The Purification and Fractionation of Rubber. (7th Communication)

1929 ◽  
Vol 2 (3) ◽  
pp. 367-372 ◽  
Author(s):  
Rudolf Pummerer ◽  
Albrecht Andriessen ◽  
Wolfgang Gündel
Keyword(s):  
Aqueous Solution ◽  
Amino Acids ◽  
Nitrogen Content ◽  
Amino Nitrogen ◽  
Prolonged Treatment ◽  
Protein Nitrogen ◽  
De Vries ◽  
Ninhydrin Reaction ◽  
Long Storage

Abstract I—The Alkali Purification of Concentrated Latex. Nitrogenous Impurities in Latex Preserved with Ammonia It has already been shown that in the purification of latex by alkali, fresh and ammonia-preserved latex behave differently toward alkali. The former is changed even in the cold through decomposition of the proteins (as shown independently by de Vries and Beumée-Nieuwland), whereas the latter first shows evidences of changes at 50°, at which point it creams. Furthermore, experiments with “Revertex”, a concentrated latex, have shown that ammonia-preserved latex is changed in a still different way. Pummerer and Pahl consider the “total rubber”, obtained by them from ammonia-preserved latex by the action of alkali, to be free proteins and nitrogen. This view is, however, open to correction. Total rubber is probably fairly free of proteins, but contains nitrogen. The nitrogen content, which is still appreciable even after prolonged treatment with alkali at 50??, varies from 0.15 to 0.4%. This nitrogen was at first overlooked, because it was not detected in a few qualitative Lassaigne tests, nor in a quantitative Dumas determination. Moreover analysis indicated nearly 100% of hydrocarbon. Nevertheless new tests have shown that many samples contained 0.4% nitrogen. When the samples were incinerated with a reduced copper spiral, there was a deficit of 0.4% in the carbon-hydrogen determinations. Accordingly a substance containing 0.4% protein-nitrogen would show a deficit of about 1% on account of the oxygen in the protein. The nitrogen remaining after the alkali purification of ammonia-preserved latex is not protein-nitrogen but amino-nitrogen, which probably is formed by the action of ammonia during long storage. A gel-rubber (0.4% nitrogen) refluxed in benzene for a day with dilute NaOH yielded no amino acids to the NaOH. The neutralized aqueous solution did not give the ninhydrin reaction, nor did the rubber itself when it was boiled with the reagent.

The influence of diet on the nitrogenous components passing to the duodenum and through the lower ileum of sheep

1966 ◽  
Vol 166 (1002) ◽  
pp. 63-79 ◽  
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Nitrogen Content ◽  
Aspartic Acid ◽  
Total Nitrogen ◽  
Amino Nitrogen ◽  
Terminal Part ◽  
High Nitrogen ◽  
Low Nitrogen ◽  
Lower Ileum

Analyses of the alimentary contents flowing to the duodenum of sheep during 24 h show that when the sheep are consuming a low-nitrogen diet more total nitrogen and amino nitrogen pass to the duodenum than are eaten daily in the food whereas when the sheep are eating high nitrogen diets, less total nitrogen and less amino nitrogen pass to the duodenum. The disparity between the total nitrogen and amino nitrogen content of the diets largely disappeared by the time the alimentary contents reached the terminal part of the ileum. From 64 to 68% of the nitrogen entering the duodenum and 54 to 64% of the nitrogen in the ileal contents was in the form of amino nitrogen. Proportionately more of the amino nitrogen was in solution in the ileal contents than in the duodenal contents. Losses of amino acids in the stomach when a high-nitrogen diet was consumed were especially large for glutamic acid, aspartic acid, proline, arginine and leucine. They were least for cystine and threonine. Gains of amino acids in the stomach when low nitrogen diets were consumed were all substantial except for proline, where a loss was found when hay and flaked maize were given. When these changes are considered as proportions of the quantities eaten then trends are similar for all acids. Changes in the molar proportions of the amino acids present in hydrolysates of the duodenal and ileal contents are discussed together with the significance of these changes in relation to the nutrition of the sheep.

Action of proteolytic enzymes on wheat gluten

1968 ◽  
Vol 46 (9) ◽  
pp. 1019-1022 ◽  
Author(s):  
Hung-Ju Yang ◽  
A. G. McCalla
Keyword(s):  
Amino Acids ◽  
Free Amino ◽  
Proteolytic Enzymes ◽  
Wheat Gluten ◽  
Amino Nitrogen ◽  
Protein Nitrogen ◽  
Early Stages ◽  
Mean Size ◽  
Terminal Amino ◽  
The Mean

Papain and trypsin partially hydrolyzed wheat gluten dispersed in 10% sodium salicylate, and pepsin partially hydrolyzed gluten dispersed in aluminium lactate. Trypsin was considerably less effective than either papain or pepsin. Papain produced non-protein nitrogen most rapidly during early stages of hydrolysis but pepsin produced the largest total after 48 h. The rate of release of terminal amino nitrogen was similar for papain and pepsin, and release was not complete after 48 h. The mean size of polypeptides was larger in papain than in pepsin hydrolysates during early stages of hydrolysis but definitely smaller after 48 h. Only pepsin released appreciable amounts of free amino acid nitrogen. Leucine and phenylalanine made up over 50% of the free amino acids after 48 h but several other amino acids were found in significant quantities.

scholarly journals THE ABNORMAL COURSE OF BACTERIAL PROTEIN SYNTHESIS IN THE PRESENCE OF PENICILLIN

1950 ◽  
Vol 91 (4) ◽  
pp. 351-364 ◽  
Author(s):  
Rollin D. Hotchkiss
Keyword(s):  
Amino Acids ◽  
Amino Nitrogen ◽  
Cellular Protein ◽  
Penicillin G ◽  
Bacterial Protein ◽  
Protein Nitrogen ◽  
Amino Acid Nitrogen ◽  
Extracellular Substances ◽  
Bacterial Protein Synthesis ◽  
Peptone Broth

Washed staphylococcal cells separated from peptone-broth cultures containing penicillin G did not differ markedly from cells not exposed to penicillin in their rate of oxygen, phosphate, glutamic acid, or amino nitrogen utilization. Washed normal staphyloccal cells, respiring in solutions containing glucose and various mixtures of amino acids, utilized the amino acids with an increase in the cellular protein nitrogen. Similar cells under the same conditions, but exposed to penicillin G, utilized oxygen, phosphate, and amino acids at essentially the same rates, but there was no increase in the protein nitrogen of the cells. Penicillin-treated washed cells, when utilizing amino acids, produced increased amounts of extracellular substances containing non-amino nitrogen in quantities approximately equivalent to the amino acid nitrogen utilized. The non-amino fraction could be tentatively identified as polypeptide, which was produced, instead of cellular protein, when penicillin was present.

Effects of Nitrogen Source and Concentration on the Free Amino Acid Composition of Developing Wheat Grains

1990 ◽  
Vol 17 (2) ◽  
pp. 199 ◽  
Author(s):  
C Blumenthal ◽  
JW Lee ◽  
EWR Barlow ◽  
IL Batey
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Ammonium Nitrate ◽  
Amino Acid Composition ◽  
Free Amino Acid ◽  
Acid Composition ◽  
Free Amino ◽  
Amino Nitrogen ◽  
Grain Protein ◽  
Protein Nitrogen

Detached wheat heads (7 days post-anthesis) were grown in liquid culture containing nitrogen concentrations of 0.025% or 0.1% in the form of glutamine, ammonium nitrate or asparagine. With each form of the nitrogen, increasing the concentrations of nitrogen in the culture medium led to increases in the total nitrogen and the non-protein nitrogen in the grain. Protein contents (N × 5.7) were approximately 16% and 21% on a dry weight basis in the low and high treatments respectively for all nitrogen sources. Amino acids from the endosperm cavity, the ethanol-soluble extract of the grain, and the grain protein were analysed by HPLC techniques to define the site of transfer between amino acid forms. The results indicated that amino nitrogen from glutamine, ammonium nitrate, or asparagine enters the grain and is found in the endosperm cavity fluid mainly in the form of glutamine, alanine and, to a lesser extent, aspartate (including asparagine). These amino acids are then converted into the various other amino acids required for protein synthesis, as is demonstrated by the increases found in the others in the ethanol-soluble free amino acid fraction with different nitrogen regimes. These variations in the composition of the free amino acids occurred without altering the amino acid composition of the protein component of the grain.

The non-protein nitrogen composition of grass silage:III. The composition of spoilt silages

1971 ◽  
Vol 76 (3) ◽  
pp. 329-336 ◽  
Author(s):  
A. D. Hughes
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Nitrogen Content ◽  
Ammonia Nitrogen ◽  
Water Soluble ◽  
Protein Nitrogen ◽  
High Ph ◽  
Selective Degradation ◽  
Amino Acid Nitrogen ◽  
Three Samples

SUMMARYThe nitrogenous composition of the water soluble, non-protein nitrogen fractions of three samples of high-pH-spoilt silage and one sample of overheated silage were examined in detail. The amino acid nitrogen content of the high-pH-spoilt silages declined with increasing extent of spoilage, due to a selective degradation of the amino acids. Losses of amino acids were associated with proportionate increases in the amount of volatile basic nitrogen. Lower aliphatic amines were not present and it was therefore concluded that the ultimate end product of nitrogen metabolism in high-pH-spoilt silages was ammonia. Only low concentrations of putrefaction products, such as putroscine, cadaverine and histamine were present.The composition of the non-protein nitrogen fraction of the overheated silage was unusual in that the ammonia nitrogen content was high and associated with the complete destruction of certain amino acids. The free amino acid nitrogen content was low but this was partially compensated for by a very high ‘peptide’ nitrogen content. There was no evidence of putrefaction products in this silage.

scholarly journals STUDIES IN LIVER AND KIDNEY FUNCTION IN EXPERIMENTAL PHOSPHORUS AND CHLOROFORM POISONING

1915 ◽  
Vol 22 (3) ◽  
pp. 333-346 ◽  
Author(s):  
E. K. Marshall ◽  
L. G. Rowntree
Keyword(s):  
Amino Acids ◽  
Renal Insufficiency ◽  
Amino Nitrogen ◽  
Ion Concentration ◽  
Protein Nitrogen ◽  
Hydrogen Ion Concentration ◽  
Functional Changes ◽  
Phosphorus Poisoning ◽  
Renal Changes ◽  
Liver And Kidney

1. We have confirmed the results of previous workers on tetrachlorphthalein, fibrinogen, and lipase. 2. The total non-protein nitrogen, urea, and amino-acids of the blood serum show a definite and sometimes marked increase in phosphorus poisoning. These changes are not so evident in chloroform poisoning, although they sometimes occur. They are usually terminal phenomena. 3. The urinary nitrogen partition between the urea, ammonia, and amino-acids is not always disturbed. The most important changes which occur are an increased amino nitrogen in chloroform and phosphorus poisoning, and a very low urea nitrogen percentage in severe fatal chloroform poisoning. 4. Sugar tolerance towards galactose and levulose is in general markedly decreased in both types of poisoning. 5. In phosphorus poisoning liver functional changes can and do occur without concomitant renal changes. Renal insufficiency usually arises as a terminal event. 6. Increased nitrogenous products in the blood (total non-protein nitrogen, urea, and amino nitrogen) are associated with an increase of these bodies in the urine. Consequently, an increased protein catabolism, as well as renal insufficiency, is necessary to explain this accumulation. 7. A terminal acidosis, as evidenced by increased hydrogen ion concentration in the blood, usually occurs.

scholarly journals BIOCHEMICAL STUDIES ON SHOCK

1944 ◽  
Vol 79 (1) ◽  
pp. 9-22 ◽  
Author(s):  
Frank L. Engel ◽  
Helen C. Harrison ◽  
C. N. H. Long
Keyword(s):  
Blood Pressure ◽  
Amino Acids ◽  
Oxygen Saturation ◽  
Hepatic Artery ◽  
Arterial Oxygen Saturation ◽  
Amino Nitrogen ◽  
Arterial Oxygen ◽  
High Positive Correlation ◽  
Peripheral Tissues ◽  
Arterial Blood

1. In a series of rats subjected to hemorrhage and shock a high negative correlation was found between the portal and peripheral venous oxygen saturations and the arterial blood pressure on the one hand, and the blood amino nitrogen levels on the other, and a high positive correlation between the portal and the peripheral oxygen saturations and between each of these and the blood pressure. 2. In five cats subjected to hemorrhage and shock the rise in plasma amino nitrogen and the fall in peripheral and portal venous oxygen saturations were confirmed. Further it was shown that the hepatic vein oxygen saturation falls early in shock while the arterial oxygen saturation showed no alteration except terminally, when it may fall also. 3. Ligation of the hepatic artery in rats did not affect the liver's ability to deaminate amino acids. Hemorrhage in a series of hepatic artery ligated rats did not produce any greater rise in the blood amino nitrogen than a similar hemorrhage in normal rats. The hepatic artery probably cannot compensate to any degree for the decrease in portal blood flow in shock. 4. An operation was devised whereby the viscera and portal circulation of the rat were eliminated and the liver maintained only on its arterial circulation. The ability of such a liver to metabolize amino acids was found to be less than either the normal or the hepatic artery ligated liver and to have very little reserve. 5. On complete occlusion of the circulation to the rat liver this organ was found to resist anoxia up to 45 minutes. With further anoxia irreversible damage to this organ's ability to handle amino acids occurred. 6. It is concluded that the blood amino nitrogen rise during shock results from an increased breakdown of protein in the peripheral tissues, the products of which accumulate either because they do not circulate through the liver at a sufficiently rapid rate or because with continued anoxia intrinsic damage may occur to the hepatic parenchyma so that it cannot dispose of amino acids.

A colorimetric chemosensor for the sequential detection of copper ion and amino acids (cysteine and histidine) in aqueous solution

RSC Advances ◽  
2015 ◽  
Vol 5 (39) ◽  
pp. 31179-31188 ◽  
Author(s):  
Yong Sung Kim ◽  
Gyeong Jin Park ◽  
Seul Ah Lee ◽  
Cheal Kim
Keyword(s):  
Aqueous Solution ◽  
Amino Acids ◽  
Copper Ion ◽  
Sequential Detection ◽  
Colorimetric Chemosensor

A simple and selective colorimetric chemosensor was reported for the sequential detection of Cu2+, cysteine and histidine.

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