A New Colorimetric Method for the Determination of Vanillin in Flavoring Extracts.

Folin, Otto; Denis, W.

doi:10.1021/ie50045a015

Cited by 48 publications

(30 citation statements)

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“…The magnesium factor in total fixed base, which according to the measurements of Rosemarm (3) is relatively minute, was disregarded. Nitrogen was determined by the micro Kjeldahl method of Folin and Denis (12).…”

Section: Chemical Methods Usedmentioning

confidence: 99%

The Acid-Base Composition of Gastric Secretions

Gamble

McIver

Matteson.³

1928

Journal of Experimental Medicine

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The chief inorganic factors in secretions obtained from isolated pouches constructed in the fundus and in the pyloric antrum of the cat's stomach were found to be chloride ion and fixed base. In a series of samples obtained from the fundic pouch, chloride ion was approximately stationary at 165 cc. 0.1 N per 100 cc. During digestion of food in the stomach, secretions from the pouch contained fixed base in amounts varying considerably from an average of 47 cc. 0.1 N per 100 cc. Material allowed to remain in the pouch after the completion of food digestion in the stomach showed an increasing content of fixed base, to as much as 140 cc. 0.1 N per 100 cc. A stationary total ionic content of secretions of the fundus is thus seen to be sustained by the chloride ion concentration, and changes in hydrogen ion concentration to be caused by variation of fixed base. The differing amounts of fixed base found are regarded as probably due to admixture of a mucous secretion with the juice from the fundic glands. The alkaline secretion taken from a pyloric pouch contained fixed base in excess of chloride ion. Variation of fixed base in the secretions from the fundic pouch were found to be referable to change in sodium content, the smaller factor, potassium, remaining approximately constant at about the value found in material from the pyloric pouch. This suggests that the mucous secretion of the fundus has the same composition as that produced by the pyloric antrum. These data will serve to explain the extensive withdrawal of fixed base, as well as of chloride ion, from the blood plasma in the presence of circumstances causing a continued loss of stomach secretions.

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Section: Chemical Methods Usedmentioning

confidence: 99%

The Acid-Base Composition of Gastric Secretions

Gamble

McIver

Matteson.³

1928

Journal of Experimental Medicine

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“…From this fact it appears that the tyrosine and tryptophane groups of proteins do not give their full color value by the pH 8.0 method. It is possible, of course, that 5 This property is not a peculiarity of the tyrosine phenol group for almost any phenol group gives rise to the characteristic blue color with the phenol reagent (10). The writer has found that no color was obtained by the pH 8.0 method when phenyl acetate or acetyl salicylic acid were used whereas they give the expected quantity of color by the pH 11.0 method.…”

Section: Determination Of Tyrosine Phenol Groupsmentioning

confidence: 99%

“…These three additional acetyl groups are rapidly hydrolyzed by molar acid or by alkali at pH 10.0, whereas the acetyl groups on the amino groups are not hydrolyzed under the same conditions. With this property in mind these easily hydrolyzed acetyl groups have been designated as "pH 10.0 labile" acetyl groups. There are three less tyrosine phenol groups in the 60 per cent active acetyl pepsin as measured colorimetrically with the Folin phenol reagent under conditions which will not hydrolyze an acetylated phenol.…”

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confidence: 99%

Acetylation of Tyrosine in Pepsin

Herriott

1935

Journal of General Physiology

114

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Crystalline 60 per cent active acetyl pepsin has 7 acetyl groups per mol of pepsin, 3 of which are readily hydrolyzed in acid at pH 0.0 or in weak alkali at pH 10.0. The tyrosine-tryptophane content of this acetylated pepsin, measured colorimetrically, is less than pepsin by three tyrosine equivalents. Hydrolysis at pH 0.0 or pH 10.0 of the 3 acetyl groups results in a concomitant increase in the number of tyrosine equivalents. In the pH 0.0 hydrolysis experiment there is also a simultaneous increase in specific activity. The phenol group of glycyl tyrosine is acetylated by ketene under the conditions used in the acetylation of pepsin and the effect of pH on the rate of acetylation is similar in the two cases. It is concluded that the acetyl groups in the 60 per cent active acetyl pepsin, which are responsible for the decrease in specific enzymatic activity, are 3 in number and are attached to 3 tyrosine phenol groups of the pepsin molecule.

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“…The urinary phenol and phenol esters. The method of Folin and Denis was used (18). The final color developed was read by the Pfalz and Bauer Photoelectric colorimeter.…”

Section: Methodsmentioning

confidence: 99%

Hepatic Vitamin a in the Rat as Affected by the Administration of Dibenzanthracene

Abels

Gorham

Eberlin

et al. 1942

Journal of Experimental Medicine

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1. The decreased concentrations of vitamin A in the livers of rats given dibenzanthracene probably are due to a particular effect of the carcinogen on the ability of the liver to store the vitamin and not to the production of general hepatic dysfunction. 2. The administration of dibenzanthracene to normal rats does not (a) increase significantly their hepatic content of total fat nor decrease that of phospholipid; (b) impair the ability of their livers to fabricate serum albumin; (c) impair the capacity of their livers to esterify cholesterol or phenol; (d) interfere with the hepatic synthesis and conjugation of glucuronic acid; or (e) interfere with the hepatic storage of riboflavin. 3. The simultaneous ingestion of yeast by the dibenzanthracene-treated rats further depletes their hepatic stores of vitamin A. This depletion conceivably is due to the fact that yeast alone also might deplete the liver of its vitamin A and thus a summation of two similar effects is attained. 4. The results suggest a competition between vitamin A and dibenzanthracene for some substance, possibly a protein, to which vitamin A may be bound in the liver.

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A New Colorimetric Method for the Determination of Vanillin in Flavoring Extracts.

Cited by 48 publications

References 0 publications

The Acid-Base Composition of Gastric Secretions

The Acid-Base Composition of Gastric Secretions

Acetylation of Tyrosine in Pepsin

Hepatic Vitamin a in the Rat as Affected by the Administration of Dibenzanthracene

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