Stereoselectivity of enzymes involved in toxicity and detoxification of soman.

The fate of the four stereoisomers of soman [0-(1,2,2- trimethylpropyl )-methyl-fluoro phosphonate] has been studied a) in vivo in mouse blood and liver after IP injection of 0.75 X LD50 RC- and SC-soman respectively, and b) in vitro upon incubation with acetyl- und pseudocholinesterase, aliesterase and phosphorylphosphatase . The analytical method used is based on gas chromatography-mass spectrometry with deuterated internal standard. Most soman disappeared very rapidly from blood and liver. In liver, SCRP and RCRP , the two isomers that preferentially react with cholinesterase, could be detected. The level of SCRP , which was higher than that of RCRP , could be followed for 17-18 h. In blood only SCRP could be detected. The amounts found were fairly constant during the time period 2 min to 4h, and it could even be detected 17-18 h after soman administration.