A new application of molecularly imprinted materials.

We have studied the possibility of shifting a thermodynamically unfavourable enzymatic equilibrium towards product formation via the addition of a highly specific adsorbent. The commercially interesting enzymatic condensation of Z-L-aspartic acid with L-phenylalanine methyl ester to the sweetener aspartame was chosen as the model system. Extremely stable and specific adsorbents for the product Z-L-Asp-L-Phe-OMe (Z-aspartame) were prepared using the emerging technique of molecular imprinting. A considerable increase (40%) in the yield of product was obtained when such adsorbents were present during the enzymatic reaction. The message of this investigation is that the use of such specific, sterilizable adsorbents should be considered for enzymatic processes to increase the yield. Finally, the direct isolation of a product formed by the retrieval of the adsorbents carrying the product can be envisaged, especially if the adsorbents are magnetic.