Chemistry. — "Injiuence of dijfeirnt compounds on the destruction 

 of monosaccharids by so diumhydr oxide and on the inversion 

 of sucrose hy hydrochloric acid. Con stitutio?i-f or inula, of 

 a-amino-acids and of detain". By Dr. H. 1. Waterman. (Com- 

 municated by Prof. J. Böeseken). 



(Communicated in the meeting of April 27, 1917). 



The destruction of monosaccharids, such as glucose, galactose etc., 

 by basic substances, is accompanied by a decrease of polarisation 

 of the solution in question whilst at the same time the colour 

 becomes brown. 



The action of hydroxylions is measured by the rapidity of dimi- 

 nution of polarisation and by the colour-intensity of the solution. 

 I have noticed that different substances belonging to a series of 

 compounds which generally have no or only a slightlj' acidic cha- 

 racter, for instance amino acetic acid and «-aminopropionic acid, are 

 able to neutralize the destructive action on glucose of considerable 

 concentrations of alkali ^). 



In order to increase the general importance of my observations 

 I have repeated the experiments with solutions of galactose instead 

 of glucose. The results obtained are quite the same as with glucose 

 (See table T). The action of hydroxylions on galactose is retarded 

 too by different "neutral" substances. Whereas the addition of 

 5 cm'. 1,06 normal NaOH-solution in the experiments mentioned 

 in table I after three hours has lowered polarisation from -|- 12,4 

 to 4- 9,3 and -|- 9,4, in the presence of 500 milligrams of alanin 

 the same concentration of alkali has lowered polarisation only to 

 -|- 11,1. After 24 hours and especially after 48 hours the pheno- 

 menon could be observed much better still. So, after 48 hours, 

 without the addition of alanin the polarisation had diminished from 

 12,4 to 4,0 respectively 4,3; in the presence of alanine the polari- 

 sation had only diminished to 9,7. 



The difference in colour-intensity of the solutions examined was 

 in accordance with these facts. After ± 48 hours, in presence of 

 sodium hydroxide, but without alanine, the colour was brown yellow, 

 with alanine only pale-yellow. 



^) H. I. Waterman, Chemisch Weekblad 10, 739 (1913); 14, H9 (1917}. 



