PRODUCTS

MERCAPTOETHANOL

CAS Registry Number: 60-24-2
EC Number: 200-464-6
Molecular Formula: C2H6OS
Molecular Mass: 78.13
Preferred IUPAC name: 2-Sulfanylethan-1-ol

Mercaptoethanol (also β-mercaptoethanol, BME, 2BME, 2-ME or β-met) is the chemical compound with the formula HOCH2CH2SH.
ME or βME, as it is commonly abbreviated, is used to reduce disulfide bonds and can act as a biological antioxidant by scavenging hydroxyl radicals (amongst others).
Mercaptoethanol is widely used because the hydroxyl group confers solubility in water and lowers the volatility.
Due to its diminished vapor pressure, its odor, while unpleasant, is less objectionable than related thiols.

Production
2-Mercaptoethanol is manufactured industrially by the reaction of ethylene oxide with hydrogen sulfide. Thiodiglycol and various zeolites catalyze the reaction.

Reactions
2-Mercaptoethanol reacts with aldehydes and ketones to give the corresponding oxathiolanes.
This makes 2-mercaptoethanol useful as a protecting group, giving a derivative whose stability is between that of a dioxolane and a dithiolane.

Applications
Reducing proteins
Some proteins can be denatured by 2-mercaptoethanol, which cleaves the disulfide bonds that may form between thiol groups of cysteine residues. In the case of excess 2-mercaptoethanol, the following equilibrium is shifted to the right:
RS–SR + 2 HOCH2CH2SH ⇌ 2 RSH + HOCH2CH2S–SCH2CH2OH

Reaction scheme for the cleavage of disulfide bonds by 2-mercaptoethanol
By breaking the S-S bonds, both the tertiary structure and the quaternary structure of some proteins can be disrupted.
Because of its ability to disrupt the structure of proteins, it was used in the analysis of proteins, for instance, to ensure that a protein solution contains monomeric protein molecules, instead of disulfide linked dimers or higher order oligomers.
However, since 2-mercaptoethanol forms adducts with free cysteines and is somewhat more toxic, dithiothreitol (DTT) is generally more used especially in SDS-PAGE. DTT is also a more powerful reducing agent with a redox potential (at pH 7) of −0.33 V, compared to −0.26 V for 2-mercaptoethanol.

Mercaptoethanol is often used interchangeably with dithiothreitol (DTT) or the odorless tris(2-carboxyethyl)phosphine (TCEP) in biological applications.

Although 2-mercaptoethanol has a higher volatility than DTT, it is more stable: 2-mercaptoethanol's half-life is more than 100 hours at pH 6.5 and 4 hours at pH 8.5; DTT's half-life is 40 hours at pH 6.5 and 1.5 hours at pH 8.5.

Preventing protein oxidation
2-Mercaptoethanol and related reducing agents (e.g., DTT) are often included in enzymatic reactions to inhibit the oxidation of free sulfhydryl residues, and hence maintain protein activity.
Mercaptoethanol is often used in enzyme assays as a standard buffer component.

Denaturing ribonucleases
Mercaptoethanol is used in some RNA isolation procedures to eliminate ribonuclease released during cell lysis.
Numerous disulfide bonds make ribonucleases very stable enzymes, so 2-mercaptoethanol is used to reduce these disulfide bonds and irreversibly denature the proteins.
This prevents them from digesting the RNA during its extraction procedure.

Chemical formula: C2H6OS
Molar mass: 78.13 g·mol−1
Odor: Disagreeable, distinctive
Density: 1.114 g/cm3
Melting point: −100 °C
Boiling point: 157 °C
log P: -0.23
Vapor pressure: 0.76 hPa
Acidity (pKa): 9.643
Basicity (pKb): 4.354
Flash point: 68 °C
Molecular Weight: 78.14
XLogP3-AA: -0.2
Hydrogen Bond Donor Count: 2
Hydrogen Bond Acceptor Count: 2
Rotatable Bond Count: 1
Exact Mass: 78.01393598
Monoisotopic Mass: 78.01393598
Topological Polar Surface Area: 21.2 Å²
Heavy Atom Count: 4
Formal Charge: 0
Complexity: 10
Isotope Atom Count: 0
Defined Atom Stereocenter Count: 0
Undefined Atom Stereocenter Count: 0
Defined Bond Stereocenter Count: 0
Undefined Bond Stereocenter Count: 0
Covalently-Bonded Unit Count: 1
Compound Is Canonicalized: Yes

Mercaptoethanol (also known as beta-mercaptoethanol or BME) is a potent reducing agent used in cell culture media to prevent toxic levels of oxygen radicals.
2-Mercaptoethanol is not stable in solution, so most protocols require daily supplementation.
Gibco 2-Mercaptoethanol contains 2-mercaptoethanol at a concentration of 55 mM in Dulbecco's phosphate buffered saline (DPBS).

Mercaptoethanol can act as an enzyme reactivator in systems necessitating reduction for activation, and has been commonly used to reduce disulfide bonds in order to separate protein subunits for use in electrophoresis.
This product can also be used to form o-Phthalaldehyde-beta-mercaptoethanol (OPAME), a fluorogenic reagent shown to detect amino acids based on its reaction with primary amines.
More recently OPAME has been used to distinguish between ssDNA/dsDNA and even single base mismatches in the hybridization of DNA.

The addition of a reducing agent to an assay may be important to prevent the oxidation of cysteines in the proteins being studied and thus the formation of disulfides.
The most commonly used reducing agents are dithiothreitol (DTT), β-mercaptoethanol (β-ME) and tris(2-carboxyethyl)phosphine (TCEP).
2-mercaptoethanol or β-mercaptoethanol or BME is a chemical compound of the formula HOCH2CH2SH, a "hybrid" of ethylene glycol and ethanedithiol.
At room temperature it is a liquid with a foul-smelling odor.
The presence of the thiol -SH function makes 2-mercaptoethanol a reducing agent widely used in biochemistry to protect proteins against oxidation.
The denaturation of proteins requires the reduction of disulfide bridges, which are crucial for the tertiary or quaternary structure of certain proteins.
It is commonly used to reduce disulfide bridges present in proteins and can play a role as a biological antioxidant.
It is also used because of its hydroxyl group, which makes it miscible in water and reduces the volatility (and therefore the odor) of thiol.
2-Mercaptoethanol is a powerful reducing agent used in cell culture media to prevent toxic levels of oxygen radicals.

Mercaptoethanol, also known as Thioglycol, or simply just BME, is a highly toxic, lightly colored
(though sometimes colorless) liquid, that has a very strong, unpleasant odor.
Mercaptoethanol is commonly used as a reducing agent in protein related experiments.
Beta Mercaptoethanol poses considerable risks to humans and the environment and hence, special
precautions must be taken in both its use and disposal.

Mercaptoethanol is a small molecule.
Mercaptoethanol is the major active constituent of silymarin, a standardized extract of the milk thistle seeds, containing a mixture of flavonolignans consisting of beta Mercaptoethanol, isobeta Mercaptoethanol, silicristin, silidianin, and others.

Widespread uses by professional workers
Mercaptoethanol is used in the following products: pH regulators and water treatment products and laboratory chemicals.
Mercaptoethanol is used in the following areas: health services and scientific research and development. Other release to the environment of 2-mercaptoethanol is likely to occur from: indoor use (e.g. machine wash liquids/detergents, automotive care products, paints and coating or adhesives, fragrances and air fresheners).

Uses at industrial sites
Mercaptoethanol is used in the following products: pH regulators and water treatment products and Mercaptoethanol has an industrial use resulting in manufacture of another substance (use of intermediates).
Mercaptoethanol is used in the following areas: mining and formulation of mixtures and/or re-packaging.
Mercaptoethanol is used for the manufacture of: chemicals.
Release to the environment of Mercaptoethanol can occur from industrial use: as an intermediate step in further manufacturing of another substance (use of intermediates), in processing aids at industrial sites, as processing aid and as processing aid.

Mercaptoethanol is a widely used antioxidant in protein production and analysis.
As a reducing agent, mercaptoethanol has the ability to cleave disulfide bonds, thus disrupting the tertiary and the quaternary structures of proteins.
Mercaptoethanol is also included in enzyme solution to protect against catalytic site inactivation due to cysteine sulfhydryl oxidation or disulfide formation.

Mercaptoethanol is considered a toxicant, irritating the mucous membranes and respiratory tract, causing sore throat and abdominal pain, and potentially death if severe exposure occurs.
As a result, determination of residual mercaptoethanol in biopharmaceutical products becomes crucial for patient safety.

Synonms:
2-mercaptoethanol
Mercaptoethanol
60-24-2
Beta-Mercaptoethanol
Thioglycol
Ethanol, 2-mercapto-
2-Sulfanylethanol
2-Thioethanol
Thioethylene glycol
Thiomonoglycol
2-Hydroxyethanethiol
2-Hydroxyethyl mercaptan
2-Hydroxy-1-ethanethiol
Monothioglycol
2-Mercapto-1-ethanol
1-Ethanol-2-thiol
Hydroxyethyl mercaptan
Monothioethylene glycol
2-Mercaptoethyl alcohol
2-ME
Ethylene glycol, monothio-
1-Hydroxy-2-mercaptoethane
1-Mercapto-2-hydroxyethane
2-Hydroxyethylmercaptan
Emery 5791
USAF EK-4196
2-sulfanylethan-1-ol
.beta.-Mercaptoethanol
.beta.-Hydroxyethanethiol
NSC 3723
UNII-14R9K67URN
2-mercapto ethanol
MFCD00004890
.beta.-Hydroxyethylmercaptan
14R9K67URN
DTXSID4026343
betamercaptoethanol
Mercaptoetanol
Monothioethyleneglycol
2-Mercaptoethanol, 99%, pure
2-Mercaptoethanol, >=99.0%
beta-Hydroxyethanethiol
beta-Hydroxyethylmercaptan
CCRIS 2097
HSDB 5199
EINECS 200-464-6
UN2966
BRN 0773648
2mercaptoethanol
AI3-07710
b-mercaptoethanol
ethylene thioglycol
2-mercapto-ethanol
2-sulfanyl-ethanol
beta-sulfanylethanol
hydroxyethyl sulfide
mercaptoethyl alcohol
2-Sulfanylethanol #
2-hydroxy-ethanethiol
2-Hydroxyethanethiol;
2-mercaptoethan-1-ol
HSCH2CH2OH
[O]CCS
OCC[S]
WLN: SH2Q
EC 200-464-6
4-01-00-02428 (Beilstein Handbook Reference)
DivK1c_000784
BDBM7971
CHEMBL254951
HMS502H06
KBio1_000784
NSC3723
NINDS_000784
NSC-3723
Thioglycol [UN2966] [Poison]
ZINC8216595
STL482546
2-Mercaptoethanol, for electrophoresis
AKOS000118900
CCG-231050
DB03345
MCULE-2252943288
UN 2966
IDI1_000784
BP-21398
2-Mercaptoethanol, for synthesis, 99.0%
DS-014379
M0058
M1948
2341-EP2284157A1
2341-EP2295429A1
2344-EP2272972A1
2344-EP2272973A1
2344-EP2277872A1
2344-EP2305648A1
C00928
16605-EP2281563A1
16605-EP2316459A1
67670-EP2269996A1
67670-EP2272972A1
67670-EP2272973A1
67670-EP2277872A1
67670-EP2292597A1
67670-EP2295414A1
67670-EP2301627A1
67670-EP2305808A1
67670-EP2308839A1
67670-EP2377849A22-Mercaptoethanol, SAJ special grade, >=99.0%
A832651
Q411084
Q-200296
3-Pyridinecarbonitrile, 4-methyl-2,6-di-5-morpholinyl-
F0001-1577
2-Mercaptoethanol, for HPLC derivatization, >=99.0% (GC)