Dimethyl dicarbonate

Dimethyl dicarbonate
Dimethyl dicarbonate
General
Systematic name	methoxycarbonyl methyl carbonate
Other names	DMDC dicarbonic acid dimethyl ester dimethyl pyrocarbonate Velcorin®
Molecular formula	C4H6O5
SMILES	O=C(OC(=O)OC)OC
Molar mass	134.09 g·mol−1
Appearance	Colourless liquid
CAS number	4525-33-1
Properties
Density and phase	1.25 g/ml, liquid
Solubility in water	3.4 g/100 ml (20 °C)
Melting point	16-18°C
Boiling point	172°C
Viscosity	2.1 Pa.s at 20 °C
Hazards
MSDS	External MSDS
Main hazards	Toxic
R-phrases	22-23-34
S-phrases	S7/9, S26, S36/37/39, S45
Flash point	85°C
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Dimethyl dicarbonate or DMDC is a colourless liquid with a sharp odour. Its primary use is as a beverage preservative or sterilant (INS No. 242), and acts by inhibiting the enzymes acetate kinase and L-glutamic acid decarboxylase [1]. It has also been proposed that methoxycarbonylation of the histidine part of the enzymes alcohol dehydrogenase and glyceraldehyde 3-phosphate dehydrogenase by DMDC inhibits these essential enzymes also [2]. Once it has been added to beverages, the efficacy of the chemical is provided by the following reactions:

• DMDC + H₂O → 2CH₃OH + 2CO₂
• DMDC + ROH → Ethyl methyl carbonate
• DMDC + NH₃ → Methyl carbamate
• DMDC + Amino acid → Derived carboxymethyl

DMDC is sometimes used as a preservative in wine as a replacement to sulfur dioxide, inactivating wine spoilage yeasts such as Brettanomyces. In the U.S. the FDA approved its use in wines in 1998, with the maximum permitted level being set at 200mg/L, and only if there was less than 500 yeast cells/mL at time of dosage. Usage has also been approved in Germany (since 1978) and New Zealand. The application of DMDC is particularly useful when wine needs to be sterilised but cannot be sterile filtered, pasteurized, or sulfured.

DMDC has also been used to sterilise coffee, tea, cider, fruit wine and mead.

External links

• Dimethyl dicarbonate at EPA SRS
• Dimethyl dicarbonate technical data at Panreac
• Dimethyl dicarbonate technical data at FAO
• Dimethyl dicarbonate and microbiological stabilityde:Dimethyldicarbonat