N-Tagatose

The aldose-ketose mixtures have usually been separated by oxidiaing the aldoses with hypobromite. Occasionally, an aldose has been removed by fermentation— as in the isolation of n-tagatose from a n-tagatose-D-galactose mixture. Levene and Tipson separated the mixtures from the respective transformations of n-xylose and of L-arabinose by forming and fractionally distilling the isopropylidene derivatives. 

An investigation of the unidentified carbonyl compounds resulting from the other n-fructose moiety of (56) showed that the preponderant component was 3-deoxy-D-erj/< TO-hexo8ulose (52). Similarly di-n-tagatose-glycine formed 3-deoxy-n-[Pg.255]

Occurrence 99), n-Tagatose has been obtained as a hydrolytic product from a gum exudate of the tropical tree Sterculia setigera ),... 

Bissett, D. L. and Anderson, R. L. 1974B. Lactose and D-galactose metabolism in Group N streptococci Presence of enzymes for both the D-glactose 1-phosphate and d-tagatose 6-phosphate pathways. J. Bacteriol 117, 318-320. 

Another transformation of n-galactose to calcium n-altronate has been carried out by Reichstein and Bosshard. They heated 100 g. of D-galactose (LXXI) in anhydrous pyridine for five hours to effect partial rearrangement. From the mixture, they recovered 80 g. of crystalline D-galactose, removed the rest of it by fermentation, and obtained finally about 6.5 g. of pure D-tagatose (LXXII). This ketose formed a crystalline diisopropylidene derivative (LXXIII) which could be oxidized by alkaline permanganate to diisopropylidene-D-tagaturonic acid (LXXIV). 

From 3,6-Anhydromonosaccharide OsotriazdlesA —The osotriazoles of the 3,6-anhydro derivatives of D-psicose and L-tagatose gave the same dialdehyde monohydrate, to which the hemialdal structure (33) was assigned. The mirror-image product (34) was obtained from oxidation of the HC=N... 

Deoxy-D-well studied as the o-erythro isomer. It has been prepared in two ways from the decomposition of l,l -(carboxymethylamino)bis(l-deoxy-D-tagatose), ( di-D-tagatosegly-cine ), and from iV-butyl-D-galactosylamine. " These two methods and the isolation procedures are similar to the corresponding ones described for the erythro isomer. The 3-deoxy-n-i/ireo-hexosulose (42) was obtained as a colorless, amorphous powder, [ ]d + 10° — + 12.7° (in water), and was characterized as osazones. The (2,5-dichlorophenyl)osazone and the (2,4-dinitrophenyl)osazone are crystalline, the latter yielding a triacetate. " ... 

Preparative chromatography. A soln. of D-tagatose in aq. NHg-n-propanol adsorbed on silica gel-H (E. Merck, Darmstadt), left 12 hrs. on the column, and... 

Hall, D. R., Bond, C. S., Leonard, G. A., Watt, I., Berry, A., and Himter, W. N., Structure of tagatose-l,6-bisphosphate aldolase— Insight into chiral discrimination, mechanism, and specificity of class II aldolases. /. Biol. Chem. 2002, 277 (24), 22018-22024. 

---