scholarly journals Chromatographic Fractionation of the Acetic Acid Soluble Proteins of Wheat Flour on Carboxymethyl-Cellulose

1961 ◽  
Vol 14 (4) ◽  
pp. 690 ◽  
Author(s):  
DH Simmond ◽  
DJ Winzor

The acetic acid soluble proteins extracted from wheat flour have been separated into 11 fractions by a chromatographic procedure using columns of carboxymethyl- cellulose, equilibrated with O� 005M acetate buffer, pH 4�1. Under theso conditions one fraction passes unretarded through the column. Eight further fractions are eluted at pH 4� 1 by employing a gradient to O� 2M N aCl in the presence of 1M dimethyl formamide (DMF) which prevents protein precipitation at ionic strengths greater than 0�03.

1960 ◽  
Vol 235 (4) ◽  
pp. 989-994
Author(s):  
Alexander Kessler ◽  
Hyman Rosen ◽  
Stanley M. Levenson

1970 ◽  
Vol 49 (3) ◽  
pp. 621-625 ◽  
Author(s):  
Stephen H.Y. Wei

The electron microprobe was used to analyze the calcium and phosphorus concentrations of sound, acid-etched, and remineralized enamel. By use of a weak acetic acid-potassium acetate buffer, it was found that the demineralization probably affected only the first 10 micrometers of the enamel surface. This demineralized enamel was successfully remineralized by the use of a calcifying solution. The changes in calcium and phosphorus concentrations and the Ca/P ratios were determined.


1963 ◽  
Vol 16 (2) ◽  
pp. 342 ◽  
Author(s):  
Janet SD Graham

An improved apparatus and procedures for starch-gel electrophoresis of proteins of wheat flour are described; highly reproducible separation of the protein components was achieved. By starch-gel electrophoresis it was shown that similar protein components occur in the extracts of wheat flour obtained with a variety of solvents; however, there were marked differences in the proportions of these components in various extracts. Several protein components were present in the fJ'actions separated by ion-exchange chromatography of' the proteins soluble in Bodium pyrophosphate and of those soluble in acetic acid; some fractions containeda number of similar protein components.


2019 ◽  
Vol 8 (2) ◽  
pp. 553-557 ◽  

Model molecules for sodium carboxymethyl cellulose (Na-CMC) (monomer), glycerol, acetic acid and Na-CMC-glycerol-acetic acid are optimized with Density Functional Theory (DFT) at B3LYP/3-21G*. For the optimized models, total dipole moment (TDM), the highest occupied and lowest unoccupied molecular orbitals (HOMO/LUMO band gap energy), and molecular electrostatic potentials (ESP) are calculated at the same method to give an explanation for the possibility of using Na-CMC-Glycerol-acetic acid model molecule in electrochemical devices, gas sensors and batteries. As a result of the substitution of Na-CMC with glycerol, TDM increased from 7.7141 Debye to 22.4942 Debye which is approximately equal to three times that of Na-CMC. However, HOMO/LUMO band gap energy decreased from 0.9040 eV to 0.5072 eV. After the addition of acetic acid to Na-CMC-glycerol model, TDM increased to24.7270 Debye and HOMO/LUMO band gap energy decreased to 0.4939 eV. Both TDM and HOMO/LUMO band gap energy values are improved by increasing the acetic acid units, where TDM became 25.3510 Debye and HOMO/LUMO band gap energy decreased to 0.3815 eV. The results of ESP indicated that the addition of glycerol and acetic acid to Na-CMC increased the electronegativity of Na-CMC which in turn enhanced its electronic properties.


1967 ◽  
Vol 16 (2) ◽  
pp. 107-117 ◽  
Author(s):  
David J. Silver ◽  
Donald G. Comb

1968 ◽  
Vol 107 (3) ◽  
pp. 335-340 ◽  
Author(s):  
D. K. J. Tommel ◽  
J. F. G. Vliegenthart ◽  
T. J. Penders ◽  
J F Arens

1. Peptides and α-amino acids, occurring in mixtures from various sources, can be separated into one fraction containing the amino acids and several peptide fractions. This is achieved by chelation of the mixture with Cu2+ ions and subsequent chromatography of these chelates over the acetate form of diethylaminoethylcellulose or triethylaminoethylcellulose. 2. The amino acid fraction is obtained by elution with 0·01m-collidine–acetate buffer, pH8·0. 3. Peptide fractions are eluted with 0·01m-collidine–acetate buffer, pH4·5, 0·17n-acetic acid and 0·1n-hydrochloric acid respectively. 4. With the exception of aspartic acid and glutamic acid, which are partly found in the acidic peptide fraction, the amino acids are completely separated from the peptides. 5. Contamination of the acidic peptide fraction with glutamic acid and aspartic acid can be largely avoided by previous addition of an excess of arginine. 6. Copper is removed from the eluates by extraction with 8-hydroxyquinoline in chloroform.


1972 ◽  
Vol 50 (19) ◽  
pp. 3239-3241 ◽  
Author(s):  
R. A. Cox ◽  
J. W. Thorpe ◽  
J. Warkentin

The ratio of rate constants for exchange at the methylene and methyl positions of butanone, [Formula: see text], is shown to be near 1.69 in 1:1 acetic acid–acetate buffer; nearly twice the value (0.86) for deuterioxide catalysis at 54.8°. Methods of obtaining rate constants for acetate catalysis from composite rates (acetate and deuterioxide), or from rates in buffered media, are shown to be adequate for estimating rate ratios.Detailed temperature dependence of the relative rate constants for either system is not yet available but the effects are known to be small. For butanone enolizations the isokinetic temperature is in the neighborhood of 35°, when reaction is catalyzed by deuterioxide in aqueous media.


1980 ◽  
Vol 26 (7) ◽  
pp. 910-912
Author(s):  
P S Draganac ◽  
S J Steindel ◽  
W G Trawick

Abstract A "high-performance" liquid-chromatographic procedure for 5-hydroxy-3-indoleacetic acid is described and compared with a colorimetric method in which 1-nitroso-2-naphthol is used. The analyte and an internal standard, p-nitrobenzoic acid, were extracted into diethyl ether from urine at pH 4.0 (acidified with HCl) to which sodium chloride had been added, and the ether was back-extracted with acetate buffer, pH 9.2. Aliquots of this extract were injected into a reversed-phase liquid-chromatographic column and eluted with pH 3.5 acetate buffer/methanol (95/5 by vol); the effluent was monitored at 254 nm. The precision (CV) of the method was 11.8% at 1.8 mg/L, 5.5% at 92 mg/L. Analytical recovery averaged 84%. The colorimetric method gave higher values for the analyte than did the chromatographic method for all patients' urines.


2021 ◽  
Vol 1224 ◽  
pp. 129013 ◽  
Author(s):  
Rania Badry ◽  
Hend A. Ezzat ◽  
Sherif El-Khodary ◽  
Mohamed Morsy ◽  
Hanan Elhaes ◽  
...  

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