Sodium borotritide

The radioactive isotopes available for use as precursors for radioactive tracer manufacturing include barium [ C]-carbonate [1882-53-7], tritium gas, p2p] phosphoric acid or pP]-phosphoric acid [15364-02-0], p S]-sulfuric acid [13770-01 -9], and sodium [ I]-iodide [24359-64-6]. It is from these chemical forms that the corresponding radioactive tracer chemicals are synthesized. [ C]-Carbon dioxide, [ C]-benzene, and [ C]-methyl iodide require vacuum-line handling in weU-ventilated fume hoods. Tritium gas, pH]-methyl iodide, sodium borotritide, and [ I]-iodine, which are the most difficult forms of these isotopes to contain, must be handled in specialized closed systems. Sodium p S]-sulfate and sodium [ I]-iodide must be handled similarly in closed systems to avoid the Uberation of volatile p S]-sulfur oxides and [ I]-iodine. Adequate shielding must be provided when handling P P]-phosphoric acid to minimize exposure to external radiation. 

A formal synthesis of L-[6-3H]ascorbic acid was achieved when D-glucurono-6,3-lactone was reduced to L-[6-3H]gulono-l,4-lactone with sodium borotritide.354 L-Gulono-1,4-lactone has been converted into 1 by several routes (see Section III,7b,c). Starting with methyl o-xylo-2-hexulosonate, and following the method shown in Scheme 17, L-(5-2H)ascorbic acid was prepared by reduction of 121 with sodium boro-deuteride.547,548,587 In a related, but shorter, synthesis, sodium D-threo-2,5-hexodiulosonate was reduced with sodium borodeuteride to a mixture of keto-acids (see Section III,9d), which was esterified. By fractional recrystallization, methyl L-xylo-2-hexulosonate was obtained, and this was then converted598 into (5- H)l. 

Unless mass spectrometric analysis of the glycan pool is carried out, the released sugars need to be tagged to enable them to be detected during separation. Classically, the reducing end of the oligosaccharides had been reduced with alkaline sodium borotritide [132]. 

Figure 5.28 Apurinic site lyase mechanism. The probable products of sodium borotritide labelling are also shown.

TABLE 1. Incorporation of tritium from sodium borotritide into reducing ends of gentiotetraose and cell wall glucan of Pyricularia oryzae (9)... 

In the field of aldobiouronic acid derivatives an ingenious method has been devised for the preparation of radioactive disaccharides for use as substrates for o-L-iduronidase, jS-D-glucuronidase, and 2-sulpho-L-iduronate 2-sulphatase. Heparin was cleaved by the deamination procedure and the products were reduced using sodium borotritide to afford access to a-L-idopyranosyluronic and j3-D-glucopyranosyluronic acid derivatives of 2,5-anhydro-D-[l- H]mannitol. Acidic treatment in methanol of the water-soluble polysaccharides of wobaku wood, followed by acetylation, have led to the isolation of the anhydride derivative (53) which was concluded to arise by way of the corresponding aldo-... 

A synthesis of hexa-acetyl streptamine (14) from 2-acetamido-2-deoxy-D-glucose is outlined in Scheme 5. The tritium-labelled 2,6-dideoxystreptamine (15) has been prepared from a trihydroxycyclohexanone derivative by a sequence of standard reactions that included the reduction of the ketone group with sodium borotritide. ... 

Particles of hepatitis B surface antigen have been labelled after treatment with neuraminidase and D-galactose oxidase, followed by reduction with sodium borotritide. The incorporated label was detected chiefly in a glycoprotein (mol. wt. 2.8 X 10 ) that retained its serological activity after treatment with neuraminidase. 

The surface glycoproteins of rat lymphoid cells have been labelled after periodate oxidation followed by reduction with sodium borotritide. The... 

Different types of leukaemic cells have been surface-labelled by sequential treatment with neuraminidase, D-galactose oxidase, and sodium borotritide. Analysis of the surface glycoprotein profile by polyacrylamide gel electrophoresis has provided a method for the classification of leukaemic cells according to cell type and the stage of differentiation. 

One of the advantages of the pyridoxal method is the possibility of using sodium borotritide (NaBT4), which is available with a specific activity of about 116 Ci mmol Thus, radioactively labelled pyridoxyl derivatives can be obtained, allowing the detection of about 0.1 pmol of an amine or amino acid. 

A micro method for determining the structures of substituted 2-acetamido-2-deoxy-D-galactitol and -glucitol in glycoproteins, etc., has been reported. Aminodeoxy[ H]alditols resulting from periodate oxidation, reduction with sodium borotritide, and hydrolysis of nmole amounts of substituted 2-acetamido-2-deoxyalditols were separated by t.l.c. and detected by autoradiography. 

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