DZ-PHENYLALANINE

The enzymatic approach for the synthesis of aspartame has the advantage of producing only the (Z,)-a-aspartyl compound (the sweet diastereomer). The less expensive racemic (DZ)-phenylalanine can be used as the starting material. The unreacted (D)-phenylalanine can be recovered and racemized for further reaction. By contrast, the chemical methods used industrially also produce the (L)-p-aspartyl compound (non-sweet) in 10-40% yield, for which a purification step is needed. In 1999, the world market for enzymatically synthesized aspartame was reported to be 800 million US [13]. 

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