Mixed Melting Point Curves of Some Dialkylbarbituric Acids1

1934 ◽  
Vol 56 (11) ◽  
pp. 2489-2490 ◽  
Author(s):  
H. A. Shonle ◽  
E. C. Kleiderer
Keyword(s):  
Melting Point ◽  
Mixed Melting Point

THE YELLOW COLORING MATTER OF KHAPLI WHEAT, TRITICUM DICOCCUM: II. THE CONSTITUTION OF TRICETIN

1932 ◽  
Vol 7 (3) ◽  
pp. 285-292 ◽  
Author(s):  
J. Ansel Anderson
Keyword(s):  
Melting Point ◽  
Related Compound ◽  
Mixed Melting Point ◽  
Water Soluble ◽  
Wheat Varieties ◽  
Wheat Leaves ◽  
Coloring Matter ◽  
Color Reactions ◽  
Hydrolysis Of ◽  
Derivatives Of

Khapli wheat leaves contain a very small quantity of a trihydroxydimethoxyflavone, tricin. Marquis yields a trace of the same compound. These two varieties also contain water-soluble coloring matters which are apparently glucosides of tricin or of a closely related compound. Dyeing tests carried out with six other wheat varieties indicate that all contain essentially the same coloring matters.Methylation of tricin and hydrolysis of the resulting O-trimethyltricin yielded 3,4,5-trimethoxybenzoic acid and 2-hydroxy-4,6-dimethoxyacetophenone. It was therefore assumed that tricetin, the pentahydroxyflavone derived from tricin, was 5,7,3′,4′,5′-pentahydroxyflavone. This was synthesized from 3,4,5-trimethoxybenzoic acid and phloracetophenone by the Allan-Robinson method. Mixed melting-point determinations showed that its O-pentamethyl and O-penta-acetyl derivatives are identical with the corresponding derivatives of tricetin. The dyeing properties and color reactions of synthetic and natural tricetin are identical and are in fair agreement with those described by Badhwar, Kang and Ventkataraman (3, p. 1111) who recently reported the synthesis of the same compound.

THE NORMAL C17 FATTY ACIDS OF MUSK-OX FAT

1957 ◽  
Vol 35 (12) ◽  
pp. 1434-1437 ◽  
Author(s):  
Mary J. Chisholm ◽  
C. Y. Hopkins
Keyword(s):  
Fatty Acids ◽  
Melting Point ◽  
Mixed Melting Point ◽  
Methyl Esters ◽  
Heptadecanoic Acid ◽  
X Ray Diffraction ◽  
Straight Chain ◽  
Trans Form ◽  
Total Fatty Acids ◽  
Musk Ox

A sample of body fat of the Canadian musk ox (Ovibosmoschatus subsp.) was converted to methyl esters and distilled. The fraction containing esters of C17 acids was crystallized fractionally at low temperature and two straight-chain C17 acids were isolated. n-Heptadecanoic acid was identified by analysis, by mixed melting point of the acid and two derivatives with authentic samples, and by its X-ray diffraction pattern. 9-Heptadecenoic acid was identified by analysis, by mixed melting point of two derivatives with authentic samples, and by oxidative cleavage. It is estimated that the fat contained 1.7% of n-heptadecanoic acid and 0.9% of cis-9-heptadecenoic acid, based on the total fatty acids. Although there was an appreciable content of trans acids in the fat, the heptadecenoic acid was found to contain little or none of the trans form.

scholarly journals Invertebrate connective tissue. Isolation of d-arabinose from sponge acidic polysaccharide

1970 ◽  
Vol 119 (1) ◽  
pp. 17-19 ◽  
Author(s):  
Richard L. Katzman ◽  
Elwira Lisowska ◽  
Roger W. Jeanloz
Keyword(s):  
Melting Point ◽  
Connective Tissue ◽  
Mixed Melting Point ◽  
Optical Rotation ◽  
Biological Role ◽  
Animal Kingdom ◽  
Rare Sugar ◽  
Acidic Polysaccharide

1. d-Arabinose, an extremely rare sugar in the animal kingdom, was isolated from a complex acidic polysaccharide obtained from the connective tissue of the sponge Hippospongia gossypina. A crystalline derivative of arabinose, the 1-benzyl-1-phenylhydrazone, was prepared and characterized by its melting point, optical rotation, and mixed melting point with authentic d- and l-enantiomers. 2. The distribution of arabinose within the animal kingdom is discussed, and a biological role is proposed for the spongonucleotides.

THE IDENTIFICATION OF A NINHYDRIN-POSITIVE URINARY COMPONENT RECENTLY REPORTED IN HYPOPHOSPHATASIA

1957 ◽  
Vol 35 (12) ◽  
pp. 1123-1133 ◽  
Author(s):  
Donald Fraser ◽  
C. C. Lucas
Keyword(s):  
Absorption Spectrum ◽  
Melting Point ◽  
Diffraction Pattern ◽  
Infrared Absorption ◽  
Mixed Melting Point ◽  
Infrared Absorption Spectrum ◽  
X Ray Diffraction ◽  
X Ray ◽  
Unequivocal Identification ◽  
Affected Infant

In 1955, the occurrence of a hitherto unreported ninhydrin-positive substance in the urine and plasma of infants suffering from hypophosphatasia was described. Evidence published at that time and subsequently suggested that the material might be phosphorylethanolamine, but the isolation and unequivocal identification of the substance has not been reported.The present paper describes the isolation of a small amount of the previously unidentified compound from the urine of the heterozygous father of a seriously affected infant. The melting point, mixed melting point, X-ray diffraction pattern, infrared absorption spectrum, and N: P ratio establish the identity of the substance to be phosphorylethanolamine. Proof that this compound occurs in hypophosphatasia provides a logical basis for further study of the metabolic importance of this substance.

scholarly journals THE CHEMICAL AND PHYSIOLOGICAL PROPERTIES OF CRYSTALLINE OESTROGENIC HORMONES

1933 ◽  
Vol 8 (2) ◽  
pp. 180-197 ◽  
Author(s):  
J. S. L. Browne
Keyword(s):  
Melting Point ◽  
Sex Hormones ◽  
Human Placenta ◽  
Mixed Melting Point ◽  
Albino Rat ◽  
Female Sex ◽  
Female Sex Hormones ◽  
Physiological Properties ◽  
Hydrogen Analysis

A crystalline oestrogenic hormone has been isolated from human placenta. This substance shows a melting point of 274 °C. (uncorrected). The carbon-hydrogen analysis gives: carbon, 74.8%; hydrogen, 8.8%. The mixed melting point with theelol shows no lowering. The substance differs physiologically from previously isolated female sex hormones. It is relatively inactive on the adult ovariectomized albino rat. The dose required is 16 γ as compared with 1.5 γ for theelol. It is, however, effective on the immature intact rat, 21 days old, in a dose of 1.2 γ. This is the same as theelol. On the immature castrate, the dose of the placental crystals is 10 γ, that for theelol is 3 γ. The presence of the ovary is believed to be the factor in the dosage ratio between adult spayed and normal intact animals. Transplantation of immature ovaries into immature or adult castrates, even though it does not render them cyclic, causes the weight of the placental crystals needed for an effect to fall to the immature intact dose.

THE IDENTIFICATION OF A NINHYDRIN-POSITIVE URINARY COMPONENT RECENTLY REPORTED IN HYPOPHOSPHATASIA

1957 ◽  
Vol 35 (1) ◽  
pp. 1123-1133
Author(s):  
Donald Fraser ◽  
C. C. Lucas
Keyword(s):  
Absorption Spectrum ◽  
Melting Point ◽  
Diffraction Pattern ◽  
Infrared Absorption ◽  
Mixed Melting Point ◽  
Infrared Absorption Spectrum ◽  
X Ray Diffraction ◽  
X Ray ◽  
Unequivocal Identification ◽  
Affected Infant

In 1955, the occurrence of a hitherto unreported ninhydrin-positive substance in the urine and plasma of infants suffering from hypophosphatasia was described. Evidence published at that time and subsequently suggested that the material might be phosphorylethanolamine, but the isolation and unequivocal identification of the substance has not been reported.The present paper describes the isolation of a small amount of the previously unidentified compound from the urine of the heterozygous father of a seriously affected infant. The melting point, mixed melting point, X-ray diffraction pattern, infrared absorption spectrum, and N: P ratio establish the identity of the substance to be phosphorylethanolamine. Proof that this compound occurs in hypophosphatasia provides a logical basis for further study of the metabolic importance of this substance.

scholarly journals Water-soluble metabolites of p-nitrophenol and 1-naphthyl N-methylcarbamate in flies and grass grubs. Formation of glucose phosphate and phosphate conjugates

1974 ◽  
Vol 144 (2) ◽  
pp. 303-310 ◽  
Author(s):  
M P Heenan ◽  
J N Smith
Keyword(s):  
Melting Point ◽  
Mixed Melting Point ◽  
Water Soluble ◽  
Glucose Phosphate

Metabolites isolated from houseflies dosed with 1-napththol or p-nitrophenol were identified as the phosphate and glucose phosphate conjugates of these phenols by titrations, hydrolysis, ionophoresis, i.r. spectra and mixed melting point. [3H]Carbaryl (1-naphthyl N-methylcarbamate) was metabolized by houseflies, blowflies and grass grubs to water-soluble metabolites which had chromatographic and ionophoretic behaviour similar to those of the conjugates of 1-naphthol with glucose, sulphate, phosphate and glucose 6-phosphate.

Reaction of Tetraethylthiuramdisulfide with Alkali and Its Bearing on Vulcanization Reactions

1962 ◽  
Vol 35 (3) ◽  
pp. 659-660 ◽  
Author(s):  
Teresa Gessner
Keyword(s):  
Melting Point ◽  
Sodium Hydroxide ◽  
Sulfur Content ◽  
Mixed Melting Point ◽  
Aqueous Sodium Hydroxide ◽  
Reaction Scheme ◽  
Reaction Products ◽  
Aqueous Sodium ◽  
Insoluble Material ◽  
Tetraethylthiuram Disulfide

Abstract Klebanski and Fomina have reported on the action of alkali on tetraethylthiuram disulfide (TETD). They suggested the following equation for the reaction: (see PDF for diagram) This equation is based in part on a premise that TETM is one of the reaction products; we feel this premise is incorrect. As partial evidence for their proposed reaction scheme, Klebanski and Fomina claim the isolation of tetraethylthiurammonosulfide (TETM) from the reaction products. They give both the analysis figures and the melting point of the isolated substance. The melting point quoted by them is 64–65°. The melting point of TETM is, however, 28–33°. We have attempted the isolation of the substance reported by Klebanski and Fomina, and have repeated their experiment according to the published instructions. The only water-insoluble material which we were able to isolate, after 8 hours reaction with 2% aqueous sodium hydroxide, was unreacted TETD (73% of the starting material). The material isolated had a melting point of 68.5–70°, mixed melting point with TETD was 68.5–70°, the nitrogen and sulfur content was: %N 9.38, %S 42.82. Recrystallized from ether the substance melted at 70°, and analyzed as: %N 9.48, %S 43.05, mol. wt. 297; TETD requires; %N 9.53, %S 42.93, mol. wt. 296, m. pt. 70°.

Voids in Irradiated Tungsten and Molybdenum

1969 ◽  
Vol 27 ◽  
pp. 190-191
Author(s):  
Robert C. Rau ◽  
Robert L. Ladd
Keyword(s):  
Melting Point ◽  
Fast Neutron ◽  
Neutron Irradiation ◽  
Elevated Temperatures ◽  
Irradiation Temperature ◽  
The Body ◽  
Face Centered Cubic ◽  
Body Centered Cubic ◽  
Cubic Metals ◽  
Face Centered

Recent studies have shown the presence of voids in several face-centered cubic metals after neutron irradiation at elevated temperatures. These voids were found when the irradiation temperature was above 0.3 Tm where Tm is the absolute melting point, and were ascribed to the agglomeration of lattice vacancies resulting from fast neutron generated displacement cascades. The present paper reports the existence of similar voids in the body-centered cubic metals tungsten and molybdenum.

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