Methyl methanesulfonate

Methyl methanesulfonate (MMS), also known as methyl mesylate, is an alkylating agent and a carcinogen. It is also a suspected reproductive toxicant, and may also be a skin/sense organ toxicant.^[1] It is used in cancer treatment.^[2] Its chemical formula is CH₃−SO₂−O−CH₃.

Methyl methanesulfonate

Skeletal formula
Ball-and-stick model
Names
Preferred IUPAC name Methyl methanesulfonate
Other names Methanesulfonic acid methyl ester Methyl mesylate MMS
Identifiers
CAS Number	66-27-3 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:25255 N
ChemSpider	4013 N
ECHA InfoCard	100.000.568
EC Number	200-625-0
KEGG	C19181 Y
MeSH	D008741
PubChem CID	4156
UNII	AT5C31J09G Y
CompTox Dashboard (EPA)	DTXSID7020845
InChI InChI=1S/C2H6O3S/c1-5-6(2,3)4/h1-2H3 N Key: MBABOKRGFJTBAE-UHFFFAOYSA-N N InChI=1/C2H6O3S/c1-5-6(2,3)4/h1-2H3 Key: MBABOKRGFJTBAE-UHFFFAOYAK
SMILES COS(=O)(=O)C
Properties
Chemical formula	CH3SO2OCH3
Molar mass	110.13 g·mol−1
Density	1.3 g/mL at 25 °C
Boiling point	202 to 203 °C (396 to 397 °F; 475 to 476 K)
Related compounds
Related compounds	Ethyl methanesulfonate Dimethyl sulfone Dimethyl sulfate S-Methyl methanethiosulfonate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Chemical reactions with DNA

MMS methylates DNA predominantly on N7-deoxyguanosine and N3-deoxyadenosine, and to a much lesser extent also methylates at other oxygen and nitrogen atoms in DNA bases, and also methylates one of the non-carbon bound oxygen atoms of the phosphodiester linkage. Originally, this action was believed to directly cause double-stranded DNA breaks, because homologous recombination-deficient cells are particularly vulnerable to the effects of MMS.^[3] However, it is now believed that MMS stalls replication forks, and cells that are homologous recombination-deficient have difficulty repairing the damaged replication forks.^[3]

See also

• Dimethyl sulfite, a chemical with the same molecular formula but different arrangement