| |||
| Names | |||
|---|---|---|---|
| Preferred IUPAC name Methanesulfonyl fluoride[1] | |||
| Other names Fumette, Mesyl fluoride | |||
| Identifiers | |||
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3D model (JSmol) | |||
| Abbreviations | MSF | ||
| ChemSpider | |||
| ECHA InfoCard | 100.008.358 | ||
| EC Number |
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| MeSH | methanesulfonyl+fluoride | ||
| RTECS number |
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| UNII | |||
| UN number | UN3389 | ||
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| Properties | |||
| CH3FO2S | |||
| Molar mass | 98.09 g·mol−1 | ||
| Appearance | liquid | ||
| Odor | pungent | ||
| Density | 1.427 g/mL[3] | ||
| Boiling point | 123 to 124 °C (253 to 255 °F; 396 to 397 K)[3] | ||
| Reacts | |||
Refractive index (nD) | 1.360[2] | ||
| Hazards | |||
| Occupational safety and health (OHS/OSH): | |||
Main hazards | Corrosive Highly toxic | ||
| GHS labelling: | |||
  | |||
| H300,H314,H330 | |||
| P301+P310,P303+P361+P353,P304+P340,P305+P351+P338,P320,P330,P405,P501 | |||
| Related compounds | |||
Otheranions | Methanesulfonyl chloride | ||
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |||
Methanesulfonyl fluoride (MSF) has long been known to be a potentinhibitor ofacetylcholinesterase (AChE), theenzyme that regulatesacetylcholine, an important neurotransmitter in both thecentral andperipheral nervous systems.[4][5]
MSF is a clear, colorless to yellowishhygroscopic liquid (attracts and holds water by absorption or adsorption). It iscorrosive and highly toxic. It is anoxydiaphoric inhibitor (acid-transferring inhibitor)[6] of the enzymeacetylcholinesterase.[6][3] MSF, which is a liquid at room temperature, has a vapor pressure of 19.2 mmHg, slightly more volatile than water which has a vapor pressure of 18.8 mmHg at 21 °C. This vapor has anLCt50 (lethal concentration, 50% death rate in a given time) in rats of between 4 and 5 parts per million (ppm) during one hour of exposure or between 1 and 1.2 ppm during 7 hours of exposure. MSF produced no subtle biological effects from direct action of MSF independent of its ability to inhibit cholinesterase. Repeated exposures to 1/10 of the LCt50 did not produce overt systemic toxicity or significant pathology.[7] MSF can also cause severe skin burns and serious eye damage, if contact is made. It is alachrymator and its vapor causes tears in eyes.[8][2]
Methanesulfonyl fluoride has a pungent odor. It undergoes decomposition on heating to liberate additional toxic fumes offluorides andsulfur oxides (SOx).[9]
A typical synthesis is to treatmethanesulfonyl chloride withpotassium fluoride orpotassium bifluoride in water and then steam distill the product out.[10]
Animal studies have shown that MSF-induced inhibition of AChE is highly selective for the brain when it is studied in vivo. MSF is an irreversible inhibitor of AChE and its inhibition of AChE is only overcome by de novo synthesis of new AChE in each tissue. The recovery of AChE activity in the brain is less than one-tenth as rapid as AChE recovery in the gastrointestinal system, allowing very high accumulated AChE inhibition in the brain with clinically insignificant AChE inhibition in peripheral tissues.[11][12] The high selectivity of MSF for inhibition in the brain has suggested that it could be used as a treatment for dementia of the Alzheimer type,[11] that it is effective in reducing the persistent cognitive deficit after stroke,[13] and it is highly effective in reducing normal age-related memory impairment, making aged rats perform as well as younger rats.[14]
Methanesulfonyl fluoride has been tested successfully in three human clinical trials as a treatment for Alzheimer's dementia. Two Phase I clinical trials testing for safety of MSF in humans at the doses proposed for treating dementia have shown that it is well tolerated and relatively free of the side effects of nausea, vomiting, and diarrhea that are produced by the current cholinesterase inhibitors used for the treatment of Alzheimer's dementia.[15] Furthermore, a Phase II, clinical trial testing both the safety and the efficacy of MSF found that it was well tolerated in the aged patients, and it was highly effective in reducing the symptoms of Alzheimer's dementia.[15] US Patent has been issued for the use of MSF for the treatment of dementia.[16]
