Phosphorylthiocholine

any of the phosphorylated analogues of acetylcholine having the structural formula

where R, R’, R” represent alkyls. Water-soluble crystalline substances, phosphorylthiocholines also include compounds containing a tertiary atom of nitrogen, seen in the structural formula

These compounds are high-boiling liquids that have limited solubility in water and good solubility in certain organic solvents; they are hardly saponified at all with water. Phosphorylthiocholines containing a tertiary nitrogen can be obtained through the following reaction:

Phosphorylthiocholines are powerful war gases, inducing neuroparalysis. Compounds containing a tertiary nitrogen are known as V gases. These compounds, in contrast to the other phosphorylthiocholines, have a high skin absorptive toxicity; a dose of 8–10 mg is fatal. The toxicity of compounds not possessing a tertiary nitrogen derives from the structural similarity of these compounds to the mediator acetylcholine, a similarity that allows the compounds to interact with and block the active sites of the enzyme cholinesterase. Compounds possessing the tertiary nitrogen are apparently transformed within the body into their counterparts without this nitrogen; they then act in analogous fashion. Gas masks and protective clothing provide defense against V gases, and antidotes are administered in the event of poisoning. Both types of phosphorylthiocholines react vigorously with chlorinating agents, a characteristic that is useful in degasification.