Sodium borohydride treatment

FIGURE 10.10 The reaction of tridated sodium borohydride with the aspartyl phosphate at the active site of Na, K -ATPase. Acid hydrolysis of the enzyme following phosphorylation and sodium borohydride treatment yields a tripeptide containing serine, homoserine (derived from the aspartyl-phosphate), and lysine as shown. The site of phosphorylation is Asp" in the large cytoplasmic domain of the ATPase. 

Reduction with sodium borohydride Treatment of monosaccharide with sodium borohydride (NaBH4) reduces it to a polyalcohol called an... 

Sodium Borohydride Treatment. The pulp (1% consistency) together with EDTA (0.15% consistency) was suspended in water and stirred for one hour at room temperature, after which it was washed and filtered. The pulp was then suspended in water (1% consistency) and sodium borohydride was added (50% on pulp basis). The pulp suspension was stirred at room temperature for two days, followed by filtration, washing with water and air-drying at room temperature. 

Reaction Pathway and Products. In the presence of a catalytic amount of a tetraphenylporphyrin (TPP) Mn(III) complex (34) and sodium borohydride, treatment of cyclohexene with excess oxygen (air) in benzene-ethanol leads effectively to cyclohexanol and cy-clohexenol. The reaction is quite different from the known autoxidation catalyzed by TPP Mn(III) in the absence of NaBH4 (Figure 7). The most significant characteristics of the present TPPMn-NaBH4-02 reaction compared with the autoxidation are ... 

The high 77-deficiency at C-7 is also apparent from the nucleophilic addition reaction with sodium borohydride selective formation of the 6,7-dihydro derivative (566) results with this reagent. The reaction may also proceed further by reductive loss of the 7-substitutent (76CPB235). In the pyrazine analogue (567) both LAH and sodium borohydride treatment lead to saturation of the pyrazine ring (78JOC341). 

Stabilization of Paper Through Sodium Borohydride Treatment... 

The treatment of bleached kraft pulp with sodium borohydride followed by incorporation of basic calcium salts increased the stability of paper made from this pulp by 1.5-2.6 times. When manufactured paper, rather than pulp, was subjected to sodium borohydride treatment followed by washing with an aqueous solution of calcium hydroxide, the stability of the paper increased by as much as 4 times for groundwood paper and 30 times for bleached kraft paper. 

The effect of a reducing sodium borohydride treatment followed by a mildly alkaline wash on the physical properties and stability of paper was studied. Test papers were characterized by measuring their initial pH value, brightness, and folding endurance. Then they were subjected to borohydride treatment and washed with dilute calcium hydroxide solution or deionized water. The concentrations of sodium borohydride... 

Sodium borohydride treatment of this indolenine gives exclusively the indole-indoline (24), identical in all characteristics except rotation with (24) obtairied from hodgkinsine. It is possible that the amorphous quadrigemine A is a mixture of stereoisomers. 

Sodium borohydride treatment of reduction product 2 gives reduction product 3 (80), a di-indoline, which shows no carbonyl absorption in its i.r. spectrum. The product gives only a mono-N-acetyl derivative (81). The secondary hydroxy-group must be sterically hindered after acylation of the neighbouring nitrogen has taken place. J... 

IRua -OsXjM-O CMeljl was carried out according to the procedures described in [4], [5], and [6], respectively. Ruthenium black and Ru/Si02 were prepared by sodium borohydride treatment of RUCI3 in methanol and RUCI3 on Si02,... 

Sodium borohydride treatment of alpha acids or of iso-alpha acids leads to the so called rho-iso-alpha acids. This reduced form of the iso-alpha acids accounts for stabilization against sunstruck flavour, while still giving acceptable bitterness (see earlier chapters). 

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