DERIVATIVES. 201 



of sugars from another class, namely, the preparation of sugars poor in 

 carbon from those rich in carbon, for example, pentoses from hexoses 

 (see WOHL). 



According to RUFF, by the action of hydrogen peroxide and the cata- 

 lytic action of ferric salts upon the carbohydrate monocarboxylic acids 

 the carbon chain can be shortened by the splitting off of the elements 

 of formic acid, and with the formation of the next lower aldose. NEU- 

 BERG 1 has accomplished the same result by electrolysis, and by this 

 method has split glucose step by step into formaldehyde. 



By the action of alkalies, even in small amounts, as also of carbonates 

 and lead hydroxide, a reciprocal transformation of the sugars, such as 

 d-glucose, d-fructose, and d-mannose, may take place (LOBBY DE BRUYN 

 and ALBERDA VAN EKENSTEiN 2 ), and from each of these three varieties 

 of sugar the two others are produced so that after a certain time the 

 solution contains all three sugars. 



The transformation of the different varieties of sugar into each other 

 also occurs in the animal body. NEUBERG and MAYER 3 have shown by 

 experiments on rabbits the direct partial transformation of various 

 mannoses into the corresponding glucoses. Another example is, it 

 seems, the formation of galactose (or milk sugar) from glucose in the 

 mammary gland. 



By the action of strong alkali the sugars are decomposed with the 

 formation of lactic acid and many other products. 



With ammonia the glucoses may form compounds which have been 

 considered as osamines by LOBRY DE BRUYN, but to differentiate them 

 from the true osamines have been called osimines by E. FISCHER.* The 

 corresponding osaminic acid can be obtained from such an osimine by 

 the action of ammonia and hydrocyanic acid, and from the hydrochloric- 

 acid lactone of this acid the osamine is obtained by reduction with sodium 

 amalgam. In this manner E. FISCHER and LEUCHS artificially prepared 

 first d-arabinosimine from d-arabinose, then d-glucosaminic acid and 

 finally from its lactone d-glucosamine, which occurs in the animal 

 body. In a similar manner they 5 obtained Z-glueosamine from 

 Z-arabinose. 



KNOOP and WIND AT: s 6 have obtained large amounts of methylimida- 



1 Ruff, Ber. d. d. chem. Gesellsch., 31 and 32; Neuberg, Biochem. Zeitschr., 7. 

 2 Ber. d. d. chem. Gesellsch., 28, 3078; Bull. soc. chim. de Paris (3), 15; Chem. 

 Centralbl., 1896, 2, and 1897, 2. 



3 Zeitschr. f. physiol. Chem., 37. 



4 Lobry de Bruyn, Ber. d. d. chem. Gesellsch., 28; E. Fischer, ibid., 35. 



5 Ibid., 35, p. 3787, and 36, 24 (1903). 



6 Ibid., 38, and Hofmeister's Beitrage, 6. 



