Abstract

Toratane Munegumi^1,2*, Takeshi Fujimoto², MichioTakada², and NozomiNagashima²

DOI : http://dx.doi.org/10.13005/ojc/300103

Alanine anhydrides (Cyclo-(Ala-Ala)) are the simplest dipeptides that have two chiral centers and three diastereomers: Cyclo-(L-Ala-L-Ala), Cyclo-(D-Ala-D-Ala), and Cyclo-(L-Ala-D-Ala).Analysis of the epimerization of these peptides may throw light on the development of homochirality in proteins. We show that the epimerization rate of Cyclo-(L-Ala-L-Ala) and Cyclo-(D-Ala-D-Ala) is higher than that of Cyclo-(L-Ala-D-Ala), while the ring-opening rates of Cyclo-(L-Ala-L-Ala) and Cyclo-(D-Ala-D-Ala) arelower than that of Cyclo-(L-Ala-D-Ala) in basic aqueous solutions. The total reaction resulted in the preferred stability of Cyclo-(L-Ala-L-Ala) and Cyclo-(D-Ala-D-Ala) to Cyclo-(D-Ala-L-Ala).

cyclic dipeptide; epimerization; ring-opening reaction; homochirality

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