Potassium asparaginate

Not to be confused with potassium aspartate, a salt of L-aspartic acid, a different amino acid.

Potassium asparaginate is a potassium salt of L-asparagine amino acid.^[2][3][4][5]

Potassium asparaginate

Names
IUPAC name L-Asparagine potassium salt
Other names L-Asparagine, potassium salt (1:1); L-Asparagine, monopotassium salt; Asparagine potassium
Identifiers
CAS Number	37707-20-3
3D model (JSmol)	Interactive image
ChemSpider	32700657
PubChem CID	23688210
UNII	P1CVX5FD7Y
CompTox Dashboard (EPA)	DTXSID00191144
InChI InChI=1S/C4H8N2O3.K/c5-2(4(8)9)1-3(6)7;/h2H,1,5H2,(H2,6,7)(H,8,9);/q;+1/p-1/t2-;/m0./s1 Key: NRFNNNBFDIFBLS-DKWTVANSSA-M
SMILES [K+].N[C@@H](CC(N)=O)C([O-])=O
Properties
Chemical formula	C4H7KN2O3
Molar mass	170.209 g·mol−1
Solubility in water	16 g/100ml (30 °C) 22 g/100ml (35 °C) 28 g/100ml (40 °C)[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Potassium asparaginate can be considered both a salt and a coordination complex.^[6][3] As a salt, potassium asparaginate is formed when the potassium ion (K⁺) replaces the hydrogen ion (H⁺) in the carboxyl group (–COOH) of L-asparagine, an amino acid.^[3] As a coordination complex, in the context of coordination chemistry, the potassium ion coordinates with the L-asparagine, forming a stable structure where the central (metal) ion is surrounded by and associated with the L-asparagine, a ligand (complexing molecule), through coordinate covalent bonds.^[3][6][7]

Chemical properties

The composition by mass of elemental metal—potassium (K)—in potassium asparaginate (C₄H₇KN₂O₃) is approximately 23%, given that the molar mass of a potassium atom (K) is 39.1 grams per mole (g/mol), and the molar mass of a potassium asparaginate is 170.21 g/mol (39.1/170.21≈23%).^[2]

The solubility of potassium asparaginate, in g/100ml of various solvents (water, ethanol, methanol), at temperatures of 30, 35 and 40 degree Celsius, is the following:^[1]

Solubility of Potassium Asparaginate (g/100ml)^[1]

Liquid	30°C	35°C	40°C
Water	16	22	28
Ethanol	12	16	20
Methanol	11	15	19

Synthesis

Potassium asparaginate can be obtained from L-asparagine and potassium fluoride (KF) in a chemical reaction which yields potassium asparaginate and hydrofluoric acid (HF).^[1]

Applications

Medicine

Potassium asparaginate, along with magnesium asparaginate, is marketed in Russia and Eastern European countries to treat or prevent potassium deficiency (hypokalemia) and magnesium deficiency (hypomagnesemia).^[8][9] Potassium asparaginate and magnesium asparaginate purportedly improve metabolism in the myocardium (heart muscle), enhance the tolerance of cardiac glycosides (heart medications) and exhibit antiarrhythmic activity (help regulate heart rhythm).^[9][10] Still, these health claims are not backed up by reliable studies.^[11] In the United States, potassium asparaginate is not specifically approved by the Food and Drug Administration (FDA) for treating any medical condition;^[11] to treat hypokalemia, potassium is instead administered as other salts, namely, gluconate, citrate, chloride or bicarbonate.^[11]

Nonlinear optics

In nonlinear optics, crystals of potassium asparaginate are investigated as a potential nonlinear optical material, as salts of some amino acids possess strong nonlinear optical properties.^[1][12] A nonlinear optics material is a substance with high optical nonlinearity. Such substances are useful in applications such as signal transmission, data storage, or optical switching.^[1][12] High optical nonlinearity refers to the property of materials to respond to light (e.g., a laser) in a nonlinear manner, meaning that the property doesn't scale linearly with the intensity of the light applied.^[1][13]

See also

• Potassium aspartate
• Magnesium aspartate
• Magnesium asparaginate