QUISQUALIC ACID Property

Melting point:

185-187°C dec.

alpha 

D20 +17.0° (c = 2.0 in 6M HCl)

Boiling point:

324.36°C (rough estimate)

Density 

1.6649 (rough estimate)

refractive index 

1.6190 (estimate)

storage temp. 

2-8°C

solubility 

NH₄OH 1 M: 20 mg/mL, clear, colorless

pka

2.12±0.10(Predicted)

form 

powder

color 

white to off-white

Water Solubility 

Soluble in ethanol, water. Insoluble in organic solvents.

Merck 

13,8177

BRN 

1078734

Stability:

Stable. Incompatible with strong oxidizing agents.

Safety

Hazard Codes 

Xn

Risk Statements 

20/21/22

Safety Statements 

26-36

WGK Germany 

3

F 

10

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H302Harmful if swallowed

H312Harmful in contact with skin

H332Harmful if inhaled

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P304+P340IF INHALED: Remove victim to fresh air and Keep at rest in a position comfortable for breathing.

P321Specific treatment (see … on this label).

QUISQUALIC ACID Chemical Properties,Usage,Production

Description

L-Quisqualic acid is a natural analog of glutamate that acts as an agonist at AMPA-selective and metabotropic glutamate receptors (EC₅₀s = 170, 10, 40, and 29 nM at GluR-A, mGluR1, mGluR3, and mGluR5, respectively), as well as the ionotropic kainate receptor (GRIK4; K_i = 6.43 nM). L-Quisqualic acid is used to study receptor dynamics and as an excitotoxin to selectively destroy neurons in the brain or spinal cord.

Chemical Properties

Off-White Solid

Uses

An amino acid that is able to function as an agonist at multiple excitatory amino acid receptor substrates in the central nervous system. It also has high affinity for the kainate, AMPA and the metabotropic receptors. Inhibits the Ca2+/Cl-dependent glutamic acid uptake system in brain synaptic plasma membrane preparations.

Uses

Quisqualic acid has been used to test ligand-gated receptors in spiral ganglion neurons.

Uses

Quisqualic acid is used to differentiate between mGluR-1 and mGluR-4. L-Quisqualic acid is an activator of GluR.

Definition

ChEBI: Quisqualic acid is a non-proteinogenic alpha-amino acid.

General Description

Quisqualate/ Quisqualic acid is obtained from the fruits and seeds of Quisqualis chinensis. It is an agonist at two subsets of excitatory amino acid receptors metabotropic receptors that indirectly mediate calcium mobilization from intracellular stores and, ionotropic receptors that directly control membrane channels. L-quisqualic acid is an agonist of the neurotransmitter L-glutamate.

Biological Activity

Glutamate receptor agonist acting at AMPA receptors and metabotropic glutamate receptors positively linked to phosphoinositide hydrolysis. Sensitizes neurons in hippocampus to depolarization by L-AP6 (the so called 'quis' effect). Also available as part of the Group I mGlu Receptor Tocriset™ .

Biochem/physiol Actions

Active enantiomer of quisqualic acid; excitatory amino acid at glutamate receptors.

storage

Store at RT

Purification Methods

It has been purified by ion-exchange chromatography on Dowex 50W (x 8, H+ form); the desired fractions are lyophilised and recrystallised from H2O/EtOH. It has IR (KBr) : 3400-2750br, 1830s, 1775s, 1745s and 1605s cm-1;maxand 1H NMR (NaOD/D2O, pH 13) : 3.55-3.57 (1H m, X of ABX, H-2), 3.72-3.85 (2H, AB of ABX, H-3), 1 3C NMR (D2O) : 50.1t, 53.4d, 154.8s, 159.7s and 171.3s. [Baldwin et al. J Chem Soc, Chem Commun 256 1985.] It is a quasiqualate receptor agonist [Joels et al. Proc Natl Acad Sci USA 86 3404 1989].