Dische test

Fio, 1.—Curves for Light-absorption in the Dische Test (o) 2-Desoxy-D-ribose (61) D-Arabinal (i2) L-Arabinal (c) Furfuryl alcohol (d) w-Methoxylevulinaldehyde Dimethyl Acetal (e) Sodium Thymonucleate (/) Methyl 2-desoxy-/3-n-ribopyrano-side (g) Methyl 3,4-Dimethyl-2-desoxy-/3-L-ribopyranoside. 

A preliminary chemical investigation of the polysaccharides of M. tuberculosis has recently been undertaken by W. N. Haworth and the authors. It was found that two stable and probably degraded polysaccharide fractions could be isolated from the defatted cells by the action of sodium hydroxide. Both products were serologically active at a dilution of 1 2,000,000 the first fraction ([a] D + 85° in water) was derived mainly from the somatic portion of the cell, while the second + 27° in water) was found in the ether-soluble lipid constituents. Both fractions were intimately associated with deoxyribonucleic acid, which was identified by nitrogen and phosphorus analyses, by the Dische test and by spectrophotometric measurements. 

These considerations throw a new light on the Dische test for hexosa-mines, which is based on the formation of a furan ring on nitrous acid... 

Hexosamines, Dische test for, 49 Hexose, o-arabino-, (p-bromophenyl)-osazone, 5,6-dimethyl ether, 148 (A -methyl-JV -phenyl)osazone, 138, 141... 

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