Racemate

This is a Mixture of D and L optical stereoisomers (enantiomorphs) which subsequently becomes optically inactive. All naturally synthesized amino acids are in the L form but degradation generates the D enantiomorph. The degree of racemization of aspartic acid is faster than that of other amino acids. It has been recently used to determine the authenticity of ancient samples of DNA because the degradation of DNA and the racemization of amino acids, particularly Asp, indicate whether the spurious DNA is really ancient or just a contaminant