Potassium reducing ability

Yoon and Kim have prepared potassium triphenylborohydride (KPhjBH) and examined the reducing ability toward alkyl halides. n-Octyl iodide is reduced within 1 h at 0 °C, whereas n-octyl bromide takes 24 h for complete reduction. Secondary bromides are inert under these conditions. 

Acute renal failure, e.g. cuninoglycosides, cisplatin Nephrotic syndrome, e.g. penicillamine, gold, cap-topril (only at higher doses than now recommended) Chronic renal failure, e.g. NSAIDs Functional impairment, i.e. reduced ability to dilute and concentrate urine (lithium), potassium loss in urine (loop diuretics), acid-base imbalance (acetazolamide). 

These drugs affect potassium conductance, not only in islet cells, but also in coronary arteries and the myocardium. Therefore, they can exacerbate ischemic damage in the compromised heart, as a result of a reduced ability to relax cardiac and vascular smooth muscle. 

Several simple tests illustrate the oxidizing and reducing ability of NaB03. Place two strips of moistened starch-potassium iodide test paper opposite each other in the concave dip of a watch glass. Place some crystals of your sodium perborate tetrahydrate, NaB03 4H20, on one of the strips, and then add a drop of 6 M acetic acid, HC2H3O2, solution over the crystals. Describe what you observe in TABLE 35.1C. Place a drop of 30%... 

ICR, mprmling control r ion SPF, specific patho n-free KB1O3, potassium bromate SOD, superoxide dismutase FRAP, ferric-reducing ability of plasma MDA, malondialdehyde NO, nitric oxide TBARS, thiobarbituric acid reactive substances GSH, glutathione GP, glutatiiione p oxidase CAT, catalase activity. 

Mordant dyes generally have the characteristics of acid dyes but with the ability in addition to form a stable complex with chromium. Most commonly, this takes the form of two hydroxy groups on either side of (ortho to) the azo group of a monoazo dye, as illustrated for the case of C. I. Mordant Black 1 (151). The dye is generally applied to the fibre as an acid dye and then treated with a source of chromium, commonly sodium or potassium dichromate. As a result of the process, the chromium(vi) is reduced by functional groups on the wool fibre, for example the cysteine thiol groups, and a chromium(m) complex of the dye is formed within the... 

Lithium reduces the kidney s ability to concentrate urine and may cause a nephrogenic diabetes insipidus with low urine specific gravity and low osmolality polyuria (urine volume greater than 3 L/day). This may be treated with loop diuretics, thiazide diuretics, or triamterene. If a thiazide diuretic is used, lithium doses should be decreased by 50% and lithium and potassium levels monitored. 

The most intriguing difference between the chemical properties of cyclopolysilanes and those of cycloalkanes is the ability of the former to form either anion or cation radicals upon one-electron reduction or oxidation, respectively. For example, the cyclic pentamer (Mc2Si)5 is reduced to the corresponding radical anion by sodium-potassium alloy in diethyl ether [see eqn (4.1) in Section 4.1.3], whereas the hexamer (Me2Si)6 is oxidised by aluminium trichloride in dichlor-omethane to the corresponding cation radical. In both cases the EPR spectra of the radical ions can be interpreted in terms of a-electron delocalisation over the entire polysilane ring (see Section 10.1.4.1). In this respect, the cyclosilanes resemble aromatic hydrocarbons rather than their aliphatic analogues. 

Substances inhibiting the development of the secondary flame are those which inhibit burning reactions. The strongest of the substances known to possess this property is the potassium ion. Its ability to prevent the development of a secondary flame was demonstrated by Dautriche [39] as early as 1908. Since then potassium nitrate has been employed in the manufacture of flash-reducing charges added to the charges of ordinary propellant. 

The results for effects upon mechanical stability are summarised in Table II. That lithium laurate behaves similarly to, say, potassium laurate is perhaps surprising, in that it is known that a lithium salt is mor ffective in reducing the mechanical stability of natural rubber -ftian is the corresponding potassium salt (6.). The inference has been drawn that the counterion of the car-boxylate soap has a negligible effect upon the ability of the soap to enhance mechanical stability, relative to the effect of the anion, at least for those cations for which specific adsorption effects are absent. 

Scientists at Merck have reported a number of biocatalytic routes derived from screening various microorganisms targeted to produce key intermediates that are then combined with chemical reactions to prepare the target molecule. The biocatalytic step was often carried out by necessity as a result of poor chemical yield, low optical purity, or both. 6-Bromo-P-tetralone (2) was reduced to (S)-6-bromo-P-tetralol (3) by the yeast Trichosporon capitatum MY 1890 (Scheme 19.6).79 The tetralol 3 is a key intermediate for the synthesis of MK-0499 (4), a potassium channel blocker. The (S)-P-tetralol 3 was produced in gram quantities with an ee of >99% to support further development of MK-0499. Baker s yeast was tested for its ability to carry out this reduction but showed insignificant product formation. 

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