IUCr journals


Acta Cryst. (2007). E63, o3802-o3803 [doi:10.1107/S1600536807039505]

[l-asparagine] A packing diagram of L-asparagine. Broken lines indicate the hydrogen bonds.
L-Asparagine is one of the fundamental natural amino acid residues in proteins. Amino acids very often have polymorphs. In this study, for the first time, a single-crystal structure determination of anhydrous L-asparagine is reported. The molecules are in their zwitterionic form. Although the carboxyl group is deprotonated, the distances of the two C...O bonds are significantly different due to different hydrogen-bond environments. The conformation of the side chain is trans, which distinguishes it significantly from that of the amino acid monohydrates.

K. Yamada, D. Hashizume, T. Shimizu and S. Yokoyama