DIOSES AX I) TRIOSES 653 



unchanged diose appears in the urine after the first few minutes of injection 

 (author). P. Mayer reported glycosuria and death following administration of 

 impure glycollic aldehyde to rabbits. Parnas and Haer saw an increase of glycogen 

 in tortoise livers perfused with glycollic aldehyde. This is confircd by Harren- 

 scheen. Smedley noted the rapid disappear;ince of diose added to liver emulsions. 

 Sansum and Woodyatt, and also Greenwald obscr\-ed slight increases of the 

 glycosuria following parenteral administrations of diose in phlorhizinized but not 

 completely dcglycogenized dogs. The e.xtra sugar could have come from glycogen 

 in these experiments. A final proof of the conversion of diose into glucose in the 

 living body has not been brought. The relationship of this substance to glycine, 

 CH2NH2-COOH; glycoUic acid, CH2OH-COOH; and ethyl alcohol, CH,-CH,OH; 

 is close. Lusk states that glycine is capable of conversion into glucose in the body. 

 However, glycollic acid and alcohol are apparently not sugar formers. 



TRIOSES'* 



There are three possible trioses, d- and 1-glyceric aldehyde and the ketotriose 

 dihydroxyacetone. The optically inactive d, 1-glyceric aldehyde has been prepared 

 and recently the d- and l-forms. The preparation is still tedious and expensive. 

 Dihydroxy-acetone is somewhat easier to prepare. Both trioses are unstable, 

 easily oxidized and very prone to undergo rearrangements and condensation with 

 even traces of alkali. Under the influence of alkali they yield complex mixtures of 

 hexoses, chiefly 3-ketohexoses, formerly known as a and ^-acrose from which 

 Schmitzi* has recently isolated d,l-fructose and d,l-sorbose. If o.xygen is avail- 

 able as well as alkali, they burn. If the alkali is strong and oxygen lacking, much 

 lactic acid is formed together with certain rearranged tetrose, pentose and hexose 

 molecules, known as saccharinic acids (or "saccharines," of Iviliani). The same 

 phenomena occur when the alkali is dilute, but more slowlj'. The structural 

 formulae of the trioses and their relationship to glycerol, glyceric acid and lactic 

 acids (the latter of which might be regarded as a 3-carbon saccharinic acid) may 

 be seen from the following chart: 



H ] H H H OH OH OH 



' I ^ I I 



H— C— OH C=0 C=0 H— C— OH C^O C=0 C^O 



I I i I 



H— C— OHH— C— OHHO— C— H C O H— C— OH H— C— OH HO— C— H 



j 



H— C— OH H— C— OH H— C— OH H— C— OH H— C— OH H— C— H H— C— H 



II • . 



H H H H H 



1-glyceric dihydrosy d-glyceric d-lactic acid. I-lactic acid. 



aldehyde acetone acid 



(aldose) (ketose) 3-carbon saccharinic 



acid 



Neuberg fed animals and men considerable doses of impure d.l- 

 glyceric aldehyde (glycerose) and saw its apparently complete util- 

 ization. Parnas demonstrated increased glycogen in tortoise livers 

 perfused with d,l-glyceric aldehyde. Smedley noted the rapid chs- 

 appearance of glyceric aldehyde added to liver emulsions. Sansum 

 and Woodyatt fed pure crystalline d,l-glyceric aldehyde to rabbits 

 and guinea pigs in doses as high as 2.8 gm. per kg. with no apparent 

 ill effects. A dose of 5 gm. per kg. in a rabbit caused diarrhea with 



" Literature on Trioses: The chemical literature is reviewed and an improved 

 method of preparing glvceric aldehyde described by Witzemann, E. J., Jour. Am. 

 Chem. Soc, 1914 (36)", 1908, and ibid., p. 2223. The biological literature is 

 reviewed by Sansum, W. D. and Woodyatt, R. T., Jour. Biol. Chem.. 1916 (24), 

 327. 



i^Ber. Deut. Chem. Ges., 1914 (46), 2327. 



