Acid Reversion

Shammas M.A., Simmons C.G., Corey D.R., Reis R.J.S. Telomerase inhibition by peptide nucleic acids reverses immortality of transformed human cells. Oncogene 1999 18 6191-6200... 

Warenycia MW, Steele JA, Karpinski E, et al. 1989d. Hydrogen sulfide in combination with taurine or cysteic acid reversibly abolishes sodium currents in neuroblastoma cells. Neurotoxicology 10 191-199. 

Aldrich humic acid, reversed phase separation, Landrum et al. 1984)... 

Amino acids with modified side-chains are frequently encountered in biological systems. Among all the modifications involving the side-chain of the amino acids, reversible glyco-sylation and phosphorylation play a central role in regulating the biological functionalities of numerous proteins. 

The nucleophilic site (-Q-) of ROH then bonds to the C" of the carbocation, forming an onium ion of the ether, which loses a proton to the solvent alcohol (ROH) and becomes the ether product. Aqueous acid reverses the reaction of (a), reforming the same intermediate carbocation. This loses a proton to give the C==C, rather than reacting with water to give the very unstable alcohol-analog of the ether. 

Dyall, S., Michael, G., and Michael-Titus, A. (2010). Omega-3 fatty acids reverse age-related decreases in nuclear receptors and increase neurogenesis in old rats. J. Neurosci. Res. 88, 2091-2102. 

Fatty acid chains are taken apart two carbon atoms at a time by (3 oxidation. Biosynthesis of fatty acids reverses this process by using the two-carbon acetyl unit of acetyl-CoA as a starting material. The coupling of ATP cleavage to this process by a carboxylation-decarboxylation sequence, the role of acyl carrier protein (Section H,4), and the use of NADPH as a reductant (Section I) have been discussed and are summarized in Fig. 17-12, which gives the complete sequence of... 

Analytical Properties (i-Cyclodextrin (cycloheptamylose) normal phase separation of positional isomers of substituted benzoic acids reverse phase separation of dansyl and napthyl amino acids, several aromatic drugs, steroids, alkaloids, metallocenes, binapthyl crown ethers, aromatics acids, aromatic amines, and aromatic sulfoxides this substrate has seven glucose units and has a relative molecular mass of 1135 the inside cavity has a diameter of 0.78 nm, and the substrate has a water solubility of 1.85 g/ml, although this can be increased by derivatization Reference 13-28... 

Mild, acid hydrolysis of European-larch arabinogalactan results in the formation of 3-0-/3-L-arabinopyranosyl-L-arabinose (XXXIX). 26 Although this disaccharide has been isolated as an acid-reversion product from L-arab-inose,131 it is accompanied under these conditions by two other arabinose-containing disaccharides, neither of which was detected in the larch polysaccharide hydrolyzate. Since hydrolysis of methylated -galactan gave approximately equimolar proportions of 2,3,4-tri-O-methyl-L-arabinose and 2,5-di-O-methyl-n-arabinose, traces of 2,3,5-tri-O-methyl-L-arabinose, and no mono-O-methyl-L-arabinose, it is clear that the L-arabinose units must arise from an arabinogalactan rather than from an arabinan, and that the majority of these must be present in 3-0-/3-L-arabinopyranosyl-L-arabino-furanose side-chains (XLV) linked, in some way as yet unknown, to the framework of D-galactose units (XLI). 

Ethylene diamine tetraacetic acid and nitroacetic acid Reverse phase column Agtrichloro acetic acid (pH<2) Amino acids, citric acid and fiilvic acid do not interfere Carbon paste electrode [28]... 

There are scattered reports that phenolic acids inhibit a variety of enzymes, and it is evident that these compounds can block the function of many enzymes if they are sufficiently concentrated at the site of enzymatic functions. Activities of amylase, maltase, invertase, acid phosphatase and protease were suppressed by ferulic acid in tests using maize seeds and seedlings.17,50 Exogenously applied gibberellic acid reversed the effect of ferulic acid on amylase and acid phosphate. 

Source From A. Thompson et al., Acid Reversion Products from D-Qlucose, J. Am. Chem. Soc., Vol. 76, pp. 1309-1311,1954. 

Positive correlations between plasma levels of vanadium and manic depressive psychosis have been observed in a number of laboratories160"163. Symptoms are augmented when patients are administered vanadium for 10 days162, but large doses of ascorbic acid reverses this effect possibly through the reduction of vanadium(V) to van-adium(IV)160. It has been suggested that manic depressives may have a defect in the sodium pump or that vanadium is a factor in controlling the Na+, K+-ATPase activity in this illness. 

The cation corresponding to the two-electron oxidation may be generated, as mentioned in Section IV,B, 2 from the 5-oxides with acids the formation of 5-oxides from the cations is thus an acid-reversible reaction. 

As mentioned in Section IV,C, Tozer and Dallas Tuck investigated the correlation between rate constants of S+ decay and the nature and position of the substituents. Using a technique which eliminated the influence of all acid-reversible reactions, the rate of hydroxylation at position 3 was determined. The controlling electronic factor is the influence of the nitrogen atom at position 10, there being linear correlation between reaction rates and Oj, constants of the substituents at position 3 and constants of those located at position 2. 

This treatment was applied to the polymerization of 3,3-bis-(chloromethyl)-oxetane (irreversible propagation) and, more recently, to the polymerization of cyclic esters of phosphoric acid (reversible propagation) ... 

The type of mutarotation kinetics found experimentally is strongly dependent on the solvent. Forward mutarotation in acetic acid yields a plot of log d[a /dt versus log ([a]( — [ ] ) which is linear over 97% of the reaction with a slope of 1.33. On the other hand the rate is virtually invariant over two-thirds of the reaction in a solvent of 30% water-70 % acetic acid. Reverse mutarotation in acetic acid-n-propanol appears to follow first-order kinetics over 90% of the transformation. From these experiments and the fact that the enthalpies of form I and form II are essentially identical (Steinberg et al., 1960a) it seems likely that solvation is decisive not only in determining the kinetic pathway of mutarotation but also the structural pattern which is stabilized in a given solution. 

Variety of racemic carboxylic acids reversed-phase silica gels coated with copper(ll) complexes of... 

The TiOiCllO) surface facilitates both molecular and dissociative adsorption of formic acid. The dissociative adsorption of formic acid (to form surface formates) is mediated by surface oxygen anions low-energy electron diffraction studies have shown that formate is ordered into (2x1) domains with formates bridging the surface titanium cations. This ordered layer is disrupted on heating formate may recombine with surface hydroxyl groups to desorb formic acid (reverse of reaction 2) or it may decompose to form the dehydration products CO and H2O, as well as small amounts of CO2 and H2 [43]. 

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