310 CHEMISTRY OF THE PTOMAINS. 



action is antagonized by subsequent injection of atropin. In the 

 case of previously atropinized frogs it fails to antagonize. Very 

 small doses produced in rabbits profuse salivation and lachrymation, 

 contraction of the pupil, profuse diarrhea, and passage of urine and 

 semen ; finally, the animal died in convulsions, which, however, were 

 only of short duration (Brieger). Although the natural and artificial 

 muscarin and their salts are chemically and physically alike, they 

 are not however identical, although so considered by Schmiedeberg 

 and Harnack. This is seen in their physiological action. Thus 

 Bohm found that the artificial muscarin paralyzed intramuscular 

 nerve endings. According to Meyer, -^^ — -^-j^ mg. will do this, 

 whereas the natural base will not have this effect. Again, 1—2 

 drops of a 1 per cent, solution of the artificial base will produce 

 maximal myosis in birds in a few minut«s ; while the natural base 

 has no effect on birds' pupils. The action of betain aldehyde and 

 iso-muscarin has already been stated. Brieger's ptomain would seem 

 to be nearly identical with artificial muscarin. 



Constitution of the Members of the Cholin Group. — The struc- 

 ture of cholin was clearly demonstrated by Wurtz, who accomplished 

 the sjmthesis of this base by treatment of ethylene chlorhydrin with 

 trimethylamin. This same method can be applied to the synthesis 

 of betain and neurin by using monochloracetic acid and vinylbromid 

 instead of ethylene chlorhydrin. The structural formulae which can 

 be deduced from these reactions are as follows : 



,H 



N(CH,)3.0H S(CH3),.OH N(CH3),.0H 

 Cholin. NBrBiN. Bstaih. 



All these bases, since they can be prepared from cholin, may also 

 be considered as oxidation products of trimethyl-ethyl-ammonium 

 hydrate : 



N(CH,)8.0H. 



The constitution of muscarin is still unsettled. Schmiedeberg 

 and Harnack believed that it resulted from cholin by the oxidation 

 of hydrogen connected with the same carbon as the hydroxyl group. 

 Its formula would be either (1) or (2), as given below. The former, 

 analogous to chloral would have the somewhat rare condition of two 

 hydroxyl groups attached to one carbon atom. The presence of 

 hydroxyl groups in muscarin cannot, however, be demonstrated with 

 acetic anhydrid, or benzoyl chlorid (Nothnagel). The second formula 

 is that of betain aldehyd. 



