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Dimethyl dicarbonate

Dimethyl dicarbonate
Systematic name methoxycarbonyl methyl carbonate
Other names DMDC
dicarbonic acid
dimethyl ester
dimethyl pyrocarbonate
Molecular formula C4H6O5
Molar mass 134.09 g·mol−1
Appearance Colourless liquid
CAS number 4525-33-1
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
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.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Dimethyl_dicarbonate". A list of authors is available in Wikipedia.
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