Deracemization of amino acids by partial sublimation and via homochiral self-organization.

Deracemization of a 50/50 mixture of enantiomers of aliphatic amino acids (Ala, Leu, Pro, Val) can be achieved by a simple sublimation of a pre-solubilized solid mixture of the racemates with a huge amount of a less-volatile optically active amino acid (Asn, Asp, Glu, Ser, Thr). The choice of chirality correlates with the handedness of the enantiopure amino acids--Asn, Asp, Glu, Ser, and Thr. The deracemization, enantioenrichment and enantiodepletion observed in these experiments clearly demonstrate the preferential homochiral interactions and a tendency of natural amino acids to homochiral self-organization. These data may contribute toward an ultimate understanding of the pathways by which prebiological homochirality might have emerged.