Glucuronate labeled, preparation

For the synthesis of D-glucuronic acid, methods of oxidation of suitable D-glucose derivatives have been devised during the past two decades these procedures have been comprehensively reviewed by Marsh,6 Mehltretter,7 and Heyns and Paulsen.8 For special purposes, for example, for the preparation of 6-I4C-labelled D-glucuronic acid, chain-extension reactions of 1,2-O-isopropylidene-a-D-xy/o-pen-todialdo-I,4-fiiranose by the cyanohydrin synthesis9 or by ethynyla-tion10 are used, but these frequently yield mixtures of D-glucuronic acid and L-iduronic acid. 

As previously mentioned, Kauss (40) has shown that the methyl donor for the formation of 4-methyl-D-glucuronic acid of hemicellulose B proved to be S-adenosyl-L-methionine, the same as in pectin. A particulate preparation from immature com cobs containing hemicellulose B was found capable of transferring the 14C-labeled methyl group from S-adeno-syl-L-methionine to a macromolecular acceptor present in the particles. The radioactive product was shown to be hemicellulose B labeled in the 4-methyl-D-glucuronic acid residues. It was isolated chiefly as 4-methyl-glucuronosyl-( 1 - 2)-D-xylose. 

Sowden82 recently has prepared D-glucuronic acid isotopically labeled at carbon atom 6 for certain chemical and biochemical studies. In this novel synthesis, 5-aldehydo-l,2-isopropylidene-D-xylofuranose88 (XVI), prepared by periodate cleavage of 1,2-isopropylidene-a-D-glucofuranose (XV), was condensed with Cu-labeled sodium cyanide. Alkaline... 

The brominated sugars are usually quite stable and can be useful for a variety of purposes [151]. Substitution of bromine with deuterium can be used for preparation of labeled carbohydrates, while substitution with hydrogen sometimes can be used for inverting the stereochemistry. Noteworthy is the conversion of D-glucuronic acid derivative 61 into the corre-... 

In the first place the discovery of the secretion of DHA-sulfate by the adrenal cortex in apparently major quantities suggested a hitherto completely unsuspected role of steroid sulfates in steroid biosynthesis and metabolism. Second, a number of steroid metabolites conjugated with two molecules of glucuronic or sulfuric acid were discovered, particularly in pregnancy urine, amniotic fluid, and in perfused placentofetal preparations. Finally, isotopic studies revealed several cases in which administered doubly labeled steroid conjugates were metabolized in the steroid part of the molecule without hydrolysis of the conjugate (e.g., D4, R5 cf. B5). 

A partially fractionated, cell-free, enzyme preparation from Type III pneumococcal cells (which had been grown in the presence of Sill depolymerase to lower the proportion of pre-existing Sill) incorporated d-glucose and D-glucuronic acid in the ratio of 1 1 from carbou-14-labeled... 

Considering the fact that an enzyme in rat kidney preparations readily converted myo-inosltol to glucuronic acid (Charalampous and Lyras, 1957), attempts were made (Burns et al., 1956) to demonstrate the formation of L-AA in plants and animals from labelled myo-inositol. However, Loewus et al. (1962) completely ruled out the possibility of myoinositol serving as an Important precursor of L-AA. 

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