while thio-seco-hemicholinium 3 ( 11 ) is stable in the presence of acetylcholinesterase and butyrylcholinesterase in h2o at ph 7.4 , acetylthio-seco-hemicholinium-3 ( 12 ) reacts within seconds to form the hemiacetal form of thiohemicholinium-3 ( 16 ) .
C0001044
acetylcholinesterase
C0008429
butyrylcholinesterase