摘要:

A structural isomer of sparteine, Ψ-sparteine, has been synthesized from 2,2′-dipyridylmethane which was condensed via its lithium salt with β-bromomethylmalonic ester, followed by fission of the ether link. The product of the condensation, αα-di(2-pyridyl)-γγ-dicarbethoxy-propane, was reduced catalytically to the corresponding dipiperidyl compound which on heatingin vacuoreadily lost ethanol, giving rise to two isomeric dilactams. Each dilactam was reducible to a different isomer of sparteine. Just like sparteine, Ψ-sparteine can exist in three stereoisomeric forms, two of which, however, are internally compensated and therefore not resolvable.

ISSN:0008-4042    

DOI:10.1139/v52-068

出版商:NRC Research Press    

年代:1952

数据来源: NRC

摘要:

The 2,4-dinitrophenyl derivatives of a number of amino compounds have been prepared and their X-ray powder diffraction measurements made. This appears to be the first time this information has been obtained and it is submitted as a method of identification.

ISSN:0008-4042    

DOI:10.1139/v52-069

出版商:NRC Research Press    

年代:1952

数据来源: NRC

摘要:

A simple, quantitative method for determination of amino acids in about 300 µgm. protein is described. The amino acids are separated by two-dimensional paper chromatography. The chromatograms are sprayed with 2% ninhydrin and the color is developed under controlled and standardized conditions. The colored areas are cut out, eluted, and the color intensity is read in a photometer. The following factors have been shown to affect the color reaction of ninhydrin with amino acids on paper chromatograms: the quality of the ninhydrin; its concentration; time of color development; and the environmental temperature and humidity. Complete oxidation of the hydrolyzate is necessary for accurate quantitative determinations of cysteine, cystine, glutamic acid, aspartic acid, methionine, and valine. Strict standardization of the length of the solvent run is also important for reproducibility in the analyses of some amino acids.Bovine serum albumin has been analyzed by this method and the results found to be in excellent agreement with previously published values.

ISSN:0008-4042    

DOI:10.1139/v52-070

出版商:NRC Research Press    

年代:1952

数据来源: NRC

摘要:

Monosubstituted cyanoacetic esters, obtained by condensation of 1-bromo-3(s)-phenoxypropanes (s = o-Cl,o-Br,o-I,o-, m-,andp-NO2) or 1-bromo-2(s)-phenoxyethanes (s = o-Cl,o-Br,o-I, andm-NO2) with ethyl cyanoacetate by means of potassium carbonate, were transformed through a Curtius degradation into cyanoacetisocyanates. These compounds by hydrolysis in acid or alkaline medium gave α-amino acids. However, hydrolysis of the corresponding carbobenzyloxy- or carbethoxyaminonitriles afforded better yields. The carbobenzyloxyaminonitriles were more readily hydrolyzed in aqueous hydrochloric acid than the carbethoxyaminonitriles. Moreover, the mild action of dry hydrochloric acid on the carbobenzyloxy derivatives yielded the α-amino acids readily whereas similar treatment of the carbethoxy derivatives gave the carbethoxyamino acids.

ISSN:0008-4042    

DOI:10.1139/v52-071

出版商:NRC Research Press    

年代:1952

数据来源: NRC

摘要:

Physical properties and X-ray crystallographic data of three major alkaloids of theLycopodiumgroup and of some of their hydrohalide salts were determined. The hydrobromide and hydroiodide of annotinine were shown to be isomorphous and therefore suitable for a detailed investigation by X-ray diffraction methods.

ISSN:0008-4042    

DOI:10.1139/v52-072

出版商:NRC Research Press    

年代:1952

数据来源: NRC

摘要:

The usefulness of electrophoretic patterns of polysaccharides in molar alkali as a general criterion of the purity of these substances has been studied. No clear separation of the components of a hemicellulose, of wheat starch, or of potato starch could be demonstrated. Similarly, mixtures of wheat starch and inulin, pectin and sodium alginate, laminarin and sodium alginate, inulin and wheat starch plus sodium alginate could not be resolved in 1 Mpotassium hydroxide. Nonetheless, mixtures of laminarin and sodium alginate separated rapidly at pH 6.8 and 10.4. Contrary to previous reports, it is shown that the electrophoretic technique cannot be used with confidence as a general criterion of the purity of polysaccharides in molar alkali. However, it may be applicable for the characterization and fractionation of a limited class of polysaccharides which are soluble close to neutrality.

ISSN:0008-4042    

DOI:10.1139/v52-073

出版商:NRC Research Press    

年代:1952

数据来源: NRC

摘要:

By means of hydrogenation, oxidation, and isomerization experiments it has been established that the chemistry of veatchine and garryine parallels the chemistry of atisine and isoatisine.Dehydrogenation of theGarryaalkaloids yields a base C16H15N, which, on the basis of comparison of ultraviolet spectra, might be a substituted phenanthridine. 1-Methyl-7-ethyl phenanthrene has also been obtained. The chemistry and structure of the aconite andGarryaalkaloids is discussed in the light of the present work.

ISSN:0008-4042    

DOI:10.1139/v52-074

出版商:NRC Research Press    

年代:1952

数据来源: NRC