52-89-1
Product Name:
L-Cysteine monohydrochloride
Formula:
C3H8ClNO2S
Synonyms:
L -Cysteine hydrochloride monohydrate
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CHEMICAL AND PHYSICAL PROPERTIES
| Physical Description | Solid; [Sigma-Aldrich MSDS] |
|---|---|
| Color/Form | Colorless crystals |
| Melting Point | 260 °C decomposes |
| Solubility | Freely soluble in water |
| LogP | log Kow = -2.49 |
| Stability/Shelf Life | Stable under recommended storage conditions. |
| Optical Rotation | Decomposes 175-178 °C; soluble in water, alcohol, acetone; the aqueous solution is acid; decomposes and oxidizes slowly; hygroscopic. Specific optical rotation: +5.0 °C (5 N HCl) at 25 °C/D; +10.0 °C at 25 °C/D (glacial acetic acid) /Cysteine hydrochloride/ |
| Decomposition | When heated to decomposition it emits very toxic fumes of /sulfur oxides and nitrogen oxides/. |
| Ionization Efficiency | Positive |
| Dissociation Constants | pK1 1.71 /carboxylic/; pK2 8.33 /amine/; pK3 10.78 /sulfide/ |
| Other Experimental Properties | Readily oxidizes to form a dimeric amino acid, cystine, in which the two cysteines are linked via a disulfide bridge, a common structural feature in proteins. Amino Acids and Proteins, D.M. Greenberg, Ed. (Charles C. Thomas, Springfield, IL, 1951) 950 pp. |
| Chemical Classes | Biological Agents -> Amino Acids and Derivatives |
SAFETY INFORMATION
| Signal word | Warning |
|---|---|
| Pictogram(s) |
 Exclamation Mark Irritant GHS07 |
| GHS Hazard Statements |
H315:Skin corrosion/irritation H319:Serious eye damage/eye irritation H335:Specific target organ toxicity, single exposure;Respiratory tract irritation |
| Precautionary Statement Codes |
P261:Avoid breathing dust/fume/gas/mist/vapours/spray. P304+P340:IF INHALED: Remove victim to fresh air and Keep at rest in a position comfortable for breathing. P305+P351+P338:IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing. P405:Store locked up. |
COMPUTED DESCRIPTORS
| Molecular Weight | 157.62 g/mol |
|---|---|
| Hydrogen Bond Donor Count | 4 |
| Hydrogen Bond Acceptor Count | 4 |
| Rotatable Bond Count | 2 |
| Exact Mass | 156.9964274 g/mol |
| Monoisotopic Mass | 156.9964274 g/mol |
| Topological Polar Surface Area | 64.3 Ų |
| Heavy Atom Count | 8 |
| Formal Charge | 0 |
| Complexity | 75.3 |
| Isotope Atom Count | 0 |
| Defined Atom Stereocenter Count | 1 |
| Undefined Atom Stereocenter Count | 0 |
| Defined Bond Stereocenter Count | 0 |
| Undefined Bond Stereocenter Count | 0 |
| Covalently-Bonded Unit Count | 2 |
| Compound Is Canonicalized | Yes |
PRODUCT INTRODUCTION
description
L-cysteine hydrochloride is a hydrochloride obtained by combining L-cysteine with one molar equivalent of hydrogen chloride. It has a role as an EC 4.3.1.3 (histidine ammonia-lyase) inhibitor, a flour treatment agent and a human metabolite. It contains a L-cysteinium.