Choline bitartrate

Choline bitartrate is an organic compound with the chemical formula [(CH₃)₃NCH₂CH₂OH]⁺HOOC−CH(OH)−CH(OH)−COO⁻. It is a white crystalline powder with an acid taste. It is hygroscopic when exposed to air. Modern texts refer to the choline salt of the natural form of tartaric acid, that is, the salt called choline dextrobitartrate, choline (2R,3R)-bitartrate or choline L-(+)-bitartrate.

Choline (2R,3R)-bitartrate

Names
IUPAC name Choline (2R,3R)-bitartrate
Systematic IUPAC name (2-Hydroxyethyl)trimethylaminium hydrogen (2R,3R)-tartrate
Other names Choline hydrogen L-(+)-tartrate Choline (2R,3R)-tartrate (1:1) (2-Hydroxyethyl)trimethylammonium hydrogen (2R,3R)-tartrate (2-Hydroxyethyl)trimethylammonium L-(+)-bitartrate (2-Hydroxyethyl)trimethylammonium (2R,3R)-bitartrate (2-Hydroxyethyl)trimethylammonium L-(+)-tartrate salt (1:1)
Identifiers
CAS Number	87-67-2
3D model (JSmol)	Non-isomeric: Interactive image Isomeric: Interactive image
ECHA InfoCard	100.001.604
PubChem CID	6900
UNII	6K2W7T9V6Y
CompTox Dashboard (EPA)	DTXSID00889332
InChI : InChI=1S/C5H14NO.C4H6O6/c1-6(2,3)4-5-7;5-1(3(7)8)2(6)4(9)10/h7H,4-5H2,1-3H3;1-2,5-6H,(H,7,8)(H,9,10)/q+1;/p-1/t;1-,2-/m.1/s1 Key: QWJSAWXRUVVRLH-LREBCSMRSA-M
SMILES Non-isomeric: C[N+](C)(C)CCO.C(C(C(=O)[O-])O)(C(=O)O)O Isomeric: C[N+](C)(C)CCO.[C@@H]([C@H](C(=O)[O-])O)(C(=O)O)O
Properties
Chemical formula	C9H19NO7
Molar mass	253.251 g·mol−1
Appearance	White crystalline powder
Odor	Odorless or faint trimethylamine-like odor
Melting point	147–153 °C (297–307 °F; 420–426 K)
Solubility	Water (slightly), ethanol (slightly), DMSO (slightly), methanol (slightly, when heated); insoluble in diethyl ether, chloroform and benzene
Structure
Coordination geometry	Tetrahedral molecular geometry at the nitrogen atom
Hazards
Lethal dose or concentration (LD, LC):
LD50 (median dose)	200 to 400 grams (as choline, human, estimated)
Related compounds
Other anions	Choline chloride Choline hydroxide
Other cations	N,N-Dimethylethanolamine bitartrate
Related compounds	Choline Ethanolamine Tartaric acid Trimethylamine
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Chemistry

Choline bitartrate is a choline salt of tartaric acid. Choline bitartrate contains quaternary ammonium cations ((2-hydroxyethyl)trimethylammonium [(CH₃)₃NCH₂CH₂OH]⁺) and bitartrate anions (HOOC−CH(OH)−CH(OH)−COO⁻). Quaternary ammonium cation is a cation in which all four hydrogen atoms of ammonium are replaced with organyl groups. In the choline cation, the four substituents of ammonium are three methyl groups (−CH₃) and one 2-hydroxyethyl group (−CH₂CH₂OH). The bitartrate anion is chiral (there are left, right and meso forms of bitartrate, see tartaric acid).

Production

Choline bitartrate can be produced by the chemical reaction of trimethylamine with ethylene oxide and water, followed by reaction with tartaric acid.

N(CH₃)₃ + CH₂CH₂O + H₂O → [(CH₃)₃NCH₂CH₂OH]⁺OH⁻ [(CH₃)₃NCH₂CH₂OH]⁺OH⁻ + C₄H₆O₆ → [(CH₃)₃NCH₂CH₂OH]⁺C₄H₅O−6 + H₂O

Uses

Choline bitartrate is used as a dietary supplement, a food additive, a nutrient and as a lipotropic compound. It is also used as a medication against bipolar disorder and mania (see: choline). Certain conducted double-blind, placebo-controlled studies of the effects of choline bitartrate treatment against Alzheimer-type dementias suggest improvement in some areas of patients' cognitive performance.

Safety

Choline bitartrate is flammable. When burned, choline bitartrate may release toxic gases, like carbon monoxide (CO), carbon dioxide (CO₂) and nitrogen oxides (NO, NO₂). May react violently with strong oxidizing agents.

The toxicity of this compound is similar to toxicity of choline itself, which is fairly low, and it is used as a dietary supplement. Oral LD₅₀ value for a human is estimated to be 200 to 400 grams (as choline). Nevertheless, choline bitartrate can be harmful, if absorbed through skin. It may cause skin, eye and respiratory system irritation. May cause gastrointestinal system irritation as well. If swallowed in high doses, may cause dizziness, nausea, vomiting and diarrhea, and a rotten fish-like body smell resulting from the excretion of trimethylamine from the body (trimethylamine is a choline metabolite). There are reports of depression or increased symptoms of it in patients using high doses of choline bitartrate. When choline bitartrate is used appropriately, hazardous effects are unlikely to occur.