摘要:

Sedimentation and viscosity measurements were made on bovine serum albumin during denaturation at pH 9.9 in 8.0 Murea in the presence of sodium-p-chloromercuribenzoate. The results suggested that the urea caused a rapid initial increase in the axial ratio and equivalent volume of the protein molecule. A subsequent slower increase in asymmetry was attributed to the effect of the mercury compound.

ISSN:0008-4042    

DOI:10.1139/v55-120

出版商:NRC Research Press    

年代:1955

数据来源: NRC

摘要:

The Raman spectrum of furfural has been obtained photoelectrically in the liquid over a temperature range of 50° and in solution. The infrared spectrum has been obtained for the solid, the liquid (over a temperature range of 90°), and in dilute solution over a 50° temperature range. The vibrational spectrum is interpreted in terms of an equilibrium mixture of two rotational isomers with planar configuration. The isomer with higher electric moment is the more stable form in the liquid and in the solid.

ISSN:0008-4042    

DOI:10.1139/v55-121

出版商:NRC Research Press    

年代:1955

数据来源: NRC

摘要:

Methyl ethyl ketone has been photolyzed at temperatures between 25° and 240 °C., at varying pressures and intensities. Azomethane has also been photolyzed in the presence of methyl ethyl ketone. It is concluded that the ratio of disproportionation to recombination for a methyl and an ethyl radical is of the order of 0.04. The activation energy for the abstraction of hydrogen from the ketone by methyl is 7.4 ± 0.1 kcal., and by ethyl it is 8.0 ± 0.1 kcal.

ISSN:0008-4042    

DOI:10.1139/v55-122

出版商:NRC Research Press    

年代:1955

数据来源: NRC

摘要:

DL-1,2-O-Cyclohexylideneglycerol was prepared by reacting cyclohexanone and glycerol in the presence of sulphuric acid. It is miscible with all common organic solvents and is slightly soluble in water. It is not affected by hydrogenolysis at 25 °C. over palladous oxide at 50 p.s.i. for 24 hr. TheDL-1,2-O-cyclohexylidene-3-O-p-nitrobenzoylglycerol is readily cleaved by mineral acids to yield 3-O-p-nitrobenzoylglycerol. Proof of the 1,2 ketal structure was obtained by (a) preparation of the monomethyl derivative, acid hydrolysis, and periodic acid oxidation of the resultant 1-monomethyl ether of glycerol and (b) treatment of the tosyl derivative with sodium iodide which gave a 93% yield of sodiump-toluenesulphonate.

ISSN:0008-4042    

DOI:10.1139/v55-123

出版商:NRC Research Press    

年代:1955

数据来源: NRC

摘要:

A series of oligosaccharides were prepared by autoclaving wheat straw hemicellulose at 120 °C. in distilled water. The di- to the hepta-saccharide inclusive were shown to be members of the (1 → 4)-β-D-xylopyranose series. The octasaccharide was shown to be doubly branched. Certain aspects of the structure of wheat straw hemicellulose are discussed on the basis of these results.

ISSN:0008-4042    

DOI:10.1139/v55-124

出版商:NRC Research Press    

年代:1955

数据来源: NRC

摘要:

The effect of particle size on the heat capacity of solids has been investigated using lattices with free boundaries as models. A monatomic lattice shows a low temperature effect associated with the acoustic modes. This can be compared with results obtained from a continuum model. With a diatomic lattice, however, an effect is also associated with the optical modes and is apparent at higher temperatures. The possibility that this latter effect can explain some recent experimental results is examined.

ISSN:0008-4042    

DOI:10.1139/v55-125

出版商:NRC Research Press    

年代:1955

数据来源: NRC

摘要:

A further study has been made of the degradation of carrageenin in aqueous solution. An 80 °C. extract ofChondruscrispusdegraded more rapidly than a preparation from which a 30 °C. extract had been first removed. The latter preparation could be degraded to a lower limiting intrinsic viscosity under suitable conditions. Degradation was mainly random, but a more rapid initial degradation was observed under all conditions studied. The presence of dissolved oxygen accelerated the reaction above 60 °C. Maximum stability was observed in an inert atmosphere at pH 9 in the presence of salts. Hydroxymethylfurfural and formic acid were identified as products, the yield of the former being higher than fromD-galactose alone. The results have been discussed in the light of recent work on the constitution of the polysaccharide.

ISSN:0008-4042    

DOI:10.1139/v55-126

出版商:NRC Research Press    

年代:1955

数据来源: NRC

摘要:

The polysaccharide, laminarin, was prepared from the marine alga,Laminariadigitata, and was sulphated with chlorosulphonic acid in pyridine and in liquid sulphur dioxide at temperatures below 0°. Derivatives containing both O-sulphate and N-sulphate groups were prepared by sulphating β-aminoethyl ethers of laminarin obtained by the reaction of laminarin with ethylenimine. These derivatives were found to act as anticoagulants for bloodinvitro. The preparations with highest sulphate were most active, and for equivalent sulphate that with both O-sulphate and N-sulphate groups was more active than the one containing only the former.

ISSN:0008-4042    

DOI:10.1139/v55-127

出版商:NRC Research Press    

年代:1955

数据来源: NRC

摘要:

A thioalkyl derivative has been synthesized by two distinct methods. One of these methods left no doubt as to the structural configuration. It is suggested that the other method of synthesis yields first an epoxy anhydro derivative which on further reaction leads to the thioalkyl carbohydrate, namely, 6-deoxy-6-thioethyl-D-galactose.

ISSN:0008-4042    

DOI:10.1139/v55-128

出版商:NRC Research Press    

年代:1955

数据来源: NRC

摘要:

The γ-ray irradiation conditions for the valid application of the Bragg-Gray relation, which relates the energy deposition in a solid to the ionization in an air-filled cavity, are examined with particular reference to some published experiments on the yield of the radiation-induced oxidation of ferrous sulphate. It is pointed out that experiments in which divergent radiation is used will give a higher oxidation yield than the relation indicates. A quantitative treatment is advanced which accounts for the discrepancies between certain experimental results.

ISSN:0008-4042    

DOI:10.1139/v55-129

出版商:NRC Research Press    

年代:1955

数据来源: NRC