摘要:

1-Deoxy-1-thioethyl-D-fructose was synthesized by two distinctly different methods. Less than the usual hindrance of the toluenesulphonyloxy group on the C-1 position in 2,3-4,5-diisopropylidene-1-O-p-toluenesulphonyl-D-fructose was found to occur in the presence of sodium ethanethiolate.

ISSN:0008-4042    

DOI:10.1139/v55-177

出版商:NRC Research Press    

年代:1955

数据来源: NRC

摘要:

Wheat gliadin has been found by two different methods to contain three N-terminal histidine residues for each molecular weight of 27,000. Trace amounts of N-terminal aspartic acid, glutamic acid, alanine, valine, and serine were also detected in the preparation used. Hydrolysis in boiling hydrochloric acid partially destroyed the di-2,4-dinitrophenyl derivative of histidine. Losses of from 5% to 25% occurred depending upon the time and conditions of hydrolysis. Carboxypeptidase did not release free amino acids from wheat gliadin but qualitative evidence for the occurrence of C-terminal glutamic acid and C-terminal "leucine" was obtained.

ISSN:0008-4042    

DOI:10.1139/v55-178

出版商:NRC Research Press    

年代:1955

数据来源: NRC

摘要:

Guanidine has been synthesized by heating under ammonia pressure an intimate mixture of finely powdered urea, ammonium chloride, and aluminum sulphate. Good yields of guanidine as the hydrochloride salt have been obtained over a wide range of conditions. The mechanism of this synthesis is briefly discussed.

ISSN:0008-4042    

DOI:10.1139/v55-179

出版商:NRC Research Press    

年代:1955

数据来源: NRC

摘要:

γ-Hydroxyglutamic acid has been synthesized by two independent methods, namely the condensation of ethyl α-acetoxy-β-chloropropionate with diethyl acetaraidomalonate, and the hydroxylation of glutamic acid. Chemical evidence is provided for the structure of the compound.

ISSN:0008-4042    

DOI:10.1139/v55-180

出版商:NRC Research Press    

年代:1955

数据来源: NRC

摘要:

High molecular weight ligninsulphonates were separated from other constituents of spent sulphite liquor by a method of dialysis allowing continuous removal of the dialyzates and their replacement by distilled water. The process was controlled by continuous analysis of the residue and dialyzate. The lower molecular weight ligninsulphonates in the dialyzates were separated from the carbohydrates by precipitating their barium salts with ethanol; four fractions corresponding to different times of dialysis were prepared in this manner. The ligninsulphonates in the dialyzed liquor were separated into four additional fractions by ultrafiltration through membranes of different pore sizes. The methoxyl, sulphur, and phenolic hydroxyl contents, neutralization equivalent weights, reducing powers, ultraviolet absorption spectra, diffusion coefficients, and number-average molecular weights of the eight fractions were determined. The molecular weights of the fractions range from 3700 to 58,000 but the integral molecular weight distribution curve indicates the presence of ligninsulphonates with molecular weights as high as 100,000.

ISSN:0008-4042    

DOI:10.1139/v55-181

出版商:NRC Research Press    

年代:1955

数据来源: NRC

摘要:

Conductivity, dyestuff adsorption, and viscosity measurements on aqueous solutions of fractionated ligninsulphonate samples having various molecular weights indicate that they behave as flexible polyelectrolytes. There is evidence that ligninsulphonates of molecular weight less than 5000 associate in solution in a manner analogous to micelle formation in colloidal electrolytes. From the variation of intrinsic viscosity with molecular weight, it may be concluded that the degree of molecular branching of the high molecular weight ligninsulphonates is greater than that of the low molecular weight fractions.

ISSN:0008-4042    

DOI:10.1139/v55-182

出版商:NRC Research Press    

年代:1955

数据来源: NRC

摘要:

The condensation of ethanol and ethylaniline was studied using alumina catalysts at 300 °C. The gel water of the alumina affects its catalytic activity. Maxima and minima in activity occur at gel water values corresponding to those previously found for the dehydration of ethanol and formic acid. There is no concurrent change in crystal structure of the alumina gel. The results suggest the initial dehydration of alcohol to ether followed by condensation of the ether and ethylaniline to give diethylaniline. It is concluded that the best and poorest spatial arrangement of ‘active points’ or adsorption spaces is established by the amount of residual gel water.

ISSN:0008-4042    

DOI:10.1139/v55-183

出版商:NRC Research Press    

年代:1955

数据来源: NRC

摘要:

The conductances, densities, and viscosities of aqueous solutions of lithium nitrate have been determined, at temperatures of 25.0° and 110.0 °C, at concentrations up to 14 molar. The results have been compared with the conductances calculated by means of the Robinson–Stokes equation and good agreement found up to about 7 molar. A short discussion of the theoretical implications is given.

ISSN:0008-4042    

DOI:10.1139/v55-184

出版商:NRC Research Press    

年代:1955

数据来源: NRC

摘要:

The synthesis of 17β-methyl-17-isodesoxycorticosterone, an epimer of the biologically active hormone homologue 17α-methyldesoxycorticosterone, is described.

ISSN:0008-4042    

DOI:10.1139/v55-185

出版商:NRC Research Press    

年代:1955

数据来源: NRC

摘要:

Extractive-free, ash-free sunflower seed heads contained lignin (12.3%), pectin (27.5%), alkali-soluble polysaccharides (8.2%), and α-cellulose (52.0%). Pectin and polysaccharides were separated by successive extraction of the seed heads with ammonium oxalate – oxalic acid solution and 5% aqueous sodium hydroxide. The pectin was 37% esterified with methyl groups and yielded only galacturonic acid when hydrolyzed. The polysaccharides yielded, on hydrolysis, a mixture of neutral sugars and an aldobiouronic acid. The neutral sugars consisted ofD-xylose (59.3%),D-glucose (23.5%),D-galactose (16.2%), and traces of arabinose and rharnnose. Fractionation of the polysaccharide acetate indicated that the three main sugars were constituents of three different polysaccharides. The aldobiouronic acid (1.53% of the polysaccharides) was shown to be 3-O-α-(D-glucopyruronosyl)-D-xylopyranose.

ISSN:0008-4042    

DOI:10.1139/v55-186

出版商:NRC Research Press    

年代:1955

数据来源: NRC