242 COMPOUNDS AND REACTIONS OF LEUCINE. [BOOK II. 



leucine, dextro- and Isevo-gyrous isomers, which are produced under 

 the influence of high temperatures, and that the action of Penicillium 

 glaucum is the same in all these cases. 



Compounds Leucine forms crystalline compounds with sulphuric, 



of leucine with hydrochloric and nitric acids. The hydrochloric acid 

 other bodies. compound is represented by the formula 



C 6 H 13 N0 2 .HC1. 



Leucine forms two crystalline compounds with cupric oxide. 



1. The compound, already referred to, which is formed when solu- 

 tions of leucine are boiled with freshly precipitated cupric hydrate, 

 separates in the form of sparingly soluble light blue rhombic tables, 

 and has a composition represented by the formula Cu(C 6 H 12 N0 2 ) 2 . 1 



2. When to a boiling solution of leucine there is added a boiling 

 solution of cupric acetate, there separate deep blue shining crystals 

 containing between 25'25, and 26'91 per cent, of CuO, a percentage 

 which agrees best with the empirical formula 



7C 6 H 13 N0 2 



Reactions l. It has already been said that when leucine is 



heated to 17 C- it melts and volatilises unchanged. 

 If further heated it yields amylamine and C0 2 , the 

 odour of the former being distinctly recognizable. 



C 6 H U (NH 2 )0 2 C 5 H n (NH 2 ) + C0 2 . 



x _ __ s x. ___ _ 25 



Leucine. Amylamine. 



2. The crystalline structure of leucine aids greatly in its recog- 

 nition. It will be remembered that when separating from extracts 

 of animal organs it presents the appearance of nodules and spheres ; 

 that after being sublimed it occurs in the form of plates arranged in 

 rosettes (p. 239). 



3. When leucine is treated with nitric acid and is slowly 

 evaporated on a slip of platinum foil it yields an almost colourless 

 residue ; when one or two drops of solution of sodium hydrate are 

 added to the residue and a little heat is applied an oily globule is 

 formed which rolls upon the foil without wetting it (Scherer's 

 reaction). 



4. Some of the substance may be dissolved in boiling water and 

 treated with boiling solution of cupric acetate, when the crystalline 

 copper compound, already described, will form. 



1 Fr. Hofmeister, 'Zur Kenntniss der Amidosauren,' Maly's Jahresbericht, Vol. vn. 

 (1878), pp. 7880. 



a H. Kitthausen und A. Kreusler, ' Ueber Leucin ,' Journ. f. prakt. Chemie, 1871, 

 p. 307. 



