54 W. G. OVEREND AND M. STAGEY 



ommended procedure, the material is heated at 100° for 10 minutes with 

 tryptophane and 30% (final concentration) perchloric acid, and in a 

 positive test there is a rapid development of a red color. Quantitative es- 

 timations can be carried out by measuring the intensity of the color de- 

 veloped in a photoelectric colorimeter with filters having a transmission 

 range of 485-550 m/x. 



The intensities of the colors produced by normal hexoses and pentoses 

 and their 2-deoxy-analogues w^ith Schiff's reagent^^^ have been measured 

 quantitatively^^^ with strict control of temperature and air contamination. 

 It was found that 2-deoxyribose gave a much more intense color than 

 ribose under comparable conditions. Gurin and Hood^^® have demon- 

 strated that addition of a solution of carbazole to an ice-cold mixture of 

 sulfuric acid and 2-deoxyribose results in the formation of an intense yellow 

 color. This test, however, is not as suitable as the diphenylamine reaction 

 for the detection and estimation of 2-deoxyribose and is markedly un- 

 specific. The reaction of cysteine and sulfuric acid-^^ with 2-deoxyribose 

 has also been used for estimation purposes. [Cf. Dische, Chapter 9.] Only 

 aldehydes with an a-methylene group (i.e., R — CH2CHO) condense with 

 3 , 5-diaminobenzoic acid to form quinaldines.^^* Consequently, in the 

 carbohydrate series only 2-deoxysugars will react and hence they can be 

 differentiated from their normal parent sugars. Attempts have been made to 

 estimate 2-deoxyribose by the orcinol reaction for pentoses, but in the test 

 the deoxysugar is mainly converted into levulinic acid which gives no 

 color wdth the reagent. The Dreywood^^^ anthrone reagent, w^hich gives a 

 positive qualitative test for a large variety of carbohydrates, gives a nega- 

 tive test for 2-deoxyribose.^''^ 



Recently, color tests have been found by which deoxysugars may be 

 distinguished from other sugars or sugar derivatives on paper chromato- 

 grams.'''* Partridge'" has reported Rp values (corrected to 20°) of 2-deoxy- 

 D-ribose on Whatman No. 1 filter paper in various solvents. These were 

 as follows: 



Solvent Phenol containing s-Collidine Isobutyric acid 



NH3(l%wt./vol.):HCX 

 /2f value 0.73 0.60 0.32 



23" H. Schiff, Ann. 140, 102 (1866). 



298 W. G. Overend, J. Chem. Soc. 1950, 2769. 



296 S. Gurin and Dorothy B. Hood, J. Biol. Chem. 131, 211 (1939); 139, 775 (1941). 



2" Z. Dische, Proc. Soc. Exptl. Biol. Med. 55, 217 (1944). 



298 L. Vellu, M. Pesez, and G. Amiard, Bull. soc. chim. France 15, 680 (1948). 



299 R. Dreywood, Ind. Eng. Chem., A7ial. Ed. 18, 499 (1946). 



SO" L. Sattler and F. W. Zerban, /. Am. Chem. Soc. 72, 3814 (1950). 



">• J. T. Edward and Deirdre M. Waldron, /. Chem. Soc. 1952, 3631. 



