摘要:

The base obtained by hydrolysis of the chief alkaloid present inDelphinium BrowniiRydb. is shown to be identical with lycoctonine by comparison with an authentic sample of the latter. The perchlorate, picrate, and methiodide of lycoctonine from both sources have been compared and found to be identical.

ISSN:1923-4287    

DOI:10.1139/cjr46b-001

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

Thirty samples of Jersey milk were analysed for each of titratable acidity, free carbon dioxide, carbonates, citric acid and citrates, casein, lactalbumin and lactoglobulin, and inorganic phosphates. Partial correlation coefficients were calculated for titratable acidity with each of the other variables. The only significant one was that between titratable acidity and inorganic phosphates. Therefore it is concluded that inorganic phosphates are the primary cause of the acidity of fresh milk.

ISSN:1923-4287    

DOI:10.1139/cjr46b-002

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

The viscosity of aqueous extracts of Irish moss (Chondrus crispus) has been found to depend mainly on the concentration of the neutral salts present in the solution. Samples of dialyzed polysaccharide, however, show considerable variation. The relation between thespecific viscosityand theconcentrationin dilute aqueous solutions and formamide is such that ηsp=acv+bcc2, where ηspis thespecific viscosity,cvtheconcentration, and bothaandbare constants. In aqueous solution these constants are decreased by the addition of neutral salts. A rise in temperature causes a decrease in viscosity. This decrease is less rapid for solutions in formamide and aqueous solutions containing neutral salts. The effectiveness of individual salt solutions in promoting a decrease in viscosity coincides with their effect in producing precipitation of the polysaccharide. The order of decreasing effectiveness was: potassium chloride, calcium chloride, sodium chloride. When the concentration of gelose is such that gelation takes place on standing, measurements of viscosity become irregular and are not reproducible. The concentration of gelose at which the regular viscosity measurements are obtained decreases with increasing concentration of neutral salts. The rigidity of the gels so formed also decreases. The firmness of a gel seemingly depends on the concentration and type of neutral salt, as well as on theintrinsic viscosityof the polysaccharide. The intrinsic viscosity is defined as: the limit of the specific viscosity as the concentration approaches zero.

ISSN:1923-4287    

DOI:10.1139/cjr46b-003

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

A method of measuring the stabilizing power of extracts of Irish moss has been developed. This is based on the quantity of calcium oxalate, expressed as grams per gram of dry extract, held in suspension under specific conditions. The logarithm of this quantity plotted against the concentration of gelose gave a straight line relation. Results were accurate within 1%. Condition of measurement required a temperature below 60 °C., pH between 5.5 and 8.5, and a low concentration of neutral salts. Results were compared with those obtained with chocolate powder stabilized in milk. An equationM=K/tpcnhas been developed and verified, in which the constantKis shown to be numerically an index of stabilizing power, and whereMis the number of grams of calcium oxalate held in suspension per gram of extract at a concentration ofcgrams of extract per 100 ml. after centrifuging for timet.K,p, andnare constants:pandnrepresent the tangents of lines plotted for the logarithms ofMagainsttandc, respectively.

ISSN:1923-4287    

DOI:10.1139/cjr46b-004

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

A new sulphur-containing α-amino acid, S-methyl-β,β-dimethylcysteine has been prepared from S-benzyl-β,β-dimethylcysteine. These two compounds and the intermediate β,β-dimethylcysteine may be of physiological importance.S-Benzyl-β,β-dimethylcysteine has been prepared by the addition of benzyl mercaptan to α-benzoylamino-β,β-dimethylacrylic acid, its azlactone, and methyl ester, followed by hydrolysis.In addition to the above three new sulphur-containing α-amino acids, the following compounds are described, as far as the authors are aware, for the first time: methyl α-benzoylamino-β,β-dimethylacrylate, S-benzyl-N-benzoyl-β,β-dimethylcysteine and its methyl ester, the hydantoin of S-benzyl-β,β-dimethylcysteine, and S-benzyl-β,β-dimethylcysteine ethyl ester hydrochloride, and helianthate.

ISSN:1923-4287    

DOI:10.1139/cjr46b-005

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

The 2,6-dichlorophenolindophenol method of assay of vitamin C has been critically examined with respect to a number of fresh, boiled, and otherwise treated plant materials. Comparative values are given for ascorbic acid as determined by the usual method, for non-vitamin C reductants, and for dehydroascorbic acid.In the fresh uncooked materials examined, non-vitamin C reductants were not found and only in cabbage, peas, and pigweed leaves did dehydroascorbic exceed 10% of the ascorbic acid value.Boiling produced significant amounts of non-vitamin C reductant in cabbage and peas.In rose hips the dye titration gives an accurate measure of ascorbic acid. The amounts of dehydroascorbic acid and non-vitamin C reductant, even under storage at room temperature for over a year, are insignificant.It is concluded that the 2,6-dichlorophenolindophenol method of assay of vitamin C is highly specific but in the case of certain cooked foodstuffs non-vitamin C dye reductants may, without check by other methods, introduce significant errors.

ISSN:1923-4287    

DOI:10.1139/cjr46b-006

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

A method has been described for the isolation of ascorbic acid from rose hips.

ISSN:1923-4287    

DOI:10.1139/cjr46b-007

出版商:NRC Research Press    

年代:1946

数据来源: NRC