Quisqualic acid
 quisqualic acid
Tsunematsu Takemoto et al. (Tohoku Uni.) found this compound from the seed of Quisqualis indica and named it after the genus name, Quisqualis.   It is thought that this compound is biosynthesised through the precursors, 2,3-di amino propionic acid and its derivative, 2-amino-3-ureide propionic acid.

CAS No. 52809-07-1
Molecular formula C5H7N3O5
Molecular weight 189.127
IUPAC Name (2S)-2-amino-3-(3,5-dioxo-1,2,4-oxadiazolidin-2-yl) propanoic acid

The fruit of Rangoon creeper, Shikunshi, which contains quisqualic acid, that has anthelmintic effect, is effective treatment for roundworm (Ascaris lumbricoides) and pinworm (Enterobius vermicularis).
Same as NMDA (N-methyl-D-aspartic acid) and kainic acid, quisqualic acid is one of the excitatory amino acids which transmits excitatory stimulation.  It has neurotoxicity.  Quisqualic acid opens calcium channels in the cell membrane, the increased calcium levels continue to activate enzymes, such as protease.  When the enzymes are excessively activated, this causes cell damage.  In the field of neuroscience, quisqualic acid is used for selectively destroying nerve cells in the brain or medulla spinalis.
n-methyl-d-aspartic_acid kainic_acid
N-methyl-D-aspartic acid             kainic acid