L-Cystein

Description

L-Cystein · CAS 52-90-4 · C3H7NO2S. UNII K848JZ4886. Melting Point: 240; Melting Point: 260 °C decomposes; Melting Point: 220 °C.

Identification

CAS Registry Number	52-90-4
PubChem CID	5862
Molecular formula	C3H7NO2S
IUPAC name	(2R)-2-amino-3-sulfanylpropanoic acid
UNII (FDA)	K848JZ4886
FEMA number	3263
JECFA number	1419

Computed Descriptors

Molecular Weight	121.16
XLogP3	-2.5
Hydrogen Bond Donor Count	3
Hydrogen Bond Acceptor Count	4
Rotatable Bond Count	2
Exact Mass	121.01974964
Monoisotopic Mass	121.01974964
Topological Polar Surface Area	64.3
Heavy Atom Count	7
Formal Charge	0

Physical & Chemical Properties

Melting Point	240
Melting Point	260 °C decomposes
Melting Point	220 °C
Solubility	277000
Solubility	277 mg/mL at 25 °C
Vapor Pressure	0.00000207 [mmHg]
LogP	-2.49
LogP	log Kow = -2.49
Ionization Efficiency	1.24
Ionization Efficiency	2.7

Physical description & handling notes

• Colorless or white solid; [HSDB] Colorless crystalline solid; [Sigma-Aldrich MSDS]
• Solid
• White crystals; Sulferous aroma
• Colorless crystals
• White crystals
• Freely soluble in water

Regulatory Status

Regulatory & Food Contact	EU Flavoring substances FDA Substance added to food: DOUGH STRENGTHENER, FLAVOR ENHANCER, FLAVORING AGENT OR ADJUVANT, FLOUR TREATING Flavoring Agents FLAVOURING_AGENT: Flavouring Agent Savory DOUGH STRENGTHENER, FLAVOR ENHANCER, FLAVORING AGENT OR ADJUVANT, FLOUR TREATING AGENT, NUTRIENT SUPPLEMENT
GHS notification summary	33.8% (179 / 529)

GHS Hazard Classification

GHS notification summary	33.8% (179 / 529)
Reported hazard statements	H302 (55.6%), H315 (11.9%), H319 (11.9%), H335 (11.9%)

Documented Uses

• Cysteine is a non-essential amino acid that has been used as a dough conditioner and veterinary detoxicant; [Merck Index] Used as a flavoring agent, dough strengthener, nutritional supplement, and flour treating agent for foods; [FDA] Used for biochemical and nutritional research and as a medication; [HSDB]
• Table: Reported uses (ppm): (Flavor and Extract Manufacturers' Association, 1994) [Table#3867]
• Biochemical and nutrition research, reducing agent in bread doughs (up to 90 ppm).
• Treatment with cysteine reduced seedling injury caused by gamma-irradiation of sorghum seed. Cysteine effects were most pronounced in primary root elongation.
• Use (kg) in Switzerland (2009): >10000
• Use (kg; approx.) in Germany (2009): >100000

Synonyms

L-cysteine; 52-90-4; cysteine; Cystein; (R)-2-Amino-3-mercaptopropanoic acid; Thioserine; Half-cystine; L-(+)-Cysteine; beta-Mercaptoalanine; L-Cystein; (2R)-2-amino-3-sulfanylpropanoic acid; Cysteinum; L-Cys; cisteina; Half cystine; 2-Amino-3-mercaptopropionic acid

Frequently Asked Questions

What are the CAS number and molecular formula of L-Cystein?

CAS 52-90-4; molecular formula C3H7NO2S; molecular weight — g/mol.

What other names is L-Cystein known by?

L-cysteine, 52-90-4, cysteine, Cystein, (R)-2-Amino-3-mercaptopropanoic acid, Thioserine.

What is the regulatory status of L-Cystein?

Documented regulatory listings: EU Flavoring substances; FDA Substance added to food: DOUGH STRENGTHENER, FLAVOR ENHANCER, FLAVORING AGENT OR ADJUVANT, FLOUR TREATING; Flavoring Agents.

Is L-Cystein classified as hazardous?

33.8% of GHS notifications report no hazard classification (179 of 529).

What are the key physical properties of L-Cystein?

Melting Point: 240; Melting Point: 260 °C decomposes; Melting Point: 220 °C; Solubility: 277000.

Facts on this page are taken from PubChem (US National Library of Medicine) and Wikidata. Grade-specific data — assay, moisture, particle size, packaging, shelf life — is issued per batch on the COA and is not published here.