AMIDES. 217 



The amides are widely distributed in the vegetable kingdom, 

 being found in especially large quantities in immature plants. 



The most important bodies classed as amides occurring in 

 plants are : 



1. Asparagine, which is really amido-succinamic acid, 



rr^o ~NT TT 

 C 2 H 8 (NH 2 )j QO OH* * S ^ oun( ^ m tne J u ^ ce f tne asparagus, in 



many fruits, roots, and tubers, in the young shoots of vetches, 

 beans, peas, &c. Asparagine crystallizes with one molecule of 

 water in prisms. It has a cooling, unpleasant taste, and 

 is soluble in about 80 parts of water. By boiling with 

 alkalies or other bases aspartic acid or amido-succinic acid, 

 C 2 H 3 (NH 2 )(COOH) 2 , is formed, with evolution of ammonia. 



Dilute hydrochloric acid produces the same acid and am- 

 monium chloride, the nitrogen of the amide ( CONH 2 ) group 

 being converted into ammonia. This is a general reaction 

 with amides. 



2. Glutamine, amido-glutamic acid, NH 2 .CO.C 8 H. 5 (NH 2 ). 

 COOH, is found in beetroot, the shoots of the vetch, and in the 

 pumpkin. It crystallizes in slender white needles, which con- 

 tain no water of crystallization. It is very soluble in hot 

 water, but insoluble in absolute alcohol. 



3. Choline, hydvoxyethyl-trimethyl-ammonium hydroxide, 

 C 2 H 4 (OH).N(CII S ) 8 .OH, occurs in cotton seed, in beets, in 

 hops, and in many other plants. It is a syrupy liquid with a 

 strong alkaline reaction. It appears to possess poisonous pro- 

 perties, which are sometimes apparent when cotton seed is 

 used as a food for very young animals. It forms a charac- 

 teristic reddish yellow crystalline compound with platinum 

 tetrachloride, (C 5 H 14 ON) 2 PtCl (i . 



4. Bctaine, trimethlyl glycocoll, is said to have the com- 

 position 



CH 2 



CO N(CH.) 8 



. 



It is found in beet juice, in mangolds, and in cotton seed. 

 It is formed by the oxidation of choline. It crystallizes with 

 one molecule of water. 



