Sugars, deuterated

Mora-Gutierrez, A., Kumosinski, T.F., Farrell, Jr., H.M. (1997). Oxygen-17 nuclear magnetic resonance studies of bovine and caprine casein hydration and activity in deuterated sugar solutions. Journal of Agricultural and Food Chemistry, 45, 4545-4553. 

Isbell and co-workers have now developed a more convenient method for measuring the primary rate of enolization that does not involve a primary isotope effect (25). The method (Scheme III) uses infrared absorption at 2.95 microns for measuring the amount of DOH formed by enolization of the deuterated sugar in alkaline D20. The rate constant, kH, is calculated from the usual first-order equation ... 

Ohrui and coworkers82 exploited the highly selectively deuterated sugars available from the bromo compounds by, for example, synthesizing a- and / -(l- 6)-linked hexose disaccharides with deuterium incorporated selectively within the methylene group involved in the interunit linkage, thereby... 

As tritium is used only in tracer proportions, only the physical properties of deuterated sugars (into which the deuterium is usually introduced at 100% abundance) are of interest. Many of these properties have been discussed in Section IV, as they are very useful for localizing the deuterium. 

Tipson et a/. (1962) examined the O—D bands in the spectra of fully 0-deuterated sugars. The OH band at 3390cm" of a,/ -D-glucose was shifted, when deuterated, to 2469 cm" a wave number ratio of 1.37, and other new bands appeared. 

A final topic that has been considered (46) concerns the VCD in the CH stretohing region of the peracetates of sugars. Here, no hydroxyl hydrogen bonds can form. No VCD arises from the methyl on the acetate groups as demonstrated by deuteration. Most of the spectra have both positive and negative VCD con-... 

Radical 15, C4 (-H) , could be only tentatively identified. ENDOR spectra indicated that it was present in two slightly different conformations at 10 K. At 150 K, the ENDOR line associated with the 2.89 mT coupling decreased in intensity and that associated with the 2.80 mT line increased, indicating the radical relaxes into a more stable conformation at 150 K. A variety of small couplings were observed, but not characterized, in both conformations of 15. An unidentified likely sugar radical was detected in 2 -deoxycytidine hydrochloride through observation, in both deuterated and undeuterated crystals, of a nearly axially symmetric 0-type coupling with Aiso = 3.21 mT. It appears to exist in three different conformations at 10 K at 150 K, one of these conformations seems to disappear, and two appear to increase in concentration. 

CARBAZONES, see CARBAZIDES CARBOHYDRATES and SUGARS CARBOXYLIC ACIDS, see ACIDS, CARBOXYLIC CATALYTIC HYDROGEN-ION REDUCTION DEUTERATED COMPOUNDS, see ISOTOPES D IAZ0 COMPOUNDS DIAZONIUM SALTS ESTERS, CARBOXYLIC... 

One of the most important sugar lesion is the 3 -phosphoglycolate that is typically formed in the presence of O2 (for its excision by purified HeLa cell extracts see Winters et al. 1992). Specifically deuterated nucleoside triphosphates were used for incorporation into dsDNA by PCR (Balasubramanian et al. 1998). Hydroxyl radicals were generated by a Fenton reaction, and the yields of free 3 -phosphate end groups, 3 -phosphoglycolate and 5 -aldehyde were measured. Depending on the position of the deuteration, the yields vary with respect to a non-deuterated sample (Table 12.9). 

The functionalization at C-6 of 1,6-anhydro sugars using the previously described photobromination process allows the synthesis of chirally deuterated hydrosy methyl groups in the glucopyranose series [34] (Scheme 15). Similar sequences can be used in the galacto [35] and ribo series [36]. 

The ability to incorporate deuterium or tritium selectively into appropriate positions on nucleotides has had a tremendous impact on mechanistic studies on sugar oxidation. In particular, Stubbe and coworkers have shown that when thymidine deuterated at the 4 position is incorporated into restriction fragments, sequence-selective isotope effects are observed for cleavage by Fe-BLM (12). These isotope effects are essentially equal for the radical and carbocation pathways (Scheme... 

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