzyloxycarbonyl-l-aspartic acid and l-phenylalanine methyl ester) dissolved in ethyl acetate. The immobilized enzyme was quite stable in ethyl acetate containing 2.5% 0.01 M 2-(N-morpholino)ethanesulphonic acid-NaOH buffer, pH 6.0, and 20 mM CaCl2 with or without the substrate at 25° C. By periodically washing the column, we could conduct a continuous reaction for over 500 h with an average yield of 95% and a space velocity of 1.85 h −1.
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References
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Nakanishi, K., Takeuchi, A. & Matsuno, R. Long-term continuous synthesis of aspartame precursor in a column reactor with an immobilized thermolysin. Appl Microbiol Biotechnol 32, 633–636 (1990). https://doi.org/10.1007/BF00164731
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DOI: https://doi.org/10.1007/BF00164731